# Sticky  Finding a motor on a budget



## sukusia (Mar 25, 2011)

So here is what I learned about motors from this site. I wanted to post a quick reference so newbs (like myself) do not have to sort through the sticky page.

*When looking for a forklift motor:*
Get a series wound motor because they have very high torque and handle abuse (over volting) a lot better.
Know the difference between a Spex motor and a Series wound.
When dealing with series wound forklift motors go for higher voltage. (36V may require advanced timing.)
Hp does not directly represent torque (although it does have a factor in its equation).
Get a class H insulation if possible (makes your motor last longer)
Get a motor around 150lbs (Wouldn't risk a motor that's too light, it won't have the oomph you need. a few extra pounds is A-o.k. but a significant amount of extra pounds limits your range)
Get one with a male shaft
A keyed shaft is easier to work with but you can still work with a spline shaft
Try and get the coupler that goes on to your motor when you buy it/rip it out (saves you $$ and time)
*When looking for a different motor:*
Ac is not the way to go for your first conversion (or do i just have low expectations of myself?)
You can tell if a motor is AC if it is a 1 phase or 3 phase motor
Pancake motors are usually not good candidates for car conversions. (Yeah you saw the one on ebay. They overheat easily)
Golfcart motors are seldom powerful enough for a conversion
Motors specifically made for EV conversions are the best but its gonna cost you.
You do have to look at many factor such as volts, amps (which gets you Hp). Torque is nice to know. Continuous Hp. So many factors!!!


> "HP is HP Electric motors and gas engines are rated differently w/r/t HP. And they have different torque curves. But one HP from an electric motor shaft is exactly the same as one HP from a gas engine shaft at the same RPM "- Major


If there is any more helpful hints I'll be happy to add them


----------



## major (Apr 4, 2008)

sukusia said:


> So here is what I learned about motors from this site. I wanted to post a quick reference so newbs (like myself) do not have to sort through the sticky page. Correct me if i'm wrong on these.


Hi suk,

Not bad  Here's a couple of comments. Refer back to your #1 post for quote context.



> (36V usually is too low)


Not necessarily. Many 36V motors work out well for guys on 72 or 96V systems, some even higher. That usually requires advance (shifting the brush position).



> A heavier one is o.k. but it limits your range


Unless you go way overboard, I doubt you need to worry about a few motor pounds subtracting from your range. 



> Hp from an electric motor is not the same as Hp from an Gasoline engine


HP is HP  Electric motors and gas engines are rated differently w/r/t HP. And they have different torque curves. But one HP from an electric motor shaft is exactly the same as one HP from a gas engine shaft at the same RPM 

Regards,

major


----------



## sukusia (Mar 25, 2011)

Thank you for your input major. You are the motor master after all. Doh on my part for the HP thing. I kinda have to laugh at myself for that one. I think I'll change my top post to correct and clarify things for newbs like me.

Thanks


----------



## AC or DC (Mar 26, 2011)

A query I have is finding a source for a forklift motor. Other than purchasing a wrecked forklift I have seen information about picking them up from servicing and repair places. However if a motor is being thrown out then surely it is not going to be worth salvaging for using in an electric car conversion. If it won't work in a forklift any more then to me it follows that it is only suitable as scrap. Please any advice gratefully received.


----------



## Woodsmith (Jun 5, 2008)

AC or DC said:


> A query I have is finding a source for a forklift motor. Other than purchasing a wrecked forklift I have seen information about picking them up from servicing and repair places. However if a motor is being thrown out then surely it is not going to be worth salvaging for using in an electric car conversion. If it won't work in a forklift any more then to me it follows that it is only suitable as scrap. Please any advice gratefully received.


I have a local motor service place near me and they have quite a few motors 'in stock'.

Often a dead motor is brought in and found uneconomical to repair or the turn over time is too long and so a new or recon motor is sold in exchange. The dead one is then repaired when work is quiet and place on the shelf for sale. Occasionally they have also repaired motors and the customer never returns for it, some are even paid for and abandoned.

So it is worth asking and you should get a rebuilt motor with a warrenty on the work.

However, the other way is to find a fork lift breaker. They will often remove running motors and sell them with no more warrenty then that it spins on 12V. You may then, if is is rough, be taking it back to the repair shop to have it rebuilt anyway. But you could also be lucky and get a really good one that require only a clean and new brushes and bearings.


----------



## Woodsmith (Jun 5, 2008)

I am going to make this thread a 'sticky'.

Please post concise useful hints and tips, maybe with helpful images, here to help members and keep the 'is this one any good (with photos)' and the 'chat' about them in the other sticky thread please.

Thank you.


----------



## sukusia (Mar 25, 2011)

AC or DC said:


> A query I have is finding a source for a forklift motor. Other than purchasing a wrecked forklift I have seen information about picking them up from servicing and repair places. However if a motor is being thrown out then surely it is not going to be worth salvaging for using in an electric car conversion. If it won't work in a forklift any more then to me it follows that it is only suitable as scrap. Please any advice gratefully received.


 I bough Ben Nelson's Build your own electric car cheap DvD where Ben gives a brief explanation on how to repair an electric motor. The motor Ben used barley turned and was rusted on the case badly. But he made it run. Its not that expensive from what i saw ($50). Another factor to consider is the price of batteries. These old forklifts may still be running but as they grow older the value of the batteries actually cost more than the forklift itself. So what do these companies do? They scrap the forklift. Why buy new batteries for an old forklift when you can have newer batteries and a new forklift?
Finding one can be difficult in certain areas. I talked to a friend of mine and he said that all the big company's with the forklifts you want send the broken-down/old forklifts to the scrap yard. Most of the time for insurance purposes big companies cannot sell it to someone. So your best bet is either surf the web or call multiple scrap yards and ask them to call you if they ever get a forklift in.

My 2 cents


----------



## AC or DC (Mar 26, 2011)

Thanks for those useful comments people. They have given me a few ideas.


----------



## electro37 (May 18, 2008)

sukusia said:


> So here is what I learned about motors from this site. I wanted to post a quick reference so newbs (like myself) do not have to sort through the sticky page.
> 
> *When looking for a forklift motor:*
> Get a series wound motor because they have very high torque and handle abuse (over volting) a lot better.
> ...


Anywhere where the "metric-sytem" is used; there is no use of the word Horse Power, it is a forbidden-word in the Euro-Union, to the extent, if a student doing an exam uses the word ,horse-power he automatically voids his answer!!!!!!!!!!!! Some examiners were willing to fail your whole "paper" in Europe during the "changeover" to metric.


----------



## sukusia (Mar 25, 2011)

electro37 said:


> Anywhere where the "metric-sytem" is used; there is no use of the word Horse Power, it is a forbidden-word in the Euro-Union, to the extent, if a student doing an exam uses the word ,horse-power he automatically voids his answer!!!!!!!!!!!! Some examiners were willing to fail your whole "paper" in Europe during the "changeover" to metric.


Good thing I'm not in Europe then.


----------



## Duncan (Dec 8, 2008)

_Anywhere where the "metric-sytem" is used; there is no use of the word Horse Power, it is a forbidden-word in the Euro-Union,_

*COBBLERS*!

The demon word - Horsepower - is frequently used - the only problem is that there are lots of different -horsepowers-, SAE, DIN, PS 

I have taken numerous European technical papers - and set a few - and I have never heard of anybody being penalized for using the word - horsepower

Mind you if you tried to answer a technical question in horsepower instead of Kw I would have marked it wrong - just as I would have if you answered a distance question in Roman miles

Have you ever tried to do any serious engineering work in the Imperial system?
It's bloody hard - Rotary Slugs for example

*during the "changeover" to metric.*

I remember the UK as the last country in Europe to "changeover" - but that was over forty years ago!!


----------



## electro37 (May 18, 2008)

Duncan said:


> _Anywhere where the "metric-sytem" is used; there is no use of the word Horse Power, it is a forbidden-word in the Euro-Union,_
> 
> *COBBLERS*!
> 
> ...


I was threatened in England just after the "changeover" to metric, just before starting a Marine Engineering exam, and again in Canada when starting a "Stationary Engineer's" exam also. But; I guess nobody in both countries "cares a damn" which you use theses days!! In England most "speed signs are in both! Here in Canada there was talk about doing the same, posting in both MPH and KPH.... In a lot of calculations it is easier to use metric, but that is the only advantage I can see.


----------



## Duncan (Dec 8, 2008)

Hi Electro

_*In a lot of calculations it is easier to use metric, but that is the only advantage I can see.*_

Just try to calculate driveshaft resonant frequencies in Imperial! - nevermind anything difficult

The real advantage is that SI is a designed set of measurements so that everything keys together

This is a *major* advantage when you are trying to understand what is going wrong

Imperial is a set of almost random units related to the size of somebodies foot and the width of a horses arse thousands of years ago


----------



## josmeijer (Apr 24, 2011)

The horesepower we use for electric motors here in Europe is rather straightforeward.

it´s 1,36 horespower roughly in a kw.
all other horsepowers (EPK, IPK etc) are long forgotten, though they might be used by vague merchants to whip up the power (just like speaker-watts)

But type-plates are reliable enough to stick to the */1,36 to use in your calculations.


----------



## execelon7 (Jan 25, 2008)

sukusia said:


> So here is what I learned about motors from this site. I wanted to post a quick reference so newbs (like myself) do not have to sort through the sticky page.
> 
> I have always wanted to build a EV but I dont have the knowledge of the motors or the electrics involved. After reading many posts here I think I may be able to do it with help from all of you. I have mechanical skills I did a engine conversion on a Rx7 to chevy 4.3l v-6 4bbl , 700r4 trans. So here is where I am now. I posted this earlier ,I'll paste it here with the link to the pics. Any advice, info comments WELCOME.
> 04/29/2000 DAY ONE
> ...


----------



## josmeijer (Apr 24, 2011)

no worries, you won´t wreck any motor if you test it on a lower voltage as it is designed for, if it is able to run freely.


----------



## execelon7 (Jan 25, 2008)

josmeijer said:


> no worries, you won´t wreck any motor if you test it on a lower voltage as it is designed for, if it is able to run freely.


Does this diagram look right to you

http://s1237.photobucket.com/albums/ff466/UNED2GETBENT/?action=view&current=MTRDRW11.jpg


----------



## DawidvC (Feb 14, 2010)

If I may assume that speaking about the front, you are meaning the Drive End (i.e. the part where the shaft exits that is going to be connected to the gearbox, and NOT the part that house the brushes) AND we can assume that the motor is wired standard, then your drawing would be correct.

Regards
Dawid


----------



## execelon7 (Jan 25, 2008)

DawidvC said:


> If I may assume that speaking about the front, you are meaning the Drive End (i.e. the part where the shaft exits that is going to be connected to the gearbox, and NOT the part that house the brushes) AND we can assume that the motor is wired standard, then your drawing would be correct.
> 
> Regards
> Dawid


Thank you so much for your reply,
Roger


----------



## Tyner1988 (May 10, 2011)

*Re: Finding a motor on a budget 2 motors available*

I have 2 electric motors made by Polaron & marketed under the name of Nelco. It has a peak torque of 60kw. It was originally developed for medium sized buses & large vans. They have never been used to my knowledge but have been in sotrage for a while. 2 links below give some info close to the motors I have. If interested I can send pics and maybe work out a deal. You can call email me at [email protected].

http://www.coopercontrols.co.uk/components/motors.htm

http://www.coopercontrols.co.uk/components/n200ml.htm


----------



## Vikingdad (May 22, 2011)

OK, I'm a Noob. I have an industrial electric motor that is rated at 10HP, 240V A/C 3 Phase. It weighs a heck of a lot, well over 100 lbs. 

I also have a 10KW generator, again 3 phase and 240 volt. (This thing weighs a TON!!!!) 

How would these two motors compare to one another and would either of them be suitable for an electric conversion powerplant?


----------



## major (Apr 4, 2008)

Vikingdad said:


> OK, I'm a Noob. I have an industrial electric motor that is rated at 10HP, 240V A/C 3 Phase. It weighs a heck of a lot, well over 100 lbs.
> 
> I also have a 10KW generator, again 3 phase and 240 volt. (This thing weighs a TON!!!!)
> 
> How would these two motors compare to one another and would either of them be suitable for an electric conversion powerplant?


Hi Vik,

One is likely an induction motor and the other an alternator (synchronous machine). Neither would be a good choice for a rookie EV builder. AC motors require inverter type controllers typically costing more than DC converter controllers. Standard 240VAC machines mean battery pack voltage on the order of 300VDC. This increases the cell count, and cost of associated equipment for the battery like management and charger.

Regards,

major


----------



## hbthink (Dec 21, 2010)

Just made an ebay purchase of a 3-phase AC motor rated as following

Motor label specs: 
Water cooled 
keyed shaft dia=.75" x 2.6"
Torque 22.2Nm
Speed 4500rpm
Voltage 54.5
Current 136A 

Hoping I can push the voltage higher and get enough torque for my 1800 lbs of 83 VW Rabbit. At least its water cooled, I thought that was worth the $500 purchase price. That shaft size and the fact that it is keyed much like my FB4001A is also nice

Steve


----------



## DawidvC (Feb 14, 2010)

To see how much that motor can be overvolted, you need to know the voltage / frequency ratio of that motor. This can be calculated if you know what the base speed of the motor is. That should normally be the speed (in rpm) where the torque would start to fall off. Using that speed and knowing how many pole-pairs the motor has, would allow you to calculate the frequency needed to achieve base speed, and thence your v/f ratio.

Good luck with your build
Dawid


----------



## Spider-man (May 9, 2011)

I have seen a few people use aircraft starter motors in some conversions. Where do you obtain one of those?


----------



## cruisin (Jun 3, 2009)

Spider-man said:


> I have seen a few people use aircraft starter motors in some conversions. Where do you obtain one of those?


Aircraft surplus stores near Oakland Airport Oakland, CA.


----------



## tropes (Jul 24, 2011)

So I just bought this rolling junior dragster and plan to convert it to electric. The motor that seems to fit is a 48 volt Brush-Type Permanent Magnet DC Motor from Electricmotorsport.com. The battery would be four 
PC625 Odyssey drycell batteries. All my research says I should also buy a controllor. Can you tell me why I cannot just use an appropriate on-off switch to turn on the motor? Okay, so I checked around and found that there are no simple mechanical switch that won't weld contacts at this DC wattage. So what is the way to go?
Tropes


----------



## Spider-man (May 9, 2011)

tropes said:


> So I just bought this rolling junior dragster and plan to convert it to electric. The motor that seems to fit is a 48 volt Brush-Type Permanent Magnet DC Motor from Electricmotorsport.com. The battery would be four
> PC625 Odyssey drycell batteries. All my research says I should also buy a controllor. Can you tell me why I cannot just use an appropriate on-off switch to turn on the motor? Okay, so I checked around and found that there are no simple mechanical switch that won't weld contacts at this DC wattage. So what is the way to go?
> Tropes


 
The things I have seen mose is people will basically cut a normal section out of their main cable and add a plastic box and a handle to it. so that way it is like a giant removable section between the batteries and everything else for an emergency "kill switch" if you will. I saw a few people do it on youtube that way. I think the white zombie may be that way. I could be wrong tho...


----------



## Guest (Aug 9, 2011)

I have two. One connected to the old Kaylor adaptor plate for the VW. Sweet setup but best only for the lightweight buggy or kit car. Not for high speeds either but they do work. Can't over speed these puppies either. They may also make a nice DC generator for folks. I have some stuff on youtube too. 

http://www.youtube.com/watch?v=2UtQuiiWAks


----------



## tropes (Jul 24, 2011)

Thanks guys. I think I'll keep looking.
tropes


----------



## ez2gonuts (Aug 25, 2011)

Is it possible to use a power converter to 110 ac and use a 110 electrict
motor


----------



## Jan (Oct 5, 2009)

ez2gonuts said:


> Is it possible to use a power converter to 110 ac and use a 110 electrict
> motor


If you mean with 'power converter' a regular 12Vdc to 110Vac inverter, I would guess: yes. BUT. They normally are not much higher rated than 1 kW maybe some up till 3 kW. Just enough to power a washing machine. Or a bike. But more important: How are you going to control the power? It's just on or off.


----------



## major (Apr 4, 2008)

ez2gonuts said:


> Is it possible to use a power converter to 110 ac and use a 110 electrict
> motor


Short answer....NO 

I suppose you're talking about those 12VDC to 110VAC inverters sold to run AC stuff from your car battery. Those mostly are not sine wave and are single phase. For EV propulsion motor, you need 3 phase, and variable frequency on top of that.

Other issues also 

major


----------



## Jan (Oct 5, 2009)

major said:


> Short answer....NO
> 
> I suppose you're talking about those 12VDC to 110VAC inverters sold to run AC stuff from your car battery. Those mostly are not sine wave and are single phase. For EV propulsion motor, you need 3 phase, and variable frequency on top of that.
> 
> ...


 
http://www.samlexamerica.com/products/productdescription.asp?ProductsID=20030

And there do exists single phase AC motors too. A lot.

Just to be wright for once.


----------



## Spider-man (May 9, 2011)

Jan said:


> If you mean with 'power converter' a regular 12Vdc to 110Vac inverter, I would guess: yes. BUT. They normally are not much higher rated than 1 kW maybe some up till 3 kW. Just enough to power a washing machine. Or a bike. But more important: How are you going to control the power? It's just on or off.


I have actually done research on this. I have an AC motor that is rated at 1/2 hp. the max amps it will take is around 7 (I think) tops 8... so, as long as you buy a $70ish dollar inverter on the internet (capable of the max wattage of the motor for long periods of time) and couple it to a speed controller of some sort it should work. The "controller" would usually include a pot as well.

here is the one I am considering:
http://www.cshincorporated.com/product_info.php/cPath/122_39/products_id/138

good luck!


----------



## tropes (Jul 24, 2011)

> *When looking for a different motor:*
> Ac is not the way to go for your first conversion (or do i just have low expectations of myself?)
> You can tell if a motor is AC if it is a 1 phase or 3 phase motor
> Pancake motors are usually not good candidates for car conversions. (Yeah you saw the one on ebay. They overheat easily)
> ...


I have just purchased a slightly used K91- 4003, 72 volt motor for my junior dragster conversion. Is anyone here using this motor and if so, what are you using for battery, controller, throttle,contactor?
Tropes


----------



## Spider-man (May 9, 2011)

gottdi said:


> I have two. One connected to the old Kaylor adaptor plate for the VW. Sweet setup but best only for the lightweight buggy or kit car. Not for high speeds either but they do work. Can't over speed these puppies either. They may also make a nice DC generator for folks. I have some stuff on youtube too.
> 
> http://www.youtube.com/watch?v=2UtQuiiWAks


What are the specs on the motor you are using gottdi?


----------



## EVfun (Mar 14, 2010)

Jan said:


> And there do exists single phase AC motors too. A lot.
> 
> Just to be wright for once.


But can you find a single phase AC motor with anywhere near the peak power required for an on-road EV?


----------



## josmeijer (Apr 24, 2011)

EVfun said:


> But can you find a single phase AC motor with anywhere near the peak power required for an on-road EV?


single phase AC motors are no option.
They have near-to-none starting couple while using up to 30 times nominal amperage until at their top-speed.
You should use triphase motors that are dumped 100 a day by industry so can be found on any scrapyard is all (k) wattages and speeds.
Next thing is to convert DC to triphase AC.

Inverter motor controllers (also industry standard, and easily obtained on ebay etc at reasonable prices) can be fed by DC
simply multiply the input voltage with 2 sqrt (roughly 1,4) and you have the required voltage. 
So 110 v AC gives 162 DC volts.

Inverter motor controllers come in single-phase in / three-phase out that are rather popular.
They exist in up to 3 kw /220-240 volt in and >500 kw in threephase.

For more power you have to get three phase in/out types. These can be DC powered too, by paralleling the phases.
(first stage of any inverter controller rectifies the AC so phase is no issue, but you should check wit the manufacturer if this can be done without triggering some safety)

Yet the drawback is the high battery voltage but, as our soccer-idol Johan Cruyff says: "every disadvantage has it´s advantage" : you save many kilo´s of copper wiring and you might get a nice deal on small standard AGM batteries.

Finally,if you want to dig into it, most inverter controllers can do DC braking wich can be used to convert braking energy into battery power (instead of useless heat on your brakes).

But I must honestly say that all I state here remains theory for me.
I have lots of plans but all reside on paper until now.


----------



## Weenam (Feb 13, 2012)

A query I have is finding a source for a forklift motor. Other than purchasing a wrecked forklift I have seen information about picking them up from servicing and repair places. However if a motor is being thrown out then surely it is not going to be worth salvaging for using in an electric car conversion. If it won't work in a forklift any more then to me it follows that it is only suitable as scrap. Please any advice gratefully received.


----------



## Duncan (Dec 8, 2008)

Weenam said:


> A query I have is finding a source for a forklift motor. Other than purchasing a wrecked forklift I have seen information about picking them up from servicing and repair places. However if a motor is being thrown out then surely it is not going to be worth salvaging for using in an electric car conversion. If it won't work in a forklift any more then to me it follows that it is only suitable as scrap. Please any advice gratefully received.


Hi Weenam
Forklifts can live for a very long time - long enough to outlive their spare parts supply

There are lots of parts on a forklift from the batteries to the hydraulics to the controllers - any one of them dying on a ten year old machine can make it not economical to repair 
This results in a lot of forklifts being scrapped - the motors are still fine
Some of these are kept as spare parts - but forklift motors are robust - spares are not needed very often
So forklift motors become scrap metal

I got real lucky on mine, it had just been refurbished when the forklift was scrapped
$100 - its bigger than I would have chosen but more torque is good!


----------



## josmeijer (Apr 24, 2011)

It is not impossible that those firms find it more profitable to replace the motor with a new Chinese or salvaged motor.
Yet, in my opinion the best place to get it (and where I got mine) is from a firm that sells and maintains forklift trucks.
They usually take in the old when they sell a new one and the majority of these is wrecked.
I asked them to look out for one and I paid their time to disassemble it.


----------



## epyon (Mar 20, 2008)

*Finding a motor on a (cheap)budget*

The motor I got is off of a utilty cart that had a 9" inch Ford rear end an a GE motor . I took A2 an S1 and hook them together . I put A1 to pos an S2 to neg and ran forward ....great . A1 to neg an S2 to pos ... still forward , not good . What do I have to do to make the motor run backwards an forward for the cheap ? The motor really looks good in there with the driveshaft an cool looking motor mount I made , and I'm not rich .


----------



## josmeijer (Apr 24, 2011)

A1 and A2 are the rotor connections and S1 and S2 are the (serial) field connections.
So if you connect A1 to the battery and S1 to A2, it should run one way if you connect S2 to the other battery pole, and the other way with S2-A2 interconnected and S1 on the battery.
If that trick doesn't work, I fear there is some massive short cirquit in the field winding or in the wiring.


----------



## tropes (Jul 24, 2011)

*Re: Finding a motor on a (cheap)budget*



epyon said:


> The motor I got is off of a utilty cart that had a 9" inch Ford rear end an a GE motor . I took A2 an S1 and hook them together . I put A1 to pos an S2 to neg and ran forward ....great . A1 to neg an S2 to pos ... still forward , not good . What do I have to do to make the motor run backwards an forward for the cheap ? The motor really looks good in there with the driveshaft an cool looking motor mount I made , and I'm not rich .


CW- S1 to battery; S2 to A2; A1 to other battery terminal.
CCW- S1 to battery; S2 to A1; A2 to other battery terminal.


----------



## josmeijer (Apr 24, 2011)

*Re: Finding a motor on a (cheap)budget*



tropes said:


> CW- S1 to battery; S2 to A2; A1 to other battery terminal.
> CCW- S1 to battery; S2 to A1; A2 to other battery terminal.


if I´m not mistaking I said the same, , though phrased a little differently .

But after some close reading (wich I didn´t do the first time) I found that you changed the polarity of the battery and left the field alone.
So there is probably nothing wrong with the motor.
What you should do, is changing the polarity of the field, (swap S1 and S2) en never mind the polarity of the power source to change direction.


----------



## McRat (Jul 10, 2012)

Forklifts:

It is seldom the motor that retires a forklift for good, it's the battery + one other problem, often the transmission or hyd pump or circuit board. The battery is the most expensive part, often over $5k. I've never had a motor failure, but other issues.

I feel guiltly, but I have perhaps "given" away 3 forklifts in my life. Scrap value. 

Look on Craigslist, a busted electric forklift is often dirt cheap after you subtract the resale value of the battery. The batteries are often over 2000lb, mostly lead. Scrap batteries are 30 cents US a pound, so over $600, and the lift can be had for $500. What's the catch? A forklift weighs 4500+ lbs. You must pick it up in person.


----------



## josmeijer (Apr 24, 2011)

McRat said:


> Forklifts:
> 
> The battery is the most expensive part, often over $5k.
> (....)
> ...


You should get them in Holland, I pay 1,8k€ (roughly 1,4k$) for a 24v set of 700AH tubular batteries (and real good ones, I bought them in 2000 and they still have approx. 90% of their initial storage capacity by daily use).
So for a 48v forklift that would make 2,8k.

Batteries are seldom really dead. If you buy the forklift with batteries that need replacement you stilll would get a couple of miles out of them after thoroughly loading (and refilling with distilled water) so if you can get it anywhere in the neighbourhood you could still drive it to your garage if you´re lucky.
Nevertheless I would still recommend paying the firm that scraps the thing to unmount the motor at a reasonable price so you are not left with 4100 tons of scrap, and they can still sell it for roughly the same price so everybody happy.
I don´t now how regulations are in the US but here lead-acid batteries are virtually worthless, as nowadays they only accept empty ones that are cleaned from any trace of sulphuric acid and you have to dispose of that acid in a legal way so any profit on the lead is eveporated on advance.


----------



## tropes (Jul 24, 2011)

*Re: Finding a motor on a (cheap)budget*



josmeijer said:


> if I´m not mistaking I said the same, , though phrased a little differently.


series motor connection.


----------



## epyon (Mar 20, 2008)

I have a shifter that can shift two poles at a time (I want to keep it simple) . If I cant just switch neg an pos , how should I hook up this switch ? A2 switches or S1 ? Will A1 get pos and not get switched ? Can I just switch S1 an S2 between a pos an neg and then just let A1 stay pos an A2 stay neg ? Can the motor be sent to a motor shop an made to just run in series so I can just swap the poles ?


----------



## tropes (Jul 24, 2011)

epyon said:


> I have a shifter that can shift two poles at a time (I want to keep it simple) . If I cant just switch neg an pos , how should I hook up this switch ? A2 switches or S1 ? Will A1 get pos and not get switched ? Can I just switch S1 an S2 between a pos an neg and then just let A1 stay pos an A2 stay neg ? Can the motor be sent to a motor shop an made to just run in series so I can just swap the poles ?


Rich or poor, if you want reverse, I think you should invest in a controller that has reverse capability.


----------



## epyon (Mar 20, 2008)

It doesn't mater if it's the best controller money can buy , If I can not use the motor or hook it up right . I'll just go out side and check it after the sun goes down a little .


----------



## major (Apr 4, 2008)

tropes said:


> Rich or poor, if you want reverse, I think you should invest in a controller that has reverse capability.


With series motors reversing is accomplished with a contactor set not in the controller. Or some lower voltage/power systems like golf carts will use a manual multipole selector switch. Here is how it looks in the circuit:









Ref: from the Curtis manual.


----------



## tropes (Jul 24, 2011)

major said:


> With series motors reversing is accomplished with a contactor set not in the controller. Or some lower voltage/power systems like golf carts will use a manual multipole selector switch.


Thanks Major. Would you suggest using a contactor or manual switch without a controller?


----------



## major (Apr 4, 2008)

tropes said:


> Thanks Major. Would you suggest using a contactor or manual switch without a controller?


I don't understand the question. You need the controller for speed control. The reversing contactor (or switch) is outside the controller. The manual type of reversing devices may not hold up well with voltage in excess of 48 or with currents exceeding 200 amps regularly. And they are a PITA to string large cables to where you can reach them. Reversing contactor sets can be located near the motor and controller and activated with a signal switch. Contactors also come in higher voltage/current ratings.

I don't suggest running any motor (in an EV) without a controller.


----------



## epyon (Mar 20, 2008)

Controller was bad and I just needed to switch the S1 an S2 to get reverse , switch the field not the rotor . The utility cart the motor came from had a tool box with engines on it an could push a car every night . I seen it do that before he stop paying his taxes . It can go to the body shop now that I see the basic parts work .


----------



## Snakub (Sep 8, 2008)

Anyone ever use or thought about using a brushed dc elevator motor? Where could I find one?


----------



## Electric Forklift Guy (Dec 13, 2012)

Duncan said:


> Hi Weenam
> Forklifts can live for a very long time - long enough to outlive their spare parts supply
> 
> There are lots of parts on a forklift from the batteries to the hydraulics to the controllers - any one of them dying on a ten year old machine can make it not economical to repair
> ...



Yes , the large majority of electric forklifts that get scrapped have good motors and controllers in them

The main reasons electric forklifts get scrapped is usually from mechanical issues , or you have a "Receiving Manager" who refuses to believe you when you tell him the battery is bad.

Its rare to scrap one out for a bad motor or controller....we have a "rebuild industry" for these components and its not that expensive for us 

To give you an idea , I can get a Curtis 1244 controller for $150 dollars as long as I have a core to trade in.

And the GE EV-100 controller . the most expensive part on that to replace is the oscillator board ( $180)

My company used to have a 5 acre "junkyard' for forklifts and I can tell you that almost all of the electric trucks were DRIVEN into the yard.



Anyway , to get back onto the subject 

Even if the controller or the motor is bad you can still trade it in as a "core" to a rebuild company ( Like Flight Systems or M and M Motors ) for a rebuilt one and its a lot cheaper than buying a new one .


----------



## Electric Forklift Guy (Dec 13, 2012)

josmeijer said:


> A1 and A2 are the rotor connections and S1 and S2 are the (serial) field connections.
> So if you connect A1 to the battery and S1 to A2, it should run one way if you connect S2 to the other battery pole, and the other way with S2-A2 interconnected and S1 on the battery.
> If that trick doesn't work, I fear there is some massive short cirquit in the field winding or in the wiring.



In the jargon of electricians "S" is for "Stator"

Electronics technicians would label it "F" for "Field". 

I really wish electronic technicians and electricians could standardize symbols and names better

Im an industrial electrician so I have to deal with both sets and it irritates the hell out of me sometimes

Its almost like speaking two different languages that are distantly related, like Italian and Latin.


These two sentences mean exactly the same thing

" I need the in-line reactor in series with the stator"

" I need the induction coil in series with the field "

And it doesn't stop there

"E" is "V"

Snubber is a filter

"Lagging Power Factor" is "Negative Phase Angle"

" Contactor " is " Power Relay"

And I swear to God I feel like strangling the son of a bitch who came up with some of the electrical terms the computer nerds use.
( So now its Italian, Latin and Ebonics.)


----------



## major (Apr 4, 2008)

The industry standard for marking the terminals on DC motors used in forklifts, industrial utility vehicles and golf carts in the United States was and still is, I believe, as follows:

*A* for Armature (connected internally through the brushes),

*S* for Series field coils,

*F* for Shunt or Separately Excited field coils.


----------



## Hollie Maea (Dec 9, 2009)

Electric Forklift Guy said:


> These two sentences mean exactly the same thing
> 
> " I need the in-line reactor in series with the stator"
> 
> " I need the induction coil in series with the field "


They do NOT mean exactly the same reason, which is why you will always have both. "Stator" is a mechanical designation while "Field" is an electromagnetic designation. The "Field" is the source of magnetic flux (either a magnet or an electromagnet). The "Stator" is the stationary portion of an electric machine that surrounds the rotor. For brushed DC motors, the terms are often used interchangeably, because the Field resides in the Stator (in the case of series wound brushed DC motors, the field is an electromagnet, so the stator contains field windings. PM brushed DC motors have magnets in the Stator). But in other motors, such as 3 phase AC motors or brushless DC motors, the field resides in the rotor, and the stator contains the armature windings (which are in the rotor in a brushed DC motor).

So if you are working with more than one kind of motor, the distinction is very important, so those two terms aren't going anywhere.  Sorry it makes your life harder, but motors are complicated beasts.


----------



## major (Apr 4, 2008)

Snakub said:


> Anyone ever use or thought about using a brushed dc elevator motor? Where could I find one?


On the roof of tall buildings  I think elevator motors are large, high voltage and probably shunt wound making them a difficult fit for EV cars.


----------



## epyon (Mar 20, 2008)

major said:


> On the roof of tall buildings  I think elevator motors are large, high voltage and probably shunt wound making them a difficult fit for EV cars.


Warp 13 size or bigger ..... WARP 15 ???


----------



## Pbk (Jun 3, 2012)

I work for a large airline and when we scrap electric vehicles I assure all of you it's never because the motor is bad.
If its old the cost of new hoses fork blades paint seat tires brakes and the kicker a $5000 to $6000 battery is the reason to scrap.
Last month we sent 8 electric pickers to scrap because it was part of the city contract with the building, go figure! 
I have a 9 inch dc advance they threw away with under 100 hrs on it because someone didn't tighten the set screw on the shaft key ill just weld the adapter on or redo the shaft if i ever get a project.
Why toss a 1000 motor cause time is money and. Sending people far away and paying for hotels out costs parts. 
Fork lift motors are good also airport belt loaders and bag tugs if they are electric are good most of the belt loaders and bag tugs use dc advance 9 inch motors 
http://gsemarket.com/index.htm
Used stuff some times sells for less than scrap value on this site
It has to do with tax depreciating equipment to nothing being better than scrapping it without proff of 0 value 
Happy hunting


----------



## PaultheCluffy (May 23, 2013)

I am glad I live in Australia and have used the Metric system for over 40 years. I find it so easy to use, and find the avoirdupois methodology a fair bit harder. 
Is a 50kw motor big enough, 67,000HP to drive an electric car?


----------



## puddleglum (Oct 22, 2008)

PaultheCluffy said:


> Is a 50kw motor big enough, 67,000HP to drive an electric car?


That should be 67 HP not 67,000. I think you will need to supply more info to answer your question properly. Depending on many other factors, it might or might not be. 50kw is enough to move a small car, but a power number alone is not enough. Example, I have a forklift motor that is only rated for 10kw, but that is continuous at only 44 volts. It weighs over 100kg's and, if I up the voltage, it will move a car. Others have used the same motor successfully. On the other hand, there are RC motors that are rated for 20kw that you could hold in your hand. They might power an e-bike if you were lucky. See what I'm saying?


----------



## PaultheCluffy (May 23, 2013)

Thank you puddleglum for your answers. Yes I had made a big mistake with the HP. Don't normally use them so easy to mess up. I am thinking of using Nimh batteries, D cell 10Ah, about 5000 of them, as the power supply for my motor. I am thinking that Nimh or maybe Lithium Ion are the most power dense batteries that are around. And maybe having 2 50kw motors or a 50kw and a 20 kw.


----------



## VTwindRUSH1963 (Jul 7, 2013)

Hello All,

Delighted to find this portal and all the great info. So I'm planning on doing a EV, and have located a motor, and was looking for some advice before I purchase it on Ebay. It is in the $1,500 cost range. Is that a fair price for new unknown motor make/model?

See attached summary.

? is this acceptable for a EV converson? Have not decided on donor car yey, maybe VW cabriolet, small pick up, or Mazda Miata. Would really like to do convertable, maybe a jeep too. Trying to do this on a budget. Hoping for 50 mile range at minimum.

? Does anyone have a clue who makes this motor?

? Any suggestions for controllers.

? What bus voltage should i go with.

? Can i do some type or re-gen or is that too dificult with used/low cost controllers?

? Do i need tach or sensor on motor, i do not see a plug on the pictures.

? Should i go with transmission & cluch or direct to transmission, or straight to drive shaft if i go with non transaxle running gear.

Thanks for the help and advice.

Regards,

Trevor


----------



## major (Apr 4, 2008)

VTwindRUSH1963 said:


> Hello All,
> 
> Delighted to find this portal and all the great info. So I'm planning on doing a EV, and have located a motor, and was looking for some advice before I purchase it on Ebay. It is in the $1,500 cost range. Is that a fair price for new unknown motor make/model?


Not bad. A new one would probably be twice that. A similar sized used forklift motor might be found for less.


VTwindRUSH1963 said:


> See attached summary.


Interesting.


VTwindRUSH1963 said:


> ? is this acceptable for a EV converson?


Probably. It looks pretty nice IMO.


VTwindRUSH1963 said:


> Have not decided on donor car yey, maybe VW cabriolet, small pick up, or Mazda Miata. Would really like to do convertable, maybe a jeep too. Trying to do this on a budget. Hoping for 50 mile range at minimum.
> 
> ? Does anyone have a clue who makes this motor?


I don't think it was Prestolite like they suggest. 


VTwindRUSH1963 said:


> ? Any suggestions for controllers.


The usual big boys like Solitron, Zilla, Netgain.


VTwindRUSH1963 said:


> ? What bus voltage should i go with.


Using those controllers, any battery voltage up to limit (about 400) and then limit motor voltage to 150 to 200 depending on your need.


VTwindRUSH1963 said:


> ? Can i do some type or re-gen or is that too dificult with used/low cost controllers?


Not with a series motor.


VTwindRUSH1963 said:


> ? Do i need tach or sensor on motor, i do not see a plug on the pictures.


I suggest a speed sensor. I think all those controller will limit speed for you. And it is a nice parameter to monitor.


VTwindRUSH1963 said:


> ? Should i go with transmission & cluch or direct to transmission, or straight to drive shaft if i go with non transaxle running gear.


Up to you.


----------



## puddleglum (Oct 22, 2008)

VTwindRUSH1963 said:


> Hello All,
> 
> Delighted to find this portal and all the great info. So I'm planning on doing a EV, and have located a motor, and was looking for some advice before I purchase it on Ebay. It is in the $1,500 cost range. Is that a fair price for new unknown motor make/model?


If you are going to spend that much, why not just buy a Warp or Kostov for just a little more. They are already optimized for EV use, well proven and have a warranty. Just my opinion.


----------



## VTwindRUSH1963 (Jul 7, 2013)

puddleglum said:


> If you are going to spend that much, why not just buy a Warp or Kostov for just a little more. They are already optimized for EV use, well proven and have a warranty. Just my opinion.


Thanks, i was off on the price with shipping its 1100, and is new, so what does a warp or kostov cost? Are they ~25 HP cont? I guess i better do some more research before i pay for this unit.


----------



## puddleglum (Oct 22, 2008)

VTwindRUSH1963 said:


> Thanks, i was off on the price with shipping its 1100, and is new, so what does a warp or kostov cost? Are they ~25 HP cont? I guess i better do some more research before I pay for this unit.


$1100 shipped is a lot less than the $1500+ shipping you had posted before. Major is the motor expert, I'm NOT, but there are a few EV motors that claim 25 Hp cont. in the $1400-1800 range. I know for a fact that a new forklift motor is much more money than an EV motor of similar power and you still have to modify it. Used ones can be pretty cheap though.


----------



## Dustin_mud (May 22, 2012)

Whats a cheaper replacement if any for a larger Ac motor like the AC-76?


----------



## Archiv3r (Aug 11, 2014)

i would like someone to help me.
i came across this motor, and i am wondering could i use it in my ev.

price: 500$
15,2 kW, 236 A, 75 V
1800 rpm na 75 V and 2300 on 96V.

it is rated for 1800 so i dont know if this 2300 is okay to run on.

if i understood correctly, this motor would give me top speed of 60kmh.(around that)

or should i put in another 500$ and take kostov 9"

help me plox


----------



## major (Apr 4, 2008)

Archiv3r said:


> i would like someone to help me.
> i came across this motor, and i am wondering could i use it in my ev.
> 
> price: 500$
> ...


Please post some photos and/or more details. Where did those numbers come from? Can you post the source? What kind of motor is it?


----------



## Archiv3r (Aug 11, 2014)

its a dc motor, series wound
http://prntscr.com/4cv9y1
http://prntscr.com/4cvab5
http://prntscr.com/4cvaqf
http://prntscr.com/4cvb1f
http://prntscr.com/4cvbjj


----------



## major (Apr 4, 2008)

Nice motor. Looks like robust construction. However it was likely used to drive a pump and therefore has a shaft which will be a bitch for you to use. Also the power rating is for S3 duty cycle of 33%, so the continuous or one hour rating will probably be one third to one half of that figure or 5 to 7kW at 72V. Raising voltage and RPM can increase the rating if good ventilation is provided. Enough for your car? Depends on the car and expected performance (speed, hill climb, payload, etc.).


----------



## Archiv3r (Aug 11, 2014)

major said:


> Nice motor. Looks like robust construction. However it was likely used to drive a pump and therefore has a shaft which will be a bitch for you to use. Also the power rating is for S3 duty cycle of 33%, so the continuous or one hour rating will probably be one third to one half of that figure or 5 to 7kW at 72V. Raising voltage and RPM can increase the rating if good ventilation is provided. Enough for your car? Depends on the car and expected performance (speed, hill climb, payload, etc.).


thank you for your reply.
How do you know its S3? (just curious, so i know in the future)
what is downside of raising rated voltage and rpm besides higher temperature and therefore better ventilation needed?
i thought of driving ev in straight terrain (no hills or anything like that), with a top speed around 80-ish kmh, this probably wont do above 50-60 kmh the more i look. correct?


----------



## major (Apr 4, 2008)

Archiv3r said:


> How do you know its S3?


I can see it on the nameplate. And higher voltage can sometimes cause arcing on the brushes to commutator.


----------



## frank lamonte (May 14, 2015)

Newbe here what about a splined shaft clark forklift motor 36/48volt motor on ebay? is that a good candidate for a useable motor? Thank for any help......frank l.


----------



## morganharri (Jul 8, 2015)

I have 36v motor which i have purchased 2 years ago and it is really working very well.


----------



## tenthousandclowns (Jun 21, 2012)

what do you think of this salvage AC motor?
http://www.ebay.com/itm/AZURE-DYNAM...376728?hash=item1ea9002098:g:ioMAAOSwYaFWfE0u

3 phase
25hp
1785 RPM
208v
$500 OBO

what if it was run at 144v instead of 208v, with a curtis 1238?


----------



## dcb (Dec 5, 2009)

tenthousandclowns said:


> what do you think of this salvage AC motor?
> http://www.ebay.com/itm/AZURE-DYNAM...376728?hash=item1ea9002098:g:ioMAAOSwYaFWfE0u
> 
> 3 phase
> ...


you have to go into the wayback machine to find the datasheet for that one:
http://web.archive.org/web/20090806...-drive/documents/AC90_DMOC645ProductSheet.pdf

but 208v is rms, which is really more like 294v dc pack, the datasheet says 312v min.

so look at the first graph, and slide it to the left by 144/312. So that the knee is at ~623 rpm.

Also the curtis is probably a 500 amp controller, so then pull the whole graph down by 500/600.

so the knee will be at about 416 ft lbs (graph is in nm fyi), which puts you at about 50 hp (37kw) at 623 rpm. 

with the dmoc and a 312v pack it says it does 97kw at 1500 rpm. but the thing weighs 189kg! 

Plus 3 phase controller costs are not cheap. Even with a kit expect lots of time and several hundreds of dollars.

edit: I'm at a bit of a loss as to how a 312v pack and a 600 amp controller is only making 100kw.
edit2: must be a sqrt(2) * efficiency thing.


----------



## tenthousandclowns (Jun 21, 2012)

mmm..
I really don't know anything about AC motors... maybe I'll stick with DC for now.


----------



## dcb (Dec 5, 2009)

I hear ya, I keep an eye out for a nice DC motor too, but damn these induction motors are cheap ( I have a 4 pole 7.5hp 1765rpm for $100 on the bench that looks about like an ac51 on paper, with 1.4x longer windings, and of course no testing in that sort of environment or hundreds/thousands/??? of satisfied customers), but then the extra requirements start kicking in. It isn't too bad as hobbies go though, keep ya busy for a while


----------



## bigmouse (Sep 28, 2008)

Those look like nice motors, but the max speed is a bit low and the rated voltage is a bit high. From what I can tell, these were installed in-line with the driveshaft on the hybrid trucks/vans/busses that they came from, so 5000rpm is probably plenty for that. A rebuild of one of these with a high speed balance and some good bearings would probably make for a very nice motor. I can't tell if they're water cooled or air cooled. It looks like there might be a hose poking out in one of the photos?

A repurposed Prius inverter with either my control board in it, or two of Eldis's boards in it make AC motors more feasible for DIY, though not plug-and-play like the DC stuff.


----------



## major (Apr 4, 2008)

bigmouse said:


> Those look like nice motors, but the max speed is a bit low and the rated voltage is a bit high. From what I can tell, these were installed in-line with the driveshaft on the hybrid trucks/vans/busses that they came from, so 5000rpm is probably plenty for that. A rebuild of one of these with a high speed balance and some good bearings would probably make for a very nice motor. I can't tell if they're water cooled or air cooled. It looks like there might be a hose poking out in one of the photos?


Hi big,

Those were made by Lincoln Electric in Cleveland; a NEMA 286T frame. We used one for a project and balanced the rotor and used precision oil lubed bearings and did well over 10,000 RPM, 12k peaks. With modified windings, 350Vdc bus and liquid cooling, it was capable of over 200kW. Those pictured are TENC (totally enclosed non-cooled). And I think the Azure application was limited to like 400A-phase (for member dcb).

Those are real nice motors--- big but nice. Great extruded aluminum frame shell. A shame they used iron end caps. We had aluminum ends made for ours.

Regards,

major


----------



## tenthousandclowns (Jun 21, 2012)

Ok... why are these ones so cheap?

http://www.ebay.com/itm/Force-Drive...015043?hash=item41a9956743:g:SwAAAOSwv9hW2JFv

AC24LS motor
88.2 lbs
15kw continuous at 4k rpm
35 kw peak

"peak efficiency 85%" isn't that kind of low?

$150 OBO


----------



## dcb (Dec 5, 2009)

they have a weird output shaft, not insurmountable though, plus you may need a real drive end bearing. And the seller has zero feedback.

Also most folks are looking at scrap tesla motors, etc, these days, spurred on by a desire for more power if you are going to go through all the effort.

I'm sure there is a niche for these, but 3 phase controller (and battery) costs make it worth investing a little bit more in the motor if it means you will get more out of the rest of your investment.

edit: a pic of the dataplate would help, also folks may want liquid cooled, I'm looking at ODP motors myself. This is TENV, enclosed no fan (can add one maybe), not the best for continuous power.


----------



## rahulkentonn (May 15, 2016)

Toyota 4Y engine is the best option. I have heard it is widely available and it is very reasonably priced !


----------



## Jbrewer106 (May 7, 2015)

major, can you decribe how you modified the windings?



major said:


> bigmouse said:
> 
> 
> > Those look like nice motors, but the max speed is a bit low and the rated voltage is a bit high. From what I can tell, these were installed in-line with the driveshaft on the hybrid trucks/vans/busses that they came from, so 5000rpm is probably plenty for that. A rebuild of one of these with a high speed balance and some good bearings would probably make for a very nice motor. I can't tell if they're water cooled or air cooled. It looks like there might be a hose poking out in one of the photos?
> ...


----------



## major (Apr 4, 2008)

Jbrewer106 said:


> major, can you decribe how you modified the windings?


Basically same or slightly increased copper mass (slot fill) with less turns and increased (effective) conductor cross sectional area. ie. Decrease V/f, increased base frequency.


----------



## ATFforklifts (Jul 13, 2016)

sukusia said:


> So here is what I learned about motors from this site. I wanted to post a quick reference so newbs (like myself) do not have to sort through the sticky page.
> 
> *When looking for a forklift motor:*
> Get a series wound motor because they have very high torque and handle abuse (over volting) a lot better.
> ...


Good job! U seems a master of forklifts..


----------



## Mane55 (Jan 22, 2018)

sukusia said:


> Good thing I'm not in Europe then.


I am very happy to live in Europe. All calculations are way easier using metric units. You also may check your formula simply checking that the units match. 
A few examples:
F=ma so 1N = 1kg * 1m/s^2
P=Fv so 1W=1N * 1m/s = 1 kg * 1m^2 / s^3 
And also P=I*U so 1W=1A*1V
Luckily seconds, amperes and volts are the same here and there.
For energy
1J=1Ws and thus 1kWh=1000W * 3600s=3 600 000 J = 3.6 MJ


----------



## Karsten (Jun 11, 2018)

Hi.
Would be nice to get some input on using this Fanuc 10 M dc servo motor to power a light weight Opel Corsa. Theyt apparently have high torque since they are used in Cnc lathes etc. The motor is about 30 years old but was never used.

Any advice would be appriciated.
Thank you.


----------



## major (Apr 4, 2008)

Karsten said:


> Hi.
> Would be nice to get some input on using this Fanuc 10 M dc servo motor to power a light weight Opel Corsa. Theyt apparently have high torque since they are used in Cnc lathes etc. The motor is about 30 years old but was never used.
> 
> Any advice would be appriciated.
> ...


165V * 12A = 1980W or about 2 hp by the time you get to the shaft output. 

I doubt you'll be happy with a 2 hp powerplant in a car.

Regards,

major


----------



## Electric Forklift Guy (Dec 13, 2012)

Mane55 said:


> I am very happy to live in Europe. All calculations are way easier using metric units. You also may check your formula simply checking that the units match.
> A few examples:
> F=ma so 1N = 1kg * 1m/s^2
> P=Fv so 1W=1N * 1m/s = 1 kg * 1m^2 / s^3
> ...



Uh , electric units are metric.
Electricians usually do all the calculations in metric to get Watts and Newton Meters and just hit the old conversion button so "Non-Electricians" can understand what we are talking about.

But every American electrician knows that 1 Electric horsepower is 746 watts.

It's actually a myth that Americans dont know what the metric system is , we are taught it in school , and if we go into any field of science or engineering we use it almost exclusively.

Every mechanic knows that 1/2 inch is 12.7 mm and that if they have a 13 mm bolt head thats stripped a 1/2 inch wrench will grip it a little tighter.

Everyone who changed the oil in a car knows that a liter is almost 6% larger than a quart.

Some products are sold in metric values ( like a 2 liter soda bottle )

Every car enthusiast knows that 100 km/h = 62 MPH

Everyone knows that a meter is 3 and 3/8 inches longer than a yard and a kilogram is 2.2 pounds.

American understand the metric system , we just prefer using the traditional measurements in our daily lives.


----------



## Emyr (Oct 27, 2016)

What's the conversion between CI and litres?


----------



## Hirngespinste (Jul 26, 2018)

Electric Forklift Guy said:


> American understand the metric system , we just prefer using the traditional measurements in our daily lives.












Sure... "traditional" is the best


----------



## Duncan (Dec 8, 2008)

"Traditional" is not too bad for simple stuff

But it's truly awful if you have to do anything remotely complicated!


----------



## TheFallen018 (Jul 28, 2018)

Hey guys, I couldn't quite find this info in the thread, so maybe someone would know. 

I'm looking to buy a 3 phase induction motor with a rated power of about 90-100kw. I haven't been able to find many motors that fit this description. Would anyone know of a good place to buy motors like this?

Also, are there any recommendations on things to look for in these motors? 

Thanks.


----------



## Duncan (Dec 8, 2008)

Hi
An industrial motor at 90 -100Kw will be HUGE - 300Kg or more 

About the only source of AC motors of that sort of power level and a decent weight is Electric Cars

The motor from a crashed Nissan Leaf or something


----------



## alfamuppet (Jun 8, 2016)

TheFallen018 said:


> Hey guys, I couldn't quite find this info in the thread, so maybe someone would know.
> 
> I'm looking to buy a 3 phase induction motor with a rated power of about 90-100kw. I haven't been able to find many motors that fit this description. Would anyone know of a good place to buy motors like this?
> 
> ...



Peak power maybe 100kW is what you require unless you are converting a coach... most ev motors except pm (permanent magnet) are rated at their 100% duty cycle, hence 15kW to 25kW tops ... then they are over driven to usually 5 times their name plate power to get 100kW (not continuously). PM motors cannot be over driven otherwise the heat destroys the magnets.


E.g. Advanced FB4001 27Hp continuous, 100Hp peak ( 20.146kW continuous and 74.6kW peak for our metric friends).


The cheapest option is a secondhand DC motor made for EV's or the ac route is an Enova or Brusa secondhand or a 18.5kW to 20kW 4 pole ac induction motor re wound to 100 to 150 volts (see you motor winding specialist or the You Tube videos on rewinding it yourself if you want it for bottom dollar). Tesla motors are ac and could be cheap as they are a bit too exotic, but there are parts for them to run on this very forum.


----------



## knoxsp (Aug 8, 2018)

Would a motor from a mitsubishi outlander phev be suitable for a conversion? The specs say the rear motor has 95hp. These are comparatively cheap on ebay, but i can't find an example on this forum of one being used, which suggests they may not be a goer.
Any help is appreciated!


----------



## fj1289 (Oct 3, 2018)

Hirngespinste said:


> Sure... "traditional" is the best


new guy smart comment - but it was good enough to put man on the moon and bring him back again!


Now back to learning about this EV stuff!


----------



## Emyr (Oct 27, 2016)

fj1289 said:


> new guy smart comment - but it was good enough to put man on the moon and bring him back again!


The scientists used SI units but the vehicles were made by traditional US aero shops, using imperial units.

The guidance computer used "metric" SI units internally, but converted inputs from imperial and converted SI to imperial for displays.

See paragraph just after figure 4.
https://www.doneyles.com/LM/Tales.html


----------



## jbman (Oct 26, 2017)

Hey folks,

I'd like your opinion on a motor. They included several pictures, so I'm trying to make sure I know what to look for on this motor or a different one in the future.

https://www.ebay.com/itm/273503659982

The commutator appears darkened, but is it "scorched"? What does an appropriate film look like?
I see four terminals, but is this motor sepex or series?
There are two sets of plugs on the sides - would those be a temperature switch and thermistor, perhaps?
The bearing at the front is not sealed. I'm not sure if a seal goes over the top of it like on a pinion or wheel bearing; is this a concern?
Is the overall condition of this motor too poor?
Additionally, it's pretty pricey - I've struggled to find good prices on forklift motors locally or even on eBay, so I'm doing what I can.

Thanks a lot! I'm trying to scout out a motor for my CJ7 conversion that I'm planning.


----------



## MattsAwesomeStuff (Aug 10, 2017)

> I'd like your opinion on a motor.


My opinion is that they're charging 4x what it's worth.

Go to, or call up a local forklift repair yard and ask for old DC motors they may have sitting around. You'll get something better for closer to $200.


----------



## Duncan (Dec 8, 2008)

MattsAwesomeStuff said:


> My opinion is that they're charging 4x what it's worth.
> 
> Go to, or call up a local forklift repair yard and ask for old DC motors they may have sitting around. You'll get something better for closer to $200.


I sort of agree BUT - it's not as simple as that!
I finally tracked down our local elephant's graveyard - but it was not easy or fast


----------



## jbman (Oct 26, 2017)

MattsAwesomeStuff said:


> My opinion is that they're charging 4x what it's worth.
> 
> Go to, or call up a local forklift repair yard and ask for old DC motors they may have sitting around. You'll get something better for closer to $200.


I have been struggling to find a forklift yard locally. That's the only reason I'm looking online. I'll keep checking, and I agree the price is high. Just trying to get a better idea. Thanks!

Sent from my SM-N960U using Tapatalk


----------



## Duncan (Dec 8, 2008)

jbman said:


> I have been struggling to find a forklift yard locally. That's the only reason I'm looking online. I'll keep checking, and I agree the price is high. Just trying to get a better idea. Thanks!
> 
> Sent from my SM-N960U using Tapatalk


Hi
the way I found mine was by asking at a furniture place that had an electric forklift who looked after it!

You want "industrial concerns" that require cleanliness - so no exhaust soot from their forklifts


----------



## MattsAwesomeStuff (Aug 10, 2017)

> I have been struggling to find a forklift yard locally.


Dunno if you wanna say where you are, but... the thing about forklifts is literally everywhere in the industrial world has to have a place that services them in just about every city over 50,000. Everyone needs forklifts, everyone needs a place to fix them.

I have a sweetheart deal with mine. They'll move a forklift up on jackstands for me, outside the gate, and I can come help myself to it at night over a week or two, gutting what I want off it. And they don't charge me for anything I take. And I can occasionally borrow tools when there's something I don't have big enough tools to tear up. And they leave me deserts sometimes. The tradeoff is I show them pictures of what I'm working on.


----------



## jbman (Oct 26, 2017)

MattsAwesomeStuff said:


> Dunno if you wanna say where you are, but... the thing about forklifts is literally everywhere in the industrial world has to have a place that services them in just about every city over 50,000. Everyone needs forklifts, everyone needs a place to fix them.


That's the realization I came to after reading some more. I looked up repair shops instead of salvage yards, and I found a few local ones and sent out some messages. I'm in Colorado Springs.

Sent from my SM-N960U using Tapatalk


----------



## MattsAwesomeStuff (Aug 10, 2017)

> I looked up repair shops instead of salvage yards, and I found a few local ones and sent out some messages.


Bingo.

There aren't really any boneyards for forklifts because it's all proprietary shit and not worth fixing.

But guys who repair them will often buy clunkers for their batteries, because the most common servicing issue is some old piece of shit that was deep discharged too much needing new batteries and they can only afford $3k, not $40k.

Also, service lights and cracked dashes and stuff. Contactors, power cables. Foot-sized Anderson connectors, fuses, all get stripped out. The rest usually sold or given to some lower tier scrapper who'll haul it away for free, use the steel salvage to break even on gas money, and strip out the copper and aluminum to make it worth their time.

Unless a place services the same make and model of motor repeatedly (big cities), they won't bother to use shelfspace for them. They'll have a few "just in case" in the back, from a decade ago when they thought they might actually use them, and some pump motors that they might actually put into lifts once in a while, but not be attached to any of them. If they can get salvage price for them, that's probably more than they were getting from their scrapper.


----------



## Duncan (Dec 8, 2008)

The mast and forks are worth something in an agricultural area - you can attach them to the back of a tractor for a useful forklift thing


----------



## boekel (Nov 10, 2010)

I've had luck lately with 5 motors coming off a hydraulic project they changed specs. someone found them on our local craigslist.

24cm diameter (9,5 inch?)
10kW (S2 30 minutes)
48V

only downside so far is I need to bring out two extra poles, as they are built for one direction (had hydraulic pumps)

B2/3(?) flange

so that is worth a look also, hydraulic companies / adds for DC motors
I always keep some search tabs open in my browser for these kind of deals.


----------



## major (Apr 4, 2008)

That is what a commutator and film (or patina) should look like.










Beautiful motors boekel.

major

{edit} sorry. I'll try to resize on my laptop later.


----------



## J_D (Feb 17, 2019)

Hi, I'm a complete newb on here, and I'm planning a future Mazda RX8 DC conversion using used parts and new lead batteries.

Could you advise me what voltage forklift motor I would require please?

I want something to match 200hp, the RX8 weights 1400kg and need to reach 70mph.

Thanks for your help

Jon

Sent from my F8331 using Tapatalk


----------



## johnsiddle (Jun 22, 2011)

Hi Guy's

Do you think a hydraulic motor from a Lansing Bagnal Forklift rated at 67v and with the part number 4005679, Series wound continuous, would be a suitable EV drive motor?

regards John


----------



## major (Apr 4, 2008)

johnsiddle said:


> Hi Guy's
> 
> Do you think a hydraulic motor from a Lansing Bagnal Forklift rated at 67v and with the part number 4005679, Series wound continuous, would be a suitable EV drive motor?
> 
> regards John


Hi John,

I assume you mean a pump drive motor. Hydraulic motor typically refers to a device using hydraulic fluid flow to produce a mechanical output.

Contrary to what was told you on the other thread, main (lift) pump motors from fork trucks can be as powerful, or even more so, than traction motors. It depends on the type of lift truck. Just because the pump motor is rated on a low time-on duty cycle doesn't mean it won't run continuously, at a lower power output. And they are often fan cooled. 

The pump motor from a forklift may be suitable for an EV conversion. Typically they are unidirectional, so be sure rotation direction is correct for you. Switching rotation requires internal modification. And typically the motor will have an internal splined shaft making a coupling for a car very difficult.

Regards,

major


----------



## johnsiddle (Jun 22, 2011)

major said:


> Hi John,
> 
> I assume you mean a pump drive motor. Hydraulic motor typically refers to a device using hydraulic fluid flow to produce a mechanical output.
> 
> ...


Thanks Major.
The one I am looking at is on Ebay now, it is rated as continuous and has plenty of cooling from the picture it seems to have a fan and an open cover over the brushes, it still has the pump attached so presumably I could use parts of the pump to fabricate a flange of some sort, maybe weld a plate into it...
john


----------



## johnsiddle (Jun 22, 2011)

I have picked up a Pump Drive motor from a forklift it isn't the one I was hoping to get but hopefully it will be suitable.
It has a female star shaft but I have the star bush that was fitted to a keyed taper shaft on the pump assy and I hope to fabricate a shaft with it.

Also it does not have a fan fitted but I am sure I could force some air in thro the brush guard, getting the hot air out again might be a problem tho.

It measures 11in by about 8in diameter and has a good clean commutator with four sets of twin brushes.
Rated at 67V and 115Amps but only at 15min.

There are three 8mm female connectors coming through the body which are marked A, YY and Y, I understand the A means armature ( I guess) but does anyone know what the YY and Y mean they have continuity to A connected internally. The guy I got them from said it was for forward and reverse.

Anyone know for sure what the connections mean and could it be a suitable EV motor.

John


----------



## major (Apr 4, 2008)

Hi john,

From that info, I'd say it is a split field reversible series wound motor. The typical reversible series wound motor has 4 terminals, A1 & A2 for armature and S1 & S2 for the series field. Reversing is accomplished by reversing one or the other, but not both. This requires heavy (full motor current rated) contactors, two spdt. Read expensive.

The split series motor is actually designed and built with two independent (electrically) field coil sets. One coil set (Y) for one direction of rotation and the other coil set (YY) for opposite rotation. Now it can use a single spdt contactor or two spst. It does require additional diodes. This can be a cost savings. However you pay a penalty in series field resistive loss, perhaps affecting motor efficiency ~5%.

There are some other tricks designers can employ with the split series motor which can eliminate the reversing contactors altogether, do field weakening, and/or motor braking even with some degree of regeneration, when mated with a specialized controller.

Testing is the easiest method to verify what you have. Use a 12V car battery and jumper cables or the like. Put motor on floor or otherwise clamp it so it does not twist off the bench onto your toe. Connect one battery terminal to A. Connect (touch) the other battery terminal to Y. Note rotation direction. Leave A connected the same. Now touch other battery terminal cable to YY. If rotation is opposite, it is split series.

If rotation is the same, likely it is a tapped field. See if you can detect a difference in speed between the two connections.

Regards,

major


----------



## J_D (Feb 17, 2019)

Hi Could somebody help me please?

Could someone tell me what voltage DC motor I would need to propel a 1400kg car to 70mph and the explanation behind it please too.


Thanks 


Jon

Sent from my F8331 using Tapatalk


----------



## johnsiddle (Jun 22, 2011)

major said:


> Hi john,
> 
> From that info, I'd say it is a split field reversible series wound motor. The typical reversible series wound motor has 4 terminals, A1 & A2 for armature and S1 & S2 for the series field. Reversing is accomplished by reversing one or the other, but not both. This requires heavy (full motor current rated) contactors, two spdt. Read expensive.
> 
> ...


Thanks Major.
I have just checked and the main drive appears to be between A and Y. I can run between A and YY but it does go much slower PLUS I noticed that the connector for YY is only 6mm unlike the other two being 8mm.

Its strange it will run Y to YY albeit slow and A to YY still slow, but that might just be residual magnetism in the armature I guess in the Y/YY config.
It always runs the same direction.
Also it runs the correct direction for my gearbox (CW looking from the brushes end) so that is good.

I also put 50v on A/Y it and it sure took off, I am thinking when I get things running I will see how it runs using just 125V instead of the 174V I have available.

What are your thoughts generally about the suitability of this motor?

John


----------



## kennybobby (Aug 10, 2012)

*fissiks*



J_D said:


> Hi Could somebody help me please?
> 
> Could someone tell me what voltage DC motor I would need to propel a 1400kg car to 70mph and the explanation behind it please too.
> 
> ...




How quickly do you need to accelerate up to the 70 mph, e.g. 0 to 70 in xx seconds? For a rough estimate this determines the power rating of your motor.

So first i'm gonna convert some units; 1400 kg is about 3100 lbs, divide this Weight by gravity, g, to get mass, m; and 70 mph is a velocity, v, of about 103 ft/sec.

Now the kinetic energy of motion at 70 mph is (.5mv^2) = 510682 lb-ft

For a first order power estimate take the kinetic energy divided by your acceleration time, let's assume 0 to 70 in 13 seconds.

This gives a power of 39283 lb-ft/sec, a horse can pull 550 pounds over a distance of one foot in one second, so divide by 550 to get about 72 horsepower required for acceleration.

Your specific question of motor DC voltage can not be answered without additional information, such as the size of your battery energy storage system available to supply power for your vehicle. The voltage and current rating of your battery pack is the deciding and/or limiting factor for the motor selection. But we can take a look at some variables involved.

72 hp multiplied by 746 gives you power in Watts, about 54000 W. 

Now this power can be supplied as Volts times Amps = 54000.

If you have 1000 Amps available, then you only need 54 Volts, or
if you have 500 Amps available, then you only need 108 Volts, or
if you have 400 Amps available, then you only need 135 Volts, or ....etc.

See how this is going? there is no unique voltage solution until you select the limits for your acceleration time and your battery pack current. Then you can determine how many cells you need to make the voltage necessary, and then you can specify the motor winding voltage rating for the peak power that you need.


----------



## J_D (Feb 17, 2019)

Wow, you must be a professor or something [emoji4], thanks so much for your post, it does actually make alot of sense in the way you've written it.

I'd like to propel the car to 60 in 6 seconds, with a top speed of 70mph.

I will have to get back to you about the batteries as I'll be using lead acid batteries as these are being provided free to me, until I can afford lithium.

I will provide the exact battery details and weights as soon as I am at work, hopefully you'll be able to tell me roughly If they need to be connected in parallel or series.

Thanks so much for your help I really appreciate it [emoji4]

Sent from my F8331 using Tapatalk


----------



## kennybobby (Aug 10, 2012)

No, i'm just a ******* with a libary card...


----------



## J_D (Feb 17, 2019)

[emoji1787]

Sent from my F8331 using Tapatalk


----------



## Emyr (Oct 27, 2016)

*Re: fissiks*



kennybobby said:


> So first i'm gonna convert some units; 1400 kg is about 3100 lbs, divide this Weight by gravity, g, to get mass, m; and 70 mph is a velocity, v, of about 103 ft/sec.
> 
> Now the kinetic energy of motion at 70 mph is (.5mv^2) = 510682 lb-ft
> 
> ...


kinetic energy is measured in joules. lb-ft is a measure or torque, not energy.

Learn SI units, it makes the calculations a lot simpler.


----------



## brian_ (Feb 7, 2017)

*units of measure*



kennybobby said:


> ... Now the kinetic energy of motion at 70 mph is (.5mv^2) = 510682 lb-ft...





Emyr said:


> kinetic energy is measured in joules. lb-ft is a measure or torque, not energy.


In any system of units, the product of force and distance can be torque (moment of force), or energy, depending on context. For instance, in SI the units of torque are N⋅m, while the unit of energy is kg⋅m2/s2, or joule... which is also N⋅m. To keep these straight, the usual convention in the old units is to put the force unit first for torque (lb-ft), and the distance unit first for energy (ft-lb), so arguably kennybobby should have used ft-lb... but I don't think there's a consistent rule. Certainly in this context it is clear that the quantity is energy.



kennybobby said:


> For a first order power estimate take the kinetic energy divided by your acceleration time, let's assume 0 to 70 in 13 seconds.
> 
> This gives a power of 39283 lb-ft/sec, a horse can pull 550 pounds over a distance of one foot in one second, so divide by 550 to get about 72 horsepower required for acceleration.


The fact that ft-lb is a unit of energy is demonstrated as kennybobby continued to show that the rate of change of energy is power... including that a "horsepower" is defined as 550 lb-ft/sec (just as a watt is a J/s or N⋅m/s or kg⋅m2/s3



Emyr said:


> Learn SI units, it makes the calculations a lot simpler.


Yes, that avoids the unit conversion constants, but the physics is the same regardless of the system of units.


----------



## J_D (Feb 17, 2019)

*Re: fissiks*



kennybobby said:


> How quickly do you need to accelerate up to the 70 mph, e.g. 0 to 70 in xx seconds? For a rough estimate this determines the power rating of your motor.
> 
> So first i'm gonna convert some units; 1400 kg is about 3100 lbs, divide this Weight by gravity, g, to get mass, m; and 70 mph is a velocity, v, of about 103 ft/sec.
> 
> ...


Hi Kenny

Right, I have 4x 12v 50ah battery's and 2x 12v 26ah battery's , would this suffice? 

I may be able to get hold of some more, and what motor voltage would you recommend?

Thanks again

Sent from my F8331 using Tapatalk


----------



## jbman (Oct 26, 2017)

*Re: fissiks*



J_D said:


> Hi Kenny
> 
> Right, I have 4x 12v 50ah battery's and 2x 12v 26ah battery's , would this suffice?
> 
> ...


That's only going to get you 72 volts, and you are limited to the capacity of the 26ah batteries. Charging would be really awkward, too. You will need to match the capacity of your batteries. Those batteries would store about 3kwh, and you can only use a fraction of that as they are lead acid batteries. 

You may want to reconsider your battery choice. 72v could potentially be the bare minimum, but most systems run at least twice that. It will not get you to your performance goal, especially when you factor in the weight of the batteries.

Sent from my SM-N960U using Tapatalk


----------



## J_D (Feb 17, 2019)

*Re: fissiks*



jbman said:


> That's only going to get you 72 volts, and you are limited to the capacity of the 26ah batteries. Charging would be really awkward, too. You will need to match the capacity of your batteries. Those batteries would store about 3kwh, and you can only use a fraction of that as they are lead acid batteries.
> 
> You may want to reconsider your battery choice. 72v could potentially be the bare minimum, but most systems run at least twice that. It will not get you to your performance goal, especially when you factor in the weight of the batteries.
> 
> Sent from my SM-N960U using Tapatalk


Thanks for your reply

So how about if I could double the amount of batteries I had, would that work? (ps could potentially not use the smaller 26ah batteries and upgrade to the 50ah instead)

Sent from my F8331 using Tapatalk


----------



## kennybobby (Aug 10, 2012)

*An Intuitive Approach to Fissiks and Mechanics*

Take a look at your Craftsman torque wrench and see the units of torque: ft-lbs. 

Every mechanic knows what a 5 lb sledge hammer feels like in the hand, but who has an intuitive feel for 15 Newtons?

So take a ratchet wrench that's 12 inches (1 ft) long and pull the handle with 5 or 10 or 50 lbs--that's gonna be 5,10 and 50 ft-lbs of torque.

How many mechanics have a 1 meter long ratchet in their toolbox? and what's the 15 N pull force feel like to generate 15 m-N of torque?

So here is my intuitive reason why the correct units for torque is ft-lbs or m-N.

Torque is a vector cross product defined as R x F = |R|*|F|*sin(theta).
Reference: https://en.wikipedia.org/wiki/Torque

The equation for Work (Work is equal to the change in kinetic energy), which is a vector dot product or scalar with the units of energy.
Work = F . L = |F|*|L|*cos(theta)
Reference: https://en.wikipedia.org/wiki/Work_(physics)#Mathematical_calculation
https://en.wikipedia.org/wiki/Work_(physics)#Work–energy_principle

Both torque and work appear to have similar units, but confusion can be avoided by following the order of the vector equations: ft-lb for torque and lb-ft for work or energy.

Or in metric units: m-N for torque, and N-m for work or energy (N-m is Joules in SI units).


----------



## brian_ (Feb 7, 2017)

*Re: An Intuitive Approach to Fissiks and Mechanics*



kennybobby said:


> Every mechanic knows what a 5 lb sledge hammer feels like in the hand, but who has an intuitive feel for 15 Newtons?


15 newtons is the weight of 1.5 kg. That's far more familiar than "5 lb" for most people in the world outside of the U.S. Neither system is inherently easier; for each person, one system is more familiar.



kennybobby said:


> How many mechanics have a 1 meter long ratchet in their toolbox?


Probably not many, unless they work on heavy equipment. On the other hand, doesn't everyone have a breaker bar about a metre long? I do.


----------



## J_D (Feb 17, 2019)

So If I have 8x 12v 50ah , what would that give me?

Also What motor would be best suited to the battery capacity I have? 

And would it help me achieve my 1400kg car goal of 70mph?

With a range of 30miles? 

Sent from my F8331 using Tapatalk


----------



## jbman (Oct 26, 2017)

*Re: An Intuitive Approach to Fissiks and Mechanics*



brian_ said:


> 15 newtons is the weight of 1.5 kg. That's far more familiar than "5 lb" for most people in the world outside of the U.S. Neither system is inherently easier; for each person, one system is more familiar.
> 
> 
> Probably not many, unless they work on heavy equipment. On the other hand, doesn't everyone have a breaker bar about a metre long? I do.


This conversation is probably better had elsewhere, as it's not very strongly related to finding a good motor.

Sent from my SM-N960U using Tapatalk


----------



## jbman (Oct 26, 2017)

J_D said:


> So If I have 8x 12v 50ah , what would that give me?
> 
> Also What motor would be best suited to the battery capacity I have?
> 
> ...


To find the capacity of your battery pack, multiply the voltage by the amp hours. In your case, those batteries in series would get you to 96 volts. Multiply that by 50 amp hours and you get 4800 watt hours, or 4.8 kilowatt hours. Assuming a moderate 350 watt hours per mile, considering your car is a little on the heavy side and you're adding a lot of lead on top of that, in an ideal scenario and draining your batteries completely (to 0, which would be very bad for them), you would only get 13.7 miles. I dont know if you'd make it to 70, but if you did you wouldn't be there long.

Sent from my SM-N960U using Tapatalk


----------



## J_D (Feb 17, 2019)

Brilliant, thank you for your workings out, so in theory I would need more like 12x 50ah battery's to be safe.

Also in your opinion what, voltage DC motor would you choose? To try and get me to 60mph

Sent from my F8331 using Tapatalk


----------



## J_D (Feb 17, 2019)

*Re: An Intuitive Approach to Fissiks and Mechanics*



jbman said:


> This conversation is probably better had elsewhere, as it's not very strongly related to finding a good motor.
> 
> Sent from my SM-N960U using Tapatalk


Apologies, I was trying to work out my battery capacity to choose the correct voltage DC motor for my requirements. I hope this is Ok

Sent from my F8331 using Tapatalk


----------



## jbman (Oct 26, 2017)

*Re: An Intuitive Approach to Fissiks and Mechanics*



J_D said:


> Apologies, I was trying to work out my battery capacity to choose the correct voltage DC motor for my requirements. I hope this is Ok
> 
> Sent from my F8331 using Tapatalk


I meant the discussion over which units to use.

Sent from my SM-N960U using Tapatalk


----------



## eljay (Sep 26, 2019)

My first post here! 
I recently became fascinated with the thought of an EV conversion on an old car with a non-running ICE.

Let me follow J_D above and state my goals and facts and, hopefully, you can guide me to what motor should I look for as I don't know much about them, so don't want to make a stupid first decision. For example, I was looking at what looked like a candidate motor only to find that it is a treadmill motor. 🙂

My objective is to keep this a cheap project. Basically, cheaper or close to rebuilding an ICE. The vehicle would be a fun, occasional vehicle, no winter use planned.

The facts/objectives:
Car weight: ~900kg
Original horsepower: 60hp
Transmission: classic 5-speed manual with clutch. (Not needing a clutch would probably save the work on restoring that system in a vehicle that has been sitting a while.)
Range target: 40-50km (to get me anywhere in the city and back)
Top speed: 120-130 km/h (highway speed limit is 100-110 and sometimes you need to get the hell out of the way - although I know the acceleration at the high end won't be there)
0-100 km/h: 10 secs (more important would be the 0-60 km/h for those red light starts!)

So, I know I'm looking for a cheap forklift DC Series wound motor, but what is the volt and amp range I should aim for? Will any 24V-48V do? I realize it's the controller where the magic happens though. 
Is there a reasonably priced battery pack these days or to keep this cheap, should I stick to classic 12V auto batteries? I can probably stuff 8-10 of those easily.

Thank you very much!


----------



## Duncan (Dec 8, 2008)

Lead is dead - with lead actual ranges were less than 20 miles and 2 years for life
For your needs a Chevy Volt pack would be great - I paid $1800US for mine

Motors - most here are 48v 
But you will be running them higher 
I'm running 340 volt - but that is excessive - 150v is OK - much below and your top speed will suffer

This is my "Device"

https://www.diyelectriccar.com/foru...dubious-device-44370p15.html?highlight=duncan


----------



## eljay (Sep 26, 2019)

Thank you.
So, 48V motor is what I need?

It sounds like battery will be the "not cheap" part of my or any project.
How much of a battery pack do I need?


----------



## MattsAwesomeStuff (Aug 10, 2017)

> So, 48V motor is what I need?


Series-wound motors don't really have voltage limits. They just have the voltage that the truck was run at. I'm skeptical if there's even a difference between a motor from a 24v lift and a 48v lift. I dunno, maybe there is.

Either way you'll be running them at several multiples of their original voltage.

You need a motor the right size. With a light car like that you might pull off a 9" motor, but 11" is probably better. Generally anything that diameter will be the right ballpark size.



> It sounds like battery will be the "not cheap" part of my or any project.
> How much of a battery pack do I need?


You have quite modest battery requirements.

You only want 30 mile range. For your light car, perhaps 250 watt-hours/mile, so, 7500 watt-hours. That's incredibly small, you won't find anything that small in an OEM EV.

A Chevy Volt pack is quite small, and even it is 16,000 watt-hours. I'd go with one of those.


----------



## brian_ (Feb 7, 2017)

MattsAwesomeStuff said:


> You have quite modest battery requirements.
> 
> You only want 30 mile range. For your light car, perhaps 250 watt-hours/mile, so, 7500 watt-hours. That's incredibly small, you won't find anything that small in an OEM EV.


True, but you will find that in the lower-capacity plug-in hybrids. The Volt is a higher-capacity plug-in hybrid... like the Chrysler Pacifica Hybrid and Mitsubishi Outlander PHEV.

Perhaps more importantly, all modern EVs and hybrids use higher voltage than will likely be used with a brushed DC motor. If you use, for instance, one-third of a 360 V EV pack to get 120 V, you have one-third of the energy capacity... that's only 8 kWh for an early Leaf.


----------



## eljay (Sep 26, 2019)

Thank you.
I see a few hybrid battery packs from Prius and Camry available. So, those would be suitable? And I'm looking for around 8kWh?
Looks like Prius Gen 1 is only 1.6kWh and Gen 2 is 4.4Kwh.
And are controllers and BMS hard to find/match for those?

P.S. Please let me know if I should start a thread in the battery section instead of here.


----------



## brian_ (Feb 7, 2017)

eljay said:


> I see a few hybrid battery packs from Prius and Camry available. So, those would be suitable? And I'm looking for around 8kWh?
> Looks like Prius Gen 1 is only 1.6kWh and Gen 2 is 4.4Kwh.
> And are controllers and BMS hard to find/match for those?
> 
> P.S. Please let me know if I should start a thread in the battery section instead of here.


Yes, this is a battery question, not a motor question, unless you are determined to use the motor, controller, and battery all from the same donor.

And the answer to that battery question is that non-plug-in hybrid batteries are too small, but plug-in hybrid (Prius Prime, Chevrolet Volt, Chrysler Pacifica, Mitsubishi Outlander PHEV, etc) batteries are around the target energy capacity... as long as you want 360 volts.


----------



## Duncan (Dec 8, 2008)

eljay said:


> Thank you.
> I see a few hybrid battery packs from Prius and Camry available. So, those would be suitable? And I'm looking for around 8kWh?
> Looks like Prius Gen 1 is only 1.6kWh and Gen 2 is 4.4Kwh.
> And are controllers and BMS hard to find/match for those?
> ...


I would be looking at more than 8 kWh

I have 14 kWh in an 800 kg car - and that gives me a 50 km range at 100 kph 

Admittedly my car is aerodynamically challenged!


----------



## eljay (Sep 26, 2019)

Duncan said:


> I would be looking at more than 8 kWh
> 
> I have 14 kWh in an 800 kg car - and that gives me a 50 km range at 100 kph
> 
> Admirably my car is aerodynamically challenged!


Forgot to say thanks!
Sounds like this will be the expensive part.
I need to find a motor first though and research the other pieces.


----------



## Alex A (Apr 16, 2020)

Duncan said:


> I would be looking at more than 8 kWh
> 
> I have 14 kWh in an 800 kg car - and that gives me a 50 km range at 100 kph
> 
> Admittedly my car is aerodynamically challenged!


Hi. What car do you have? 800kg it's so light


----------



## Duncan (Dec 8, 2008)

Alex A said:


> Hi. What car do you have? 800kg it's so light


This is my "Device"

https://www.diyelectriccar.com/foru...dubious-device-44370p15.html?highlight=duncan

And 800 kg represents at least 150 kg more than it should have been - I overbuilt it a bit


----------



## viperking (Dec 4, 2019)

Hello Friends, 

I am just testing this induction motor with its controler. Maybe somebody detect this. So far it works ok, but somehow I dont like that fact that it must have electronic brake pedal. I am looking for somebody having this kit and was able to connect to ECU via its J1949 ,,and fine tune its drastic regenerative breaking.., It is bit technical question but maybe somebody else will be interested for this. It is 48-60V system 12 000Rpm / 1000A peak. Thank you


----------



## eSharo (Nov 20, 2021)

major said:


> Hi suk,
> 
> Not bad  Here's a couple of comments. Refer back to your #1 post for quote context.
> 
> ...


Hi Major,
One thing that I have a hard time to understand. Many folks on this site are suggesting to use a forklift DC motor to replace the original combustion engine. But as you say, an electrical motor HP and a combustion engine HP is the same... So, if I want for instance replace a 100 HP combustion engine and look at the 100 HP electrical motors outthere, they are a lot bigger than the typical forklift DC motors. And for some reason, these forklift motors are not showing the amount of HP they are providing on any nameplates that I looked at. So, how can you size a "good" forklift DC motor to fit your expected output power?

Thanks,
eSharo


----------



## Duncan (Dec 8, 2008)

eSharo said:


> Hi Major,
> One thing that I have a hard time to understand. Many folks on this site are suggesting to use a forklift DC motor to replace the original combustion engine. But as you say, an electrical motor HP and a combustion engine HP is the same... So, if I want for instance replace a 100 HP combustion engine and look at the 100 HP electrical motors outthere, they are a lot bigger than the typical forklift DC motors. And for some reason, these forklift motors are not showing the amount of HP they are providing on any nameplates that I looked at. So, how can you size a "good" forklift DC motor to fit your expected output power?
> 
> Thanks,
> eSharo


The motor is a device to convert electrical power into mechanical power
The more power you "feed" it the more mechanical power is produced

So the power that can be produced is determined by the controller - not the motor

A motor can produce a LOT of power if its only for a short period

Additionally 

Power = Torque x Speed

Torque is (roughly) proportional to Current - as is HEAT

So if you are going at twice the rpm THEN you can produce double the power for the same amount of heat
AND if the motor is cooled by a fan on the motor shaft - THEN you can cool and remove more heat

The result is that a Fork lift motor with a 10 kW "rating" at 1400 rpm will have about the same heat buildup at 
4,000 rpm and 50 kW
That would be the "1 hour rating"
Most cars will "do the speed limit" at about half of that (25 kW) - so they can't pull 50 kW continuously anyway

Short term power - for acceleration - can be much higher! 

I am feeding my 10 kW Hitachi motor with 400 kW for a short period


----------



## remy_martian (Feb 4, 2019)

The peak HP may be the same, but the torque curve vs RPM is totally different between a motor and an engine.

In both, the force at the tires at a given wheel speed is what matters. It has to at least balance rolling resistance, drag, and powertrain losses.

There's no magic - the wheel HP curves for an ICE and an electric motor vehicle have to cross over at a given speed on the graph, or the electric has to at least equal or exceed the ICE WHEEL torque at that given speed.

In a motor, you can alter that output for short periods, as Duncan has said. When you need it...at low speed for short periods of time. In an ICE you have to slip the clutch to multiply torque....for short periods of time, also.


----------



## eSharo (Nov 20, 2021)

Thanks a lot guys. 

Waiting for your replies, I educated myself in parallel and found out many interesting things on the subject on this forum and on the net. 

What I understand better now is that the required starting torque for a DC motor is not an issue since the lower the RPM, the higher the torque for a DC electrical motor.

My main concern now is the higher speed torque peaks required for say hill climbing or higher speed acceleration. For a given voltage supply, the generated HP will be the same so that for higher RPM, I will get a lower available torque. But on the other hand, I can configure the controller to supply higher voltage to generate higher HPs (raise the "speed-torque curve") therefore, higher torque for a given RPM. But in this situation, the dissipated heat may be a problem but as Ducan said, a fan installed on the motor shaft would help a lot.

I figure out that I will not be able to anticipate completely the behavior of a given DC motor to replace my current engine while designing my system but as a general rule, I will choose the highest possible HP rated motor available with the ability to install a fan on its shaft if not already equipped as such. I will also plan for a controller that will allow to supply higher voltages (higher than the nominal voltage of the motor) at higher RPMs. Since I will keep the current transmission in the vehicle, my sweet spot RPM for a 100 KMH speed will be around 2000 RPM as it is now. So, I'll have to keep a fairly good acceleration (torque) beyond this RPM until say about 2500 RPM. The rest of the story will be a try and "error" workbench test plan making sure that I will not let the motor to overheat not to damage it.

Any other comment from the community would be welcome!

Thanks!
eSharo.


----------



## Duncan (Dec 8, 2008)

eSharo said:


> Thanks a lot guys.
> 
> Waiting for your replies, I educated myself in parallel and found out many interesting things on the subject on this forum and on the net.
> 
> ...


Kind of!!
But its better if you think about Current = Torque
Your controller will alter the Voltage it feeds to the motor in order to deliver the demanded current - up until 100% when the Motor voltage = Battery voltage 

Rather than
the lower the RPM, the higher the torque for a DC electrical motor
In most cases you have the same torque up until you don't have enough voltage to sustain that current THEN as rpms rise the current and the torque both drop

Most motors will survive a lot more than 2500 rpm - and its better to operate at higher rpms - also gearing for 100 kph and 2000rpm is difficult!!!


----------



## eSharo (Nov 20, 2021)

Thanks again Duncan. I got you... But regarding the 100 KMH at 2000 RPM, there is nothing I can do since it is the current built in mechanism characteristics. But I will try to find a controller to have the ability to cope with it and, as I said before, provide a battery pack that will supply higher voltage than the nominal voltage of the motor. This will leave the controller to adjust the voltage to cope with the torque (current) demand at higher RPMs. Sounds good?


----------



## Duncan (Dec 8, 2008)

eSharo said:


> Thanks again Duncan. I got you... But regarding the 100 KMH at 2000 RPM, there is nothing I can do since it is the current built in mechanism characteristics. But I will try to find a controller to have the ability to cope with it and, as I said before, provide a battery pack that will supply higher voltage than the nominal voltage of the motor. This will leave the controller to adjust the voltage to cope with the torque (current) demand at higher RPMs. Sounds good?


If you are keeping the transmission simply use a lower gear
Top gear may be 2000 rpm for 100 kph - but lower gears will be more revs - first gear is usually three or four to one 
So in first it will be 6,000 to 8,000 rpm at 100 kph

Keeping the revs up will reduce the heat as the motor will be spinning faster and you will require less current

You may well find that you never use "top gear"


----------



## eSharo (Nov 20, 2021)

Makes very good sense to me... Thanks a lot!


----------



## eSharo (Nov 20, 2021)

eSharo said:


> Makes very good sense to me... Thanks a lot!


But thinking at loud, if the lower gear RPM is too high, I may end up with a mechanical problem. But I am sure you have a point, I will have to fine tune the selected gear with the proper RPM to take down the supplied current while cranking up the RPM. But my point is that it will not be a tuning based on "the the highest RPM is the best" scenario because of mechanical restrictions. I will figure out all of this on my workbench.


----------



## rtchow (Nov 24, 2021)

sukusia said:


> So here is what I learned about motors from this site. I wanted to post a quick reference so newbs (like myself) do not have to sort through the sticky page.
> 
> *When looking for a forklift motor:*
> Get a series wound motor because they have very high torque and handle abuse (over volting) a lot better.
> ...



thanks, that was a mouth full. i thinking seriously converting my 1971 MG BGT 1800cc. it's got great power and tuned per MG spec. I could sell the original motor and keep the tranny for the conversion. do you know where to get the adapter plate to mate the E-motor to the MGB tranny or make an aluminum for light weignt? what is the best and high effeciency lithium ion phosphate battery, the cost, number of cell per pack? i'm just tire of paying high gas price. what would be an ideal budget for this venture?


----------



## Duncan (Dec 8, 2008)

rtchow said:


> thanks, that was a mouth full. i thinking seriously converting my 1971 MG BGT 1800cc. it's got great power and tuned per MG spec. I could sell the original motor and keep the tranny for the conversion. do you know where to get the adapter plate to mate the E-motor to the MGB tranny or make an aluminum for light weignt? what is the best and high effeciency lithium ion phosphate battery, the cost, number of cell per pack? i'm just tire of paying high gas price. what would be an ideal budget for this venture?


First and most important with any conversion - what range do you need?

Range - and hence battery size required sets the rest of the needs


----------



## remy_martian (Feb 4, 2019)

What mechanical restrictions?


----------



## jgerig42 (1 mo ago)

MattsAwesomeStuff said:


> Dunno if you wanna say where you are, but... the thing about forklifts is literally everywhere in the industrial world has to have a place that services them in just about every city over 50,000. Everyone needs forklifts, everyone needs a place to fix them.
> 
> I have a sweetheart deal with mine. They'll move a forklift up on jackstands for me, outside the gate, and I can come help myself to it at night over a week or two, gutting what I want off it. And they don't charge me for anything I take. And I can occasionally borrow tools when there's something I don't have big enough tools to tear up. And they leave me deserts sometimes. The tradeoff is I show them pictures of what I'm working on.


Dude, Where are you located and if you're not too far will you sell me a motor?!
I'm in the Los Angeles, CA area and am having trouble locating one. When I call repair shops or forklift scrappers they all seem confused and say something like "No, we _repair_ motors, we don't _sell_ motors" like I'm crazy for asking.

I mean... mechanics repair engines but most of them still have one or two lying around that they'd sell if you asked


----------



## remy_martian (Feb 4, 2019)

LA has a Sanford and Son ecosystem of scavengers, so a repair shop is probably a bad place to look.

Damien, Matt, and Duncan let out a can of worms, a Heisenberg Uncertainty Principle perversion, by stating publicly "you can get a forklift motor for free", so if there were any, they'd be rare as hens teeth these days, imo.

With copper prices through the roof, and iron not exactly cheap either, it'll be a rare pack rat that has one that didn't go to the scrapman, especially since modern day forklifts usually use non-brushed motors, so there's no point keeping it around.

That means you need to buy a Hyper9, FB-4001, or similar and drop the fantasy of doing an EV conversion for $1000. You can still keep looking, you might be the exception, but anything in stock is no longer cheap.


----------



## floydr (Jun 21, 2021)

Maybe try Bakersfield, Go to the shops with money in hand if you have been getting no where with calling. Which it sounds like. Ask the forklift repairmen if they know of anyone that has an old DC forklift motor. I understand The asking in person money in hand works sometimes.


jgerig42 said:


> When I call repair shops or forklift scrappers they all seem confused and say something like "No, we _repair_ motors, we don't _sell_ motors" like I'm crazy for asking.


Write down what you are trying to do, maybe people will understand. 
keep an eye out for deals craigslist, bulletin board, friends, family, co workers etc
later floyd


----------



## jgerig42 (1 mo ago)

floydr said:


> Maybe try Bakersfield, Go to the shops with money in hand if you have been getting no where with calling. Which it sounds like. Ask the forklift repairmen if they know of anyone that has an old DC forklift motor. I understand The asking in person money in hand works sometimes.
> 
> Write down what you are trying to do, maybe people will understand.
> keep an eye out for deals craigslist, bulletin board, friends, family, co workers etc
> later floyd


All good advice, thanks!


----------



## MattsAwesomeStuff (Aug 10, 2017)

jgerig42 said:


> Dude, Where are you located and if you're not too far will you sell me a motor?!


Canada.

So, no.



> I'm in the Los Angeles, CA area and am having trouble locating one. When I call repair shops or forklift scrappers they all seem confused and say something like "No, we _repair_ motors, we don't _sell_ motors" like I'm crazy for asking.


Yeah, motor rewinding places aren't somewhere I'd suggest. They don't have motors in inventory that I've ever seen (though I haven't seen many).

...



floydr said:


> Maybe try Bakersfield


So, problem with Bakersfield, and Southern California in general, with free, is Mexicans.

Where I'm from, everyone is generally well-off, well-educated, and there's not a lot of poverty. So there's not a large culture of squeezing every drop of value out of something. There's a high amount of waste.

For example, around here you can fully furnish an apartment, every day, for free, with good stuff, just from Freecycle or free facebook or our Craigslist equivalent. People here throw away appliances not because they're broken, but because they're the wrong color. Perfectly working, expensive items have negative value because people just want them gone. Ditto for couches, kitchen tables, etc. Back in the day, most of my friends bought a new computer every year. If you were okay with a 1-year old computer, they were just going straight to a landfill.

That doesn't exist in places with poverty, or a lot of illegal immigrants that can't participate in the formal economy, or where a large portion of the population grew up with very little. People don't just leave money on the table like that. If there's $20 to be made, someone's out there making that $20.

When I lived in SoCal (and Bakersfield), there was basically nothing anywhere for free. For a scrounger, that upset me.

The flip side of this, is that there is a heavy underground scrapper market for everything down there. Up here you'd have no choice of buying something really cheap, because it's not worth anyone's time to administer selling it. You can even ask and offer to take it away for free, and most people don't even want the hassle. We have giant scrap metal dumpsters here, that people PAY to have someone haul away for them, as if free metal is a waste product (because, it is). But down there (and, in worse parts of town up here I'm sure), if you just ask around, you'll get hookups for everything. If you put out to the right people that you want a forklift motor, and you'll pay $50 over scrap value for it... the hunt is on. They'll find you one. Zero chance of that ever happening up here. You'll have to be where scrappers go though. Places that might throw away scrap metal perhaps, or scrapyards itself, if they have a posting board.

You have almost no chance of getting one for free, but you have a great chance of there actually being a market for "slightly above scrap value components".

Also, one thing perhaps I, and perhaps others neglect to consider... is that some of us are just socially charismatic and persuasive, in unconventional ways. This isn't a cocktail mingle event, but lots of people on the bluer collar of town have their equivalent of it, and, knowing how to read people, inspire them to go a little out of their way and a little ways around what their lawyer might say, to find common ground about what parts of your project they find sympathy with and excitement in, is a huge part of getting this done. I talked my way into every single recycled tool battery in my half of the province being put in a bin with my name and number on it. It's probably not reasonable to suggest that because I was persuasive, that anyone else could be in a similar way.

A common thing people say is to just show up with a case of beer and talk to the guys in the back. They'll eliminate what you want from the waste stream without the front office having to approve liability and why the sales team isn't involved. I don't really even know how to do that, or to start that conversation. Do I bring the beer with me? Do I leave it in the car? Do I drop it off later? Won't you just get run off the property if you show up at the back where the maintennance guys are? And yet that's probably the most common piece of advice for blue collar currency for uncommon requests. The guys who can work that into conversation are a whole other tier above me. I have a feeling this power arrives when your beard turns grey.


----------



## puddleglum (Oct 22, 2008)

I haven't posted on here in a long time, but you caught my attention so I think I'll chime in. I agree with what matt said, but in addition to it, I'll throw out a couple of thoughts to consider. I repair forklifts for a living, have for almost 18 years. We've never once sold a used motor. I have however acquired 4 complete forklifts over the years for cheap or free, and could have had more if I'd wanted to. It's all about being in the right place at the right time. You would probably have more success finding a complete dead forklift, stripping out what you want and selling the rest for scrap. You won't get answers at the front counter. Your best to find a field tech, or even a sales guy. What you ask is if they know of someone who has a junk forklift that that's too expensive to fix. BUT,1) it probably still won't be free and it may require more work than you want to put in. You'll likely have additional costs attached for transport as well, plus there are not really that many good candidates for suitable motors left around IMO. 
2) the other thing you need to consider is that cheap DC controllers have become even more rare than motors and you may not have a way to use one, even if you can find one. I've got 2 good motors sitting in my garage that I wanted to use for a conversion for a long time, but now the options for controllers are gone, unless you are an electronics tech and can build you own. We're a little late to the party I'm afraid. The majority have moved on to AC, which is better tech for sure. and with lots of EV's in wrecking yards now, might not be any more expensive. 
I still have a soft spot for DC, but mostly because I hate to throw anything away that I already have.


----------



## remy_martian (Feb 4, 2019)

And good luck getting parts if you decide to build one.

I found a few microcontrollers on promise of delivery in a couple of months, spent the money on an order, and a day later they pushed the delivery to the end of the year. This evg I sent a cancelation notice and requested a full refund, cuz Homey don't play dat.

Even simple things like voltage regulator chips are Unobtanium, so if you decide to build something, fat chance you'll find the parts for it. If you can make a decent lunch with whatever is in the refrigerator, like I tried to do with the micros, you still get screwed.

They laid off all the good people a few years ago and this components mess is partly because the lunatics and bean counters have been running the insane asylum ever since. And the Chinese appear to be hoarding every part they can get their mitts on.

Make sure you have all the pieces of the puzzle...


----------



## piotrsko (Dec 9, 2007)

Bakersfield is a petroleum/ oil service economy that has warehouses. The seedier parts of town like oildale, buttonwillow, Arvin, or Lamont may still have scrapyards but like Remy said, stuff has too much value to just take to the dump for free. At 200+ lbs, a 13"motor has scrap value of beer and the gas to get there. There's a forklift recycle place in Stead, but they don't do electric. We have a motor rebuilder here in Reno, but their scrap pile is full price and they want $$$$ to rebuild, $$$$$$$ to rewind and 6months to get around to it if they like you. That's only good if you have an antique thing that generates you a pot load of Ben Franklins to pay for the repair.


----------

