# Rating Forklift (and other) Motors



## GeeDub (Jun 25, 2008)

Just read through the entire 'Using a forklift motor, and choosing a good one' thread.
I saw a lot of : Will "X" motor power "Y" Vehicle? questions.
After about page 15 it became information overload for someone new like me. Too many cross references and tangents to keep track of.

Any chance you more experienced guys can develop a Class Rating for the uses of these motors?

Like, Class A = electric weed whacker, Class J = Harley Cruiser, Class P = Lincoln Town Car, Class T=Escalade, Etc.
Maybe start at D like in Diamond Grading, in case you have to add classes later.


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## major (Apr 4, 2008)

GeeDub said:


> Just read through the entire 'Using a forklift motor, and choosing a good one' thread.
> I saw a lot of : Will "X" motor power "Y" Vehicle? questions.
> After about page 15 it became information overload for someone new like me. Too many cross references and tangents to keep track of.
> 
> ...


Hi GeeDub,

Offhand I'd say too many variables. I wouldn't attempt it. In the industry, you have application engineers who analyze the whole deal for each. You just have to rely on the motor ratings and your vehicle calculations. Also, go with what's worked for others.

I know, not much help. Maybe somebody else has the time to do it.

Regards,

major


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## Hi Torque Electric (Dec 23, 2007)

Hey Gee

There are motor out there that have a lot of track history which have some data on them to go by. When dealing with lift motors it becomes a different story as there are just hundreds (if not thousands of motor types available for use) Trying to create a list (with cross refferences) is/ would be beyond my available time (and energy) restraints.

In as much as you've stated the lack of available info, I see nothing here stating your needs? which make it impossible for anyone to offer info as to what you'd need.

In general a 36/48 volt lift motor, in a 100 to 150 lbs weight class would do most conversions well.
Hope this helps
Jim Husted
Hi-Torque Electric


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## GeeDub (Jun 25, 2008)

Hi Torque Electric said:


> In as much as you've stated the lack of available info, I see nothing here stating your needs? which make it impossible for anyone to offer info as to what you'd need.


Actually Jim, I wasn't referring to *my* specific needs. I haven't figured out what I'm going to do yet. In fact, I will be working backwards; I am planning to find a 2 or 3 used motors, and then decide what to put them in.
It just seemed that if someone says I want to do a 4000lb truck, you could suggest "any motor in the P through S class". If they say they want to make an electric bicycle you could suggest "any motor in the D and E class". There must be some common denominator in all motors that can be used to subdivide the many.
In reading all these posts, I'm starting to see almost the same questions about motor suitability asked in different ways. They are usually variations of "What should I use in "X" car, bike, pickup, whatever.

...Now that I think about it, another way would be to rate the application vehicles by weight classes. For example: Class G = vehicles ranging from X lbs to Y lbs. Anyone having a vehicle in that range could add that car to the universal list.


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## JRP3 (Mar 7, 2008)

The best thing is to look for real world examples of either the motor you want to use or the vehicle you want to use. Go to www.evalbum.com and use the search function to select motor type or vehicle type and see what is used and how it performs. In my short time researching I've come to see that motor diameter and weight are a good way to judge performance for a series DC motor.
My 7.5 inch 60lb. Yale from Jim moves my 750lb 6x6 quite nicely at 48 volts and it would really move it at 72, or 120! It would probably be great for a motorcycle and maybe even be ok for a very lightweight small car with low performance expectations but you'd be better off with an 8 inch, or 9 for more performance.
Medium sized vehicle a 9 inch would do well, for a large vehicle or high performance medium vehicle go with an 11 inch.


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## Hi Torque Electric (Dec 23, 2007)

Hey Gee, all

When talking about motors that are designed to be used in car then what you're desribing has been done (I believe KTA services was the first or at least one of)(EVen this is far from idiot proof 8^) When talking about using lift motors it becomes a bit more difficult to narrow down. In as much as a motor's a motor, there are lot's of flavors out there (like hundreds) and as I've posted before just because motors look the same on the outside, doesn't mean they are even close to the same on the inside.

Let's forget that there are sep-ex, or compound wound motors and just look at series wound lift motors. Some are designed well, are user friendly and work and run well, while some, are built poorly and very user un-friendly (to the point I'd like 5 minutes in a dark room with the sadistic bastard who designed them 8^o Even with 27 years of building lift motors (just a few for EV's)(so I'm still learning) am amazed or dismayed by how well or poorly a particular motor works in the field. Damon Henry's little 70 lbs motor I helped his son Mike build (just got my first ride in it last weekend) just blows me away with how well it's doing in in a Datsun truck.

Another thing when generlizing stuff (such as a cars weight) you're assuming that they all run the same gear ratio's, or that each driver has the same driving conditions (let's say hilly travel vs flat travel). In general the addage "what's good for the goose isn't so good for the gander" applies fairly well here. Another factor is one guy doesn't mind driving a NEV like performing car, while another would be crawling out of his skin for lack of acceleration. So there really are a number of factors to concider.

That said, and in as much as it's a good idea in theory, it's a daunting task to compile, and beyond my means in time to spend on it (I've still got a motor basics FAQ sheet unfinished I've had on my plate the last year to finish 8^( So any out there who'd like to compile a list of stuff we know works with X car, and wants to write it up, by all means knock yourself out

IMO, it's better to look at these individualy in hopes they create a good match between driver, car, and motor.

In general, pump motors are better suited to use than the lift drive motors, but they lack the needed shafts (sometimes the needed rotation) and make them hit or miss) Drive motors tend to be somewhat heavier than needed (it's better to carry that weight in batteries). In general 100 to 150 lbs of motor is well suited for "most" conversions. In general these motors should be advanced by 10 degrees to make them better suited to the voltages being used. In general...

Well, that's about all the time I have this morning, hope this helps.

Jim Husted
Hi-Torque Electric


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## Telco (Jun 28, 2008)

This is the same question I've been asking on many forums, with no answer, but in my case was hoping to see something like "an electric motor of X voltage and Y amperage would act like an ICE with X HP and Y torque". I realize there are thousands of combos of each, but there should still be some way, or some rule of thumb, to sort the electric motors and have an idea of what kind of pull they can make in relation to an ICE. The closest I've seen to this is "you need 1HP on the EM for every 3HP your existing ICE is" but that still makes for a pretty big EM.


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## JRP3 (Mar 7, 2008)

Part of the problem is that what a motor puts out is dependent on what you put into it. So a motor run at 48 volts 400 amps gives you one figure and the same motor run at 72 volts 400 amps gives you another. So if someone asks what the hp of that motor is the answer is it depends on the voltage and amperage you run it at.


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## ngrimm (Oct 19, 2007)

I agree with all that's been said above but will add that imho it's not that much different than gasoline engines. I've got a 700 cc twin cylinder Briggs engine in my horseless carriage that runs 18 hp. A 700 cc motorcycle engine easily has 60+ hp and is probably lighter too. There seems to be no substitute for experience.


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## Hi Torque Electric (Dec 23, 2007)

Hey all

Here's my take on the ICE to EM (electric motor) tit for tat. Volts times amps is watts, and I use the 1000 watt per HP rule as it accounts for heat and friction losses as nothing's 100% eff (and it makes the math easy 8^)

100 volts at 10 amps is the same power as 10 volts at 100 amps, which is a 1000 watts and 1 HP. That said, throw 100 volts and 400 amps into a motor and you'll produce 40,000 watts and will net you about 40 HP. What we need to look at now is how long is a particular motors duty cycle at that power level. A motor running 80% eff will heat up faster than a motor running 85%. Bigger motors tend to be more eff than using a smaller motor, but yet that applies (IMO) more to stationary motors as when using a bigger motor you're carrying around more weight (and weight probably better needed in batteries) (EVeryone is battery limited right now)(EVen the exotic battery using guys 8^) (who doesn't want more range?)

By blower cooling a motor you can increase it's duty cycle (no real data by how much) but it can be by nice amounts. By using two smaller (but like types) you can split the load each sees and you've double (generally) the brush to commutator size when compared to the same "mass" sized single motor. Furthermore, larger motors have a larger diameter and more rotational mass to spin up and I'm noticing they appear more like lumbering giants compared to a smaller motors fighter jet type launch. Being EM’s have full torque at 0 RPM, they tend to take off better than an ICE (Watch some White Zombie video’s on you tube)(you have to type in electric car after it’s name or you just get rock videos, lol) and you’ll see it launches faster than it’s equal HP counterpart, but falls flat at the top end, which is where the ICE regain ground so there is a shift to where the power band is per se.

I just talked with John Wayland this weekend and had asked what HP he thought the Siamese8 was making and he said about 250 he thought (it’s never been Dyno’d)(Killacycle bent the tiedown frame and broke a tie strap and said he’d never try again as it was the scariest thing he’d done todate. So if John threw 2000 amps at 160 volts (I’m using just basic what if figures here, but should be close 8^) he’d be putting in about 320 HP and producing 75% of that to the wheels). If in fact he’s doing 250 HP and smoking 400 HP cars (although you really have to compare apples to apples (example race twin cars) to see that HP to HP stood) but would indicate that you can do more with less compared to an ICE (if you got the right set up). Do it poorly and you’ll burn your motor up like a marshmallow dropped on a campfire. 

Truth be told I don’t know (for that matter even understand) everything as there is a learning curve. This is why I tell people all the time (specially when their goals are lofty) to start smaller, as there will be stumbling blocks along the way. That, and the simple fact that rarely is someone a master of anything the first time they do it 8^) The education learned is well worth the piece of crap you create, LMAO but now it’s a small piece of crap and the wife isn’t pissed to bad, and your big project goes smoother and much better (and you get to sleep in the house again)(although you got to build a third one now, cause the wife took over the second one)(and the kids use the first 8^)

That said, I applaud your want, to become an educated consumer, but you’re going to find that in many areas it’s uncharted water out there. I’m sure Columbus was asking the same questions… But how far off the map does the water go, 8^) Someone’s got to sail it to answer the question. There is in fact a lot of data out there from people who have sailed before you though, and with some homework, you can see what others have done, and used at the EV photo album for enough info for you to plot a course without having to re-invent the sail 8^)

I hope this sheds some light on the mysteries that might be holding you back. For me, a good motor is like art, I can’t spell it, but I know when I see it 8^o
Until next time
Jim Husted
Hi-Torque Electric


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## Telco (Jun 28, 2008)

That actually does help quite a bit, feel like I just stepped from the kiddie pool to the shallow end of the big kid's pool. Be a while before I'm swimming in the ocean. Will have to investigate this twin motor scheme you're talking about, I like the sound of that.


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