# Reverse Trike



## Jesse67 (May 12, 2009)

Interesting idea, how you set it up really depends on what you are looking for in the end. Are you going to be pedling as well? What sort of top speed and range are you looking for? Will the motors run through the standard bike derailer enabling shifting or will it be single speed? 

For an electric recumbent trike I don't think you'll need 5 of those motors. The thing to do would be to find if that 8.2 amps @27 V is a continuous current rating or peak short term current rating. If it is a continuous rating the motors should be able to take much more current (~20 amps? ) for a short period of time and thus produce a lot more torque for accelerating or hills etc. This should get you moving pretty quickly. 

Going without a controller well mean the motors are either on or off so you will pull a lot of amps right from the start, You could potentially have a lot of fun or burn something up! Probably a motor. But you have 5 so hey hook something up and give it a try. Thats the best way to learn. Have a look at electric bike conversion kits, there's lot of places that spec controllers, motors, throttles batteries etc. Even just looking at the specs for those should give you a good idea how to set yours up.

Cheers!

Jesse


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## ithinkidontknow (May 14, 2009)

Jesse67 said:


> Interesting idea, how you set it up really depends on what you are looking for in the end. Are you going to be pedling as well? What sort of top speed and range are you looking for? Will the motors run through the standard bike derailer enabling shifting or will it be single speed?
> 
> For an electric recumbent trike I don't think you'll need 5 of those motors. The thing to do would be to find if that 8.2 amps @27 V is a continuous current rating or peak short term current rating. If it is a continuous rating the motors should be able to take much more current (~20 amps? ) for a short period of time and thus produce a lot more torque for accelerating or hills etc. This should get you moving pretty quickly.
> 
> ...


I am sort of sure that these values are the continuous rates; I have attached the spec sheet for the motors if that helps. I will not be pedaling this bike at all, the picture I posted was just a reference for the shape and general design of the bike. I plan on driving the motors directly to a single pedal gear and make use of the front gears for shifting. I don't know if this is necessary if I can get fairly good control out of the controller alone. 
My goal for this is to be able to go up to about 40mph with the bike (including me) weighing about 400 pounds. I would like to get as much range as possible and would like to try to engineer it to maximize my range. Even if I don't use all 5 motors, I would definitely want to use more than one (maybe 3 or 4) and I could keep the extras as replacements. 
But back to one of my original questions, can I run these motors in series or do they have to be run in parallel? And, what will the affects of doing each be?
I also am trying to buy some batteries this weekend, and after doing a short search, it looks like my best bet is to buy the batteries from Sears. Does anyone have any experience with these "DieHard" batteries? I might look to get some marine batteries rather than car batteries as they seem to have higher cold-cranking amps and amp hour ratings at around the same price. Any insight on this would be appreciated.
Thanks


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## Jesse67 (May 12, 2009)

What is the original application for the motors? They appear to have 3 torque/ speed settings so I'm guessing a heavy duty fan motor. If so they may not work very well for an electric vehicle.... A heavy duty electric bike hub motor would greatly simplify things, ie no gearing to worry about so your range would be much better. But that would make it too easy and take all the fun out of it! 

Motor speed is proportional to voltage and motor torque is proportional to current. So if you wire the motors in series each motor will get the full current but the voltage will be divided across each so less speed, more torque. If you wire them in parallel each motor will get the full voltage but the total available current will be divided between them. Less torque more speed. 

From my understanding I don't think the controller cares about series or parallel as long as it can handle the total current being drawn. Usually higher voltage systems are more efficient (ie longer range) because they need less current to give the same power, less current means less losses in the wiring, batteries and motor windings. 

A couple more things, it looks like you're showing a gearbox with a 60 : 1 ratio plus the gearing that gangs the motors together, this will give you a slow walking speed. With a 4000 rpm motor and standard diameter bike tires you'll need ~10:1 gearing to get to 40 mph. If you can simplify your gearing you'll make it a lot easier on yourself trying to get this built! 

For batteries make sure you get deep cycle batteries not automotive starting batteries. Don't worry about cranking amps, if you want range you want amp hours. 

Have fun!


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## ithinkidontknow (May 14, 2009)

Yep, you're right, these were made for aircraft ventilation shafts. I definitely have money in mind and I also just want to have some fun so if these motors end up not working I might give some other motor a try but seeing as I got these for 5 bucks a piece, I might as well try to put them into some good use. 

So if I understand what you said right, If I had lets say 4 12v car batteries in series and 4 12v motors in series, it would be able to function? Would this still only draw 8.2 amps? Also, a bonus in torque might be quite nice but it seems like there could be a potential downside to this (burning out the motor possibly).

The 60:1 was a mistake I made in my math when I was just messing around in the beginning. More recently I figured out that for my gearing calculation I estimated my motors could probably only spin at around 3700 rpm under a load and I thought that I would probably only need about ~6 rotations per second to go the speed I want. So, to gear from 3700rpm to 360rpm I need a reduction of around 10:1, you are exactly right.

Do you have any idea where I can find deep cycle batteries or what sort of stores sell them? I have seen tons online but I need some sort of idea of the price before I can really get involved. What sort of amp-hr rating does the usual lead-acid battery have? I have seen ones around 20 but I think it would be cool to have much more, especially if it is within a reasonable price. 

Thanks for all the help


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## Amberwolf (May 29, 2009)

A few points:

First, I would recommend you keep intact the original bicycle rear drivetrain (see my Crazybike2 in my blog as an example), and that you also leave pedals on the bike. 

Leaving the original bike drivetrain will let you have different gear ratios available for shifting so you can handle hills vs flats better, and also for full stop into motion situations, which will be common in traffic. 

Having pedals gives you two things: 
--a way to get home if the motor system fails 
--a way to help the motors move you if they don't have enough oomph to get started on a hill or with a heavy load, etc., especially if the batteries are low.

A third benefit of pedals is that if your state/etc requires them as part of the definition of a bicycle, you won't have worry so much about being ticketed due to not having whatever else is required of motor-driven-cycles, mopeds, or motorcycles, whichever one they choose to classify you as at the moment the tickets are written. 


If your pedals *and* your motor both go to the same regular drivetrain, then if you do like my CrazyBike2 does and setup the motor for around 90-100RPM, and your pedal chain input to the same drivetrain for the same RPM, then the bike drivetrain will operate pretty much just like it would have for any bike, and give you the same range of speeds for both pedals and motors. 

If you have a freewheel at both motor and pedal inputs to the system, then neither one has to drive the other, so are both independent and won't interfere with each other. I have a very simple device I'm working on prototyping that will make this really really easy to do, but I'm still waiting on access to a mill/lathe with thread-cutting gears to be able to make it. Until then, I don't have the freewheels on the CrazyBike2, either, so both systems drive each other, which is very undesirable. 


You probably don't need all five of those motors. That'd be in theory about 1100W. You probably only need half of that, so three motors would be sufficient. Using all five will give you more overhead room, but will also weigh more and take more power all the time, unless you have a way to physically switch them in and out. 

In addition, that might be more power than you can legally put on a bicycle in your area, without reclassifying the vehicle as a moped or motor-driven-cycle or something, along with whatever requirements that kind of vehicle has in your area. 1HP seems to be a common guideline whenever I've seen one given, but some places are much less.

The new motor you have, 2.5HP, is even more powerful than these are in total, at roughly 1875W. You probably won't need even a third of it's power, depending on what you want out of it.


For batteries, U1 deep cycle batteries like those on some powerchairs are good enough if you really want to use lead-acid, but they still weigh about 23 pounds each. I use two (will have three on the trike) and it's HEAVY. 

I don't know costs, but when new they had a capacity of 12V31Ah. I'd guess I have some large fraction of that left by the time I got them. 

Buying online is not recommended for SLAs, because they'll cost you an insane amount for shipping, most likely. If you have a Batteries Plus near you, they carry a bunch of SLAs and can order others. Stores and shops that service wheelchairs and powerchairs also carry them. 

As a side note, 12V12Ah batteries weigh around 9 pounds each. The 31Ah's I have are around 23 pounds each. I think the 20Ah were around 17 pounds each. Remember that to draw more current without damaging your batteries you need to have bigger ones, but you probably shouldn't get batteries that are bigger just for the sake of being bigger, unless you need that extra power capacity. Otherwise you will be carrying around a lot more weight, and it will cost you a lot more. 



The other replies you've gotten already point out a lot of good info, too. 


As for the bike itself, one bit of info is that the longer the bike is, the wider it needs to be to counter the force of a turn without tipping over. Having the heavy batteries and motor on there will help to counter that. I'd recommend putting the batteries as far to the front as you can manage. On my trike, they'll be directly over the front axle line, or immediately behind it. The motor will be under the seat. 


FWIW, using just a simple powerchair motor that's probably only 300W, plus pedalling, lets me move my 120pound CrazyBike2 and my 150 pound self plus another 10-15 pounds of cargo at least 15 miles, using two U1 batteries, with the drivetrain method described above. 


Now, when reading my advice, keep in mind that the only thing I'm an expert on is how to turn various bits of junk into useful things they were never designed to be. 
________
Recall nexium


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## ithinkidontknow (May 14, 2009)

Amberwolf said:


> A few points:
> 
> First, I would recommend you keep intact the original bicycle rear drivetrain (see my Crazybike2 in my blog as an example), and that you also leave pedals on the bike.
> 
> ...


I planned on taking the pedals off originally because it significantly simplifies the drivetrain. I am thinking down the road I will design a system to pedal an alternator to recharge the batteries. Ideally, I would be able to register this bike as something other than a bike. Also, keeping the pedals off allows me to keep from running into problems with having freewheeling gears like you . 



Amberwolf said:


> You probably don't need all five of those motors. That'd be in theory about 1100W. You probably only need half of that, so three motors would be sufficient. Using all five will give you more overhead room, but will also weigh more and take more power all the time, unless you have a way to physically switch them in and out.
> 
> The new motor you have, 2.5HP, is even more powerful than these are in total, at roughly 1875W. You probably won't need even a third of it's power, depending on what you want out of it.


The other 5 motors that I have probably wont work for my project like I originally thought as they are extremely low torque fan motors. The spec sheet lists them at 40oz-in which calculates to around 1 foot-pound of torque for all 5 motors. I don't think this would be able to get me going very fast if at all. This is why I was looking into a bigger, more powerful motor. Like I said, I would hopefully be able to register this vehicle as something other than a bike so that I would have less limitations on this sort of thing. If necessary I would also be able to under-amp the motor so that it is less powerful. Also, if I need to stay under 20mph I could always just gear its maximum speed to be 20mph. 



Amberwolf said:


> As a side note, 12V12Ah batteries weigh around 9 pounds each. The 31Ah's I have are around 23 pounds each. I think the 20Ah were around 17 pounds each. Remember that to draw more current without damaging your batteries you need to have bigger ones, but you probably shouldn't get batteries that are bigger just for the sake of being bigger, unless you need that extra power capacity. Otherwise you will be carrying around a lot more weight, and it will cost you a lot more.


The batteries I plan on using are 100AH, 12V, weigh 50 pounds, and cost around 100 dollars a piece. I found them at a local battery manufacturer so they will be pretty inexpensive compared to other options. Also, this size of battery is their smallest deep cycle battery for any voltage. The reason why I was also looking for a bigger motor is because this machine could end up weighing around 550 pounds including me which might be too much for a 300watt motor. 



Amberwolf said:


> As for the bike itself, one bit of info is that the longer the bike is, the wider it needs to be to counter the force of a turn without tipping over. Having the heavy batteries and motor on there will help to counter that. I'd recommend putting the batteries as far to the front as you can manage. On my trike, they'll be directly over the front axle line, or immediately behind it. The motor will be under the seat.


I planned on having the bikes dimensions be around 7'x3' which should be wide enough to keep it from tipping over. I attached a picture to give a general shape of what I was thinking, the dimensions are a little bit off so disregard that. The shaping on the outside is my dream fiberglass body but that is definitely a long ways off. 

Thanks for all the input, it really helpful for me to see what problems I might potentially have.


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## Amberwolf (May 29, 2009)

ithinkidontknow said:


> I planned on taking the pedals off originally because it significantly simplifies the drivetrain. I am thinking down the road I will design a system to pedal an alternator to recharge the batteries. Ideally, I would be able to register this bike as something other than a bike. Also, keeping the pedals off allows me to keep from running into problems with having freewheeling gears like you .


That's true. See the other thread about the alternator thing.





> The other 5 motors that I have probably wont work for my project like I originally thought as they are extremely low torque fan motors. The spec sheet lists them at 40oz-in which calculates to around 1 foot-pound of torque for all 5 motors. I don't think this would be able to get me going very fast if at all. This is why I was looking into a bigger, more powerful motor.


Well, I didn't have much *starting* torque with them, but I sure got fast enough speeds out of them, when I used two pancake-style radiator fans (with no iron cores) and roller-skate wheels on their shafts as friction drive to the rearwheel tire, at 36V. Even bolted to a 4U rackmount faceplate 1/4" aluminum, with the airflow from the bike moving down the road, they got too hot to touch, but they never burned up in several months of using them. I *did* break a shaft on one, but that was almost certainly because of the sideloading of the thin shaft and pressure against it when I hit big bumps (very common on Phoenix road edges, which can't always be avoided due to traffic). 

If I remember right, I got near to 30MPH on a flat no-wind test run with my crappy well-used 3x 12V12Ah UPS-style gel-cels. (which were so well-used they only lasted me about 3 months of useful life for that project, and another month or so of partial use).

Not bad for a pair of PMDC no-iron-core radiator fan motors. 



> The batteries I plan on using are 100AH, 12V, weigh 50 pounds, and cost around 100 dollars a piece. I found them at a local battery manufacturer so they will be pretty inexpensive compared to other options. Also, this size of battery is their smallest deep cycle battery for any voltage. The reason why I was also looking for a bigger motor is because this machine could end up weighing around 550 pounds including me which might be too much for a 300watt motor.


Uh, yeah, that would be a bit much.  I can't imagine what shipping would cost for them, so it's good they're local!

$1 per Ah seems pretty good, though you will probably not get but half of that in actual energy output, since you'll be pulling it out really fast.




> I planned on having the bikes dimensions be around 7'x3' which should be wide enough to keep it from tipping over. I attached a picture to give a general shape of what I was thinking, the dimensions are a little bit off so disregard that.


Looks like a reasonable basic idea. Will it have suspension? (I'm just now working on my first suspended design that I'll actually be building, so I have little experience with suspension so far). 




> The shaping on the outside is my dream fiberglass body but that is definitely a long ways off.


For the moment, you can always use all those garbage signs people leave all over (often illegally) for advertising. They're made of coroplast, which is pretty tough stuff. Quite a number of cyclists have made partial or full fairings out of it!

Using sign pieces for it has the advantage of being free, since they are often found blown all over the roads and ditches after storms. If they're illegally put up, you might even get permission and encouragement from the city to go around and collect them! 



> Thanks for all the input, it really helpful for me to see what problems I might potentially have.


You're welcome--I didn't really have anyone pointing the way for the most part, other than the sites I found that had done what I was trying to do, most of which didn't have that much detail. Less than a handful of people had replied to my blog posts until recently (it's now about double that, I'd guess), so I didn't really get much feedback on my ideas, until I tried them out and failed in one way or another. 

With a low or zero budget, it's pretty tough on you when what you had planned turns out garbage, and you have to start over. 
________
CURVYQUEEN20


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## ithinkidontknow (May 14, 2009)

*Thought I would post this over here too.*

Quote:
Originally Posted by *Amberwolf*  
_They probably are similar. Your city codes are probably here at this site:
http://www.municode.com/Resources/co...asp?stateID=47

It might be a lot more complex than you imagine, depending on WA requirements for custom-built or modified vehicles. There are some states that don't like those at all, such as Ohio, and people have a really hard time ever getting those registered or allowed on the roads. There's even an ad here somewhere on the forum for a bike in Ohio (I think) that the person couldn't get them to register at all, so he's selling it since he can't use it.  
_

So I looked through the vehicle section on this website and found that it may be easy to register this as a "motor-driven cycle". This is technically any motorcycle, scooter or other vehicle powered by a motor which is under 5 horsepower! This is exactly where my project fits in! Also, if I follow all of these rules and am able to do this, then I have no restrictions on maximum speed (other than the speed limit) as long as I can keep up with the speed of traffic! Seems almost perfect to me.
Here are some of the rules:
-No person shall operate a motorcycle or motor-driven cycle not equipped with mirrors on the left and right sides of the handlebars which shall be so located as to give the operator a complete view of the street or alley for a distance of at least two hundred (200) feet to the rear of the motorcycle or motor-driven cycle.
-No person shall operate a motorcycle or motor-driven cycle which does not have a windshield unless he wears glasses, goggles, or a face shield of a type approved by the State Commission on Equipment. (RCW 46.37.530(1)(b))
-Every motorcycle and every motor-driven cycle shall have its head and tail lamps lighted whenever such vehicle is in motion upon a street or alley. (RCW 46.37.020)
-Every motorcycle and every motor-driven cycle shall be equipped with at least one (1) and not more than two (2) headlamps which shall comply with the requirements and limitations of this chapter. (RCW 46.37.040(2))

This does not look too bad! The only problem I can see now would be to get something like this registered with the department of motor vehicles. I've heard good stories from insurance companies on these sort of things though.

Anyone from Washington have any idea what I can expect? 







http://www.diyelectriccar.com/forums/editpost.php?do=editpost&p=122471


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