Golf cart based electric motorcycle build.

[Ryland]

Originally Posted by mechman600

The engine you pulled out of your Honda is a stressed member, an integral part of the frame/chassis.

Thanks for the tip, as others might not realize that and I forgot to say something already.
The battery rack is going to bolt up to those engine mounting points, I don't have a set design for the rack yet, but I plan to make sure it's ridged enough to stiffen the frame, currently trying to figure out how to get some braces to go from the head tube to the rear engine mounts without getting in the way of the batteries, I think if I use some aluminum plate that goes both between the batteries and under them it will be stiff enough as it will create an upside down "T", however I do it I realize it has to act as a stressed member as well, that is however part of why I chose this bike, no cutting of the frame and no welding of the frame, as that is where you create brittle areas that crack later on.

[TomEV]

Looks like an interesting project! I'd do a bit more research before committing to 2.85:1. Most of the motorcycles in the EV album seem to run at least 4:1 - many are around 5:1. Similar motorcycles (shaft drive) seem to universally use a pillow block/aux shaft reduction setup.

With the Citicar / Comutacar, you may have noticed a significant difference in speeds with the two normally available differential ratios. Comutacar/Dana at 5.17:1 are somewhat faster but don't accelerate as well as the Citicar/Terrell 7.125:1. At least for the C-car application, I'd pick something closer to 6:1 (happy medium between speed and acceleration).

Let us know how it goes...

[Ryland]

Originally Posted by TomEV

Looks like an interesting project! I'd do a bit more research before committing to 2.85:1. Most of the motorcycles in the EV album seem to run at least 4:1 - many are around 5:1. Similar motorcycles (shaft drive) seem to universally use a pillow block/aux shaft reduction setup.

I noticed that they tend to use a reduction between the motor and the shaft, but they also all tend to use the Etek motor as well and that is a low torque motor that likes to run at higher speeds, my motor is said to top out at around 2,000 or a bit higher, bump the voltage up (like I plan to do) and you will get a bit more top end speed out of it, it's also designed to power a 1,200 pound 4 wheeled cart with wide tires on grass with 2-4 people in it, not a 600 pound motorcycle on pavement with silica rubber touring tires and a single person, I agree that I might be pushing what the motor can handle but I'd like to keep it simple and I figure with the gear ratio that I have I'll have to add a heavy duty controller to handle the high amps needed to start from a dead stop.

[TomEV]

It looks similar to the motor in your Comutacar - 2000 rpm would be approximately 25 mph which is about where the C-car motor (at least the stock GE motors at 48v) starts to lose torque. But it should do at least 3,500 with no problems.

You're probably right - at 600 pounds the motor won't be working too hard. What kind of controller do you have in mind?

[Ryland]

I still need to look in to my controller options, but if I remember correctly there is a 400amp and a 600amp alltrax that work with my setup and voltage, I think that the 600 amp controller would be over kill, but it would allow me to see what the motor peeks at, then swap to a smaller controller and put the 600amp in my Comuta-car as I still have the relay based controller in there.
My goal is to have this motor, when it hits 2,000rpm for the bike to be going about 50-55mph, I know it's asking alot of this motor, so there are some things that I'll just have to wait and see about.

Originally Posted by TomEV

It looks similar to the motor in your Comutacar - 2000 rpm would be approximately 25 mph which is about where the C-car motor (at least the stock GE motors at 48v) starts to lose torque. But it should do at least 3,500 with no problems.

You're probably right - at 600 pounds the motor won't be working too hard. What kind of controller do you have in mind?

[bennelson]

My motorcycle uses an Alltrax 300 amp programmable "AXE" controller.

It is the 24-48V model. When I bought it, I was really split on if I should get the 24-48 or the 48-72V model. 48V has been good, but 72 would be even more fun.

300 amps has been plenty for me.

My cycle is designed for a 45 mph top speed, and uses about a 5 to 1 gear ratio (chain and sprockets) with an Etek motor. I could go with a faster (more amperage required) gear ratio, but that would also hurt acceleration, and I don't think the Etek would love it.

For something like a series wound motor to a driveshaft, higher voltage and amperage controller is probably a good idea.

[TomEV]

With my Citicar (older 3.5 hp GE motor - Alltrax 400 amp 48 volt setup) it would pull just over 400 amps for about 1 second, then start to draw less power as the motor sped up. Even flooring it at a rolling 5 mph the GE 3.5 didn't want to draw more than 350 amps or so.

I now have an Alltrax 7245 (72 volt, 450 amp controller but at 48 volts for now) and it uses the same amount of power at 48 volts - just over 400 amps for the brief time the motor is turning very slowly.

My guess is that the amperage may be limited by the relatively small brush wires in the motor (two per brush) - just about every thing else is heavy duty. In my case a higher amperage controller was somewhat overkill.

I'd imagine your golf cart motor won't draw more than about 450 to 500 amps, particularly because of the low weight.

[adamj12b]

Your on ecomodder, Home of the Open Source Cougar Controller. Y not use one of those?

It will handle 500A and all the way to 144V. You can use any voltage you want with it between 0 and 144.

For the cost of it, you will be less then the alltrax controller and have far more options to play with for optimal performance.

-Adam

[bennelson]

My car has a Cougar controller, my motorcycle has an Alltrax, and my friend Chris is building a drive-shaft cycle with a Cougar controller (700 amp version!)

The additional voltage of the Cougar isn't a huge help on a cycle, because cycles are typically lower voltage than cars, just because of how many batteries you can physically fit.

I remember Ryland mentioning the idea a while back of doing kits or just building EV cycles for other people. A name-brand controller may help buyers being more accepting of it, especially having a warranty. I did have a problem once with the Alltrax controller (replaced for free under warranty - their fault - manufacturing defect) and a problem with my Cougar controller (my fault - I screwed up - I had to fix it)

On Chris' EV cycle, we may try to go with a fairly high pack voltage - which will make the cycle INSANELY fun!

In short, I think a stock Alltrax or Curtis would be better for turn-key, semi-mass produced cycles, and the Cougar better for Custom/Fun/Special cycles.

One thing important on an EV cycle is that you have adjustments for your controller throttle response!!!!

[Ryland]

I haven't had time to read up on the home built speed controller, at this time I would like to stick with off the shelf parts, mostly so when someone sees my motorcycle and asks if I can build one for them, or if they can build one for them self, I can give them a parts list and keep it simple.
So far most of my time has been spent on part design for parts that can be mass produced, I might have 40-50 hours in to this project so far but when I go to build my 2nd one I'll be at this same mile marker after only 3-5 hours and would like to be able to build one from start to finish in a weekend.
My brother who is helping with the CNC made parts has other projects at school right now and I have alot of projects at work right now so I don't see much progress for the next month, altho I do plan to start on the battery rack soon, thinking welded aluminum plate, altho that is going to require me to set my welder up for aluminum, if I can I want to make the battery boxes large enough for foam insulation to help keep the batteries warm.