Golf cart based electric motorcycle build.

[Ryland]

I haven't posted an update here in a while but things are still moving along, mostly I've been busy with other projects.
The 3rd and final part for adapting the golf cart motor to the motorcycle is finished! the 3.5" splined shaft that connect the drive end of the motor to the drive shaft of the motorcycle, my brother managed to make 7 of them out of a bar of P20 tool steel that I bought, he said the CNC program to make each one was taking nearly 3 hours total for each shaft, mostly due to the splines and the fact that P20 tool steel is tough stuff, it does produce a nice finish and they fit nicely in to their mating parts.
I only have one of each of the plates and bearing holders that hold the motor and hold the shaft and it's a bit beat up from changes so I now need to do a test fit of everything and make any final adjustments in my measurements then have and get a final drawing done so a small production run of the other parts can be done.
If I get enough time I might even try putting together something that I can ride, I've been busy enough that I still have the Altrax 7265 speed controller sitting around instead of having it installed in my car.

[bennelson]

We demand to see photos as soon as you have them!

[bennelson]

Parts are looking good!

[Nigel2112]

Hey Ryland! That's an old CX500c isn't it?!
I owned one of those babies.
It's got a nice tough chassis that can take lots of batteries. Can't wait to see what you do with it.

[Scimitar]

Nice to see an old CX500 with a new lease of life. I think at one point, every courier in London had one - long lived and could take a beating day in, day out. The cycle parts are well up to heavy loading, so have no worries about the battery weight, just make sure the frame's got no cracking and replace the swingarm and wheel bearings as a matter of course.

[Nigel2112]

Its successor, the VT500 was quirky but just as bulletproof.

[Ryland]

The swing arm and frame look to be solid, I'll most likely be using this frame as a test bed anyway, as it's missing the speedometer, front brakes need alot of work, seat is shot, turn signals are missing and I can get another bike just like it for $200 or less with a bad engine off craigslist.
The big hicup I've run in to is I was told that the 3.5" shaft in the photo could cost $300-400 each if I wanted more of them made, it will still mean that this will be a very cost effective motorcycle to build as everything else you need to build one is cheap to buy but I think that a single high priced part can turn alot of people away and it's going to push the total price to build one even closer to that $1,500 mark I was hoping to stay under as the motor adapter "kit" might come out to cost $600-700 at this point, another $300 for a used motor and controller from a golf cart shop, $200 for the motorcycle, leaving only $300 for batteries, battery rack, cables and hard ware.

[Clev]

Originally Posted by Ryland

The big hicup I've run in to is I was told that the 3.5" shaft in the photo could cost $300-400 each if I wanted more of them made,

Ouch. Seems a little high, doesn't it? If you decide to make this a kit, you'd probably be able to find a shop that would do them in quantity for half that.

[Ryland]

Originally Posted by Clev

Ouch. Seems a little high, doesn't it? If you decide to make this a kit, you'd probably be able to find a shop that would do them in quantity for half that.

The cost is high because the steel that is being used is really tough and a carbide cutter had to be used instead of a high speed steel cutter, with that a single cutter can only make two shafts before it wears out, it also takes 3 hours to make each shaft on a CNC machine due to the splines, if the shaft was longer and there was more room to over run the cutter then it could be done differently and quicker.

[woodsmith]

I notice that you are direct driving the drive shaft without the gear box. How are you placing the motor? Off to one side or are you centralising it somehow?
I am building a reverse trike using a BMW K100 transmission complete.


The input shaft is 90mm off centre but the shaft would be 150mm off centre and higher then my prefered motor mount. I am going to use a short shaft but a nice looking one.



The trans gives me a slightly under geared drive for what I wanted, 1.61:1 top gear with a 2.81:1 final drive giving 4.52:1, for my first choice 12" motor so I have decided to use a smaller but hopefully faster 9" motor.


Those shafts look great, though costly!

I was using a similar motor but not having access to anything but a small lathe I had to find a simpler way to make splines.

Turned a blank on the lathe.


Marked out the edges of the splines.


Cut the splines with a 4 1/2" disc cutter freehand.


Fits a treat. (notice the wooden DE bearing cap)


I made three of them in the process of working out how to use the other end.
I settled on this one with a support bearing on the outer end.
I even had to chisel the keyway out with a small cold chisel.


I also used a square of aluminium plate for the DE.



It now drives my tractor.