Golf cart based electric motorcycle build.

[MetroMPG]

Originally Posted by woodsmith

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

Impressed!

[Ryland]

My motor is going to be off set to the right side by about 7 inches, this gives me enough room on the left side for another battery next to the motor.
Your splines are impressive for being cut free hand, I was going to try to make splines on the mill with the corner of and end cutter but it was not the correct angle, it might have worked for a while but I want mine to be as exact as possible.
I also wanted something that, if it all works out correctly I can make more for anyone who wants one, after all most of the work is in figuring out how to do it the 1st time.

[Ryland]

I haven't done much work on this project in recent months but I'm starting up again now that the weather is getting warmer it's more comfortable being in an unheated work space.
Current part that I am working on is making an attachment ring for the dust boot that keeps dust out of the drive shaft, I'm using the stock dust boot from the CX500 motorcycle but it attached to the engine with a collar that was pressed in to the gas engine, this is not going to work for me so I'm going to make what looks like a very thin spool out of some 2" aluminum pipe to create a flange that the dust boot can then slip over, I had a number of people suggest that I not bother with a part like this, but over time dust and sand getting in to the UV joint will wear it out and I would like this to be as reliable as possible.
The milling machine at my parents house is also in full working order so I can mill basic parts on my own now, this should be helpful in making the battery rack and the last part of the motor mount.
For the battery rack I'm thinking I'll have a center solid rib that supports the batteries and connects to the frame where the engine did, giving strength to the frame, then box it off a bit, have what looks almost like a skid plate between the batteries and the front tire and have it wrap under the batteries and motor, if I set the batteries low enough there ends up being an empty cavity under the motor, this seems like a good space for the speed controller, at some point this week I hope to do a card board mock up of the battery rack and batteries to see how it will really fit together, I'll take photos at that point.
I was also reading about motor options, there are some nice 3 phase brush-less motors out there that will bolt right on, peek horse power of 50hp would match the stock engine altho a 72v motor from a GEM should also be able to handle a momentary peek of nearly 50hp as well, so either way, if I am not happy with the $200 3hp motor I have, a more powerful motor will bolt right on.

[MetroMPG]

Ryland - any chance you're taking pictures of the work as you go?

[bennelson]

Pardon my ignorance...

Is there any sort of gear reduction between the driveshaft and the rear wheel? If so, what kind of ratio?

On my chain-driven electric motorcycle, I am using a 6:1 gear ratio to keep the motor from working too hard. (It's a 48V system.)

A friend of mine has a drive-shaft cycle that he has been playing around with as an electric conversion, but he's been having issues with pulling too many amps.

I would imagine that higher voltage would help with all of that, but I was just wondering what the "gearing" difference is between a chain/belt drive and a driveshaft.

[Ryland]

Originally Posted by MetroMPG

Ryland - any chance you're taking pictures of the work as you go?

Yes I'm taking photos, mostly with my cell phone, but a few with a borrowed camera as well, I also figure once I get it all done I'll take it apart and take photos from start to finish, or get another motorcycle and build a 2nd electric motorcycle.

Ben, no gear reduction, the stock gear reduction on the drive shaft is around 3.09 to 1 if I remember correctly and that is higher then I would want if I was starting from scratch, but that is the other reason that I'm using a series wound motor is that they have better low end torque and I do share that same worry about drawing to many amps, but like you said, a 72v motor and controller should help, or at some point shell out the money and get a 144v motor and controller, there are only a few that I have seen and they cost a bit but they are an option and would bolt right on.

[Ryland]

I'm almost done building the battery box for my motorcycle, it's taking a little while because I had other projects to take care of over the summer, the first version is made out of steel because I can weld steel and it's cheaper then aluminum.
I also picked up a used Altrax speed controller, 48v 400amp controller, should be good enough to get it on the road and see what stock golf cart parts can do.

In other news I met a guy near here who is building an electric Honda Goldwing, he's also using an EZ-Go golf cart motor, of course he had the same issue I had with needing to connect an open face motor that has a female splined stub instead of a normal output shaft, as it turns out, Honda used the same spline on the output shaft from the transmission for the Goldwing as the did on the CX500, the only thing that is not the same is the Goldwing shaft is held in to the swing arm UV joint with a snap ring where the CX 500 uses a 6mm bolt that locks in to a grove in the end of the shaft so it can't pull out, but as luck would have it, that snap ring on the gold wing a redundant part because the shaft inside of the goldwing swing arm has more support.
So just a few minutes ago I get a phone call from this new friend with the Goldwing, telling me he has his motor bolted up and is working on placing batteries, motor runs, rear wheel spins and he's hoping to have something on the road latter this week, max GVW of the gold wing is just over 1,000 pounds, so even with a frame full of lead acid batteries his motorcycle will be 100's of pounds under it's max weight, mine will be pushing it's max weight but should still be under it.

[Ryland]

Photos! sorry for the low quality, my cell phone camera isn't the best after 4 years of being in my pocket and getting stepped on a few times.



Here is the battery box, it's almost done other then two steel plate tabs that go on the top, center, that bolt to the frame, up under the gas tank, these two plates will be 3.5" apart and give space for battery cables to come up from the lower batteries, they are next on the list of things to weld.



Here is how the motor looks in the battery box, almost enough space under the motor for the speed controller but not quite... might put the DC to DC converter under there or just a spot for storage? not sure yet.




Here is a photo of the test fit of the adapter shaft that I designed fitted in to a 1978 Honda Goldwing... Nothing else from my motorcycle design swapped over other then the shaft but the shaft is also the hardest part in my mind to make.

[mechman600]

Glad to see you are back at it! I can't wait to see the final results. I really really want to convert a motorcycle sooner than later. Actually, I want to convert lots of vehicles but I have limited space and a wife who doesn't like seeing "junk" lying around, whatever that means....

Anyway, I'm sure what you learn doing this project will make it easier for many others (including myself) in the future.

[Ryland]

Quick update!
I have the battery box built, all of the tabs for bolting it to the frame are done, welded in place and drilled so it bolts to the frame in the same way as the stock gasoline engine did.

The battery box is designed to hold 6 6v Trojen T105 golf cart batteries, yesterday I spent the afternoon trying out routes for the battery cables, drilling holes and installing grommets to protect the cables from being cut on the steel of the battery box, I also found it to be a tight fit but that right under the electric motor there is just enough space for the Alltrax speed controller to live but that it was to tight of a fit to wire the speed controller to the closer set of lugs on the motor so I had to use 13" long 2/0 battery cables to connect the motor to the speed controller, I wanted to use the 9" battery cables but it would have been a mess to get fasteners on and the chance of something shifting slightly and shorting out increased.

One of the local parts stores sells 2/0 cables that are 9" 10" 13" and 15" longs, the type of cables that have a lug with a flat drilled end that gets bolted to a stud, because my battery rack is two layers of batteries the 15" cable was not long enough! so I ordered from McMaster Carr a 20" and a 30" cable, one to connect the upper bank to the lower bank and one cable to connect the upper bank to the speed controller.

I thought about ordering up bulk cable and crimp on ends then borrowing a crimper from a friend of mine but I wanted to see if I could do this with as many off the shelf parts as possible and while it's true that some auto part stores can make battery cables for you and most shops that service heavy trucks have crimping tools to make battery cables, I figure if I used parts that every auto part store would sell you along with some that you can easily order then I'd know it's possible to just put those battery cables on a shopping list with custom made cables being an alternative option.

Pretty much everything else looks like it will be able to be put on a shopping list as well! the battery box of course will have to be cut out of plate steel or aluminum and welded up, but once you have a pattern I think it could be done in a few hours or less!

As it is, because the speed controller is in the battery box next to the motor, I don't have to build any other brackets that bolt on to the frame of the motorcycle! this frame I've been using to test fit doesn't even have a title so I figure it will take about 3 hours for two people to swap everything over to a different motorcycle and have that motorcycle going down the road! I think there will even be space on the front of the battery box to bolt on the Noco charger (4 bank charger, good for 12, 24, 36 or 48v) so right now the only thing that is keeping this motorcycle off the road is the non working front brake, the flat rear tire and the battery cables that showed up on my door step 10 minutes ago! lucky for me my friends motorcycle shop is on the way to my parents house where this electric motorcycle project is taking place, so I'll pick up the rear tube and inquire about front brake parts!