<$1k DIY Neighborhood Electric Motorcycle

[captainslug]

I'm abandoning this motor in favor of one that includes a gear reduction.
It overheated enough to dislodge the epoxy from the rotor, and the inside is coated with soot.

[Christ]

Originally Posted by captainslug

I'm abandoning this motor in favor of one that includes a gear reduction.
It overheated enough to dislodge the epoxy from the rotor, and the inside is coated with soot.

Can it be salvaged and used for something else? (After being cleaned up/rebuilt, obviously.)

What motor will you go with now?

Can we have pics of the inside of the current (toasty) motor?

[nubie]

Going beefier?

Is there room for a motor with a larger case diameter, that will increase the torque (at the cost of top RPM, but that shouldn't matter) without increasing the friction through gear reduction.

I am guessing that a geared motor will have a planetary set in the the output end, I would also think that it needs lubrication of some sort.

I wish there was an elegant way to do this without the added friction of additional gears, just straight from the motor to the wheel, but I figure cost is an issue, as well as packaging. (oh yeah, and the freewheel adapter, don't suppose that could be incorporated on the motor shaft?)

Not being judgmental, just curious on your choices. If I never ask then I will never know (I may be too curious for my own good though.)

[captainslug]

Originally Posted by Christ

Can it be salvaged and used for something else? (After being cleaned up/rebuilt, obviously.)

It's not completely destroyed, but it came close to irrecoverably melting the brush assembly.
Because of how hot it got I wouldn't try to use it for anything that doesn't include a current limiting circuit or temperature cut-off.

The tentative plan is to go with one or two of these. MY1020Z3

Which I should be able to add a freewheel adapter to without too much work. I've ordered one for testing, and depending on the results I may order a second one and wire them in parallel for speed or series for torque.

[nubie]

Cool, not a planetary system at all.

I like the looks of that motor.

[Christ]

Originally Posted by nubie

Cool, not a planetary system at all.

I like the looks of that motor.

Reminds me of Mini Hy-Tork starters. Sweet look, though. Hope they work for you.

[captainslug]

I've made a ton of progress since the last update, but haven't had a camera handy to record any of the specifics. Expect a large update before this weekend.

[captainslug]

Here's everything I've done in the past month. I apologize for not being able to take in-progress shots, but my camera took an accidental vacation in China because my boss mistook it for his.

+ I bought a 5/8" ID steel freewheel adapter from Staton Inc.,
+ I used the lathe to bore the ID out to match the motor axle size.
+ The #40 double-D-bore sprocket included with the motor was ground down to make a washer.
+ Washer was then TIG welded onto the freewheel adapter.
+ I drilled the hole pattern into the #35 sprockets, then used a bolt to chuck in the lathe so I could cut out the large center hole.
+ I made a motor-mount plate out of 1/4" polycarbonate, and end brackets out of 1" aluminum square tube.


The sprockets are bolted onto the opposite sides freewheels so I could attach the motors to the motor mount plate at an offset. This allowed me to overlap the gear case of the top motor over the cover of the lower motor.

See below image showing where I had to grind both.

Doing this save me just enough space so that I had more than enough clearance between the frame and the top side of the chain.

I also drilled out and cut square notches in the mounting holes.
I thought I was going to have to offset the brushes 90 degrees to reverse the motors, but it turns out the motors spin the right way around when stock.
Wasted effort on my part, but at least I had the option of reversing them later on.

The problem I have now is that the sprocket on the lower motor isn't engaging enough teeth and slips on the chain. I may have to move the upper motor to the swing arm, or remount the lower motor after rotating the gear box position.

Left to do
1. Fix chain slip
2. Make new brake light
3. Make new turn signals (front and back)
4. Record a video for everyone that has been nagging me to

[Tango Charlie]

Awesome, top notch work (as usual!), captainslug.
Chain slippage was my first thought when I scrolled down on the first pic. Would it work to put an idler between the two motors, so that the chain is pushed into the gap between them? If so, it looks like you may be able to get 3 or 4 more teeth engaged on that lower drive gear.

[Christ]

Is there any way to re-clock the lower motor, so that the whole thing is turned 90* clockwise from where it currently is?

What about turning the upper motor 90* CCW?

Other than that, I can only see one other option right away, (without really thinking into it): Flip the rear tensioner over, so it's above the rear sprocket, and add another tensioner from the rear frame section to hold the chain so it makes at least 45* of contact w/ the lower motor's sprocket.