New Guy.. With So Many Ideas...

[Smurf]

Hello everyone, first time kart builder here. I've been researching for about two hundred total hours now, and this is the place I need to be.

My mind wanders, a lot. It goes beyond the typical boundaries, which in some cases can be good, I assume. I thought I had a grasp on all this technology (I'm focusing on DC electric driven trikes) and now that I've researched more, I realize I have no clue.

Random thought.. I saw the YouTube video of the kart with three outrunner motors inline, and it moved quite well for having smaller (and/or cheaper) motors. Would there be any benefit to mounting multiple outrunners outside of a small Geo-sized flywheel, with the flywheel having a smaller sprocket mounted on it, connecting to the axle sprocket? Almost a planetary type design. Wouldn't that keep some perpetual motion, lessening the juice requirements from the batteries?

And that's how my mind works folks, I'm sure I'll fit riiiiight in

 

[souperman000]

welcome, just to calrify...you want to use 3 engines? If you do, you will need to have them all synced up together

 

[Smurf]

That's the loose idea that I had floating around. I'm no where near a rocket scientist by any means, but I could see how that could conceptually work.

 

[flowerman]

hmm still kinda confused

 

[B man]

Ok. four motors. and there all connected to a small fly wheel and then the fly wheel has a sprocket to the drive sprocket. but wouldn't two have to spin counter clock wise to the other two right? or probably not.

 

[anderkart]

Wouldn't that keep some perpetual motion, lessening the juice requirements from the batteries?

Yes, the inertia from a heavy flywheel should lower the motor amp draw while climbing small hills, but it would also come with the side effect of increasing it under acceleration. So overall any advantages would depend on how and where you ride. And unless you used some type of clutch, this flywheel-effect would also put more strain on your brakes.

 

[oldbikerarlo]

Your thinking outside the box, I like it

 

[Smurf]

The flywheel idea would use anywhere from three to six smaller motors, with the "keep rebuilding it til it works" strategy. And yes, "thinking outside the box" is my specialty. I thought it was something that could be tweaked to a workable idea.

Due to the local laws around here, with "powered bicycles" only defining the 49cc-or-less gas variety, my plan is to start basic with a regular bicycle. The officer I spoke to said "If it looks like a bike, you're okay", so I took that to mean "Push the envelope as far as you want until they get mad."

The town I live in is under 20,000 people, mostly flat but one hellacious hill on my ~5 mile round trip commute to work. The first build will be a bicycle that is pedal-power up to 10mph or so, then flip on the electric to boost to 25, 30mph. By taking the initial acceleration out of the equation, I figure to save some juice there, while forcing myself to keep the ability to pedal for legal reasons.

Anyone have any thoughts on where I should start my search for components? Recommendations on wattage, voltage (I was thinking 24v), batteries?

 

[Smurf]

Ok, I actually think I have a relatively solid plan of action here.. I realize this is a kart forum, but I'm using very similar parts for an electric bicycle. Anyone care to "double check" my work please?

I'd be asking you to confirm the components will work together, that the gear ratios would give me the result I'm looking for, make sure I haven't forgotten or miscalculated anything.

 

[fowler]

i rekon your loss will be more that your gain when it comes to power useage
friction is a ***** thats why perpetual motion is impossible
also i think reather than helping u in tough situations it would hinder
as the drive line slows the fly wheel would be forced to slow and keeping that extra heavy item spinning would require alot of juice

like if u fill a car with bricks
it will roll for longer as it weights much more but u will use much more fuel getting to a speed that allows u to use that frre motion

i do see it working as a gear reduction for alot of small motors to run in sync at high rmp lower load
rather than looking for a heavy fly wheel to extend the free wheeling run look for a super light one to act purely as a gear to reduce down the small motors

 

[Smurf]

Would a 2600RPM 24V 750W motor, 36V 1000W controller, four 12V 9aH 5 lb batteries (wired as dual 24V) work?

And with that 2600RPM, using a
20T on the motor to a
44T (approx) jackshaft-in,
19T jackshaft-out to a
55T (approx) sprocket
gives me a 6.37:1 overall gear ratio and 408RPM at the end? Then, using a 26" bicycle rim, would give me 31.55mph?

And the two strings of 24V (9aH each, 18aH per string) batteries would yield
[[18aH / 750W, x 24V = 0.576 hours] x 2 strings] hopefully 1.152 hours of runtime? I realize there are 'losses' along the way, and that would be 100% charge-to-discharge, but with pedal power until 10mph would this be likely to achieve 20mph average for a 7 mile daily round trip?

All info is greatly appreciated!