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120v Motorbike??? Answered

hey guys... so i managed to snag a 120v motor from a ryobi leaf blower... how would i need to go about making a battery pack for it? and how would i mount it??? i was thinking of relaying batteries with wire and tape.... but i DONT want it to be a bomb on wheels!!! XD and for the mount i was thinking of welding some bolts into the motor and then onto the bike near the sprocket.... even then.. how am i supposed to attach it to the axle to make the wheel spin?? weld in a rod or something i suppose?? i also made sure to grab the switch cause i dont feel like making one and it has three settings... off, 1(slow), 2(fast).


I was thinking that same thing about mounting it with a wheel of small dia. Pressed against the wheel..

I took robotics in 8th grade and that was 5 years ago and i forgot how to do the work to find power in watts... I have what i think are the two units i need.. V and Hz... But multiply or divide??? Or what? Its been too long.

Now my problems extend to the power source and wiring.. Now i know you said i need some sort of electric power throttle.... How bout a dimmer switch???

I dont really have the tools to be milling any steel for this but i may be able to swindle my old shop teach with some beef jerky... But i do have access to a dc stick welder that im good with using.. And i know more about what stick to weld with than i do anything about the motor.

Could i weld a sprocket to the output shaft and chain it to the bikes sprocket? Id definitely be welding up a cover for that...

This is what brought me to the conclusion of perm. mag.


Heres the best inside view i can get


I think its a perma mag DC


I am an ambitious and industrious person. Probably too so.

But yes i believe it does. It is a dc motor...
I know "i believe" isnt very assuring. But could i use those batteries they make for high powered RC planes and stuffs.??

Yes. Batteries exist. Even ones that are lightweight and powerful. There are even tutorials here showing you how to build batteries, by wiring together individual cells, to a pre-made BMS (battery management something?) board.


However, I think contemplating batteries is premature, when you do not even know how much power your motor wants, and at what voltage, and how much current.

I mentioned this in my previous reply, suggesting that you discover the electrical wants of your motor first; i.e. how much voltage (in volts), how much current (in amperes). The product of those two numbers is power (in watts).

Also consider looking at some of the existing electric bike instructables here, for to get an overview of how other people are solving this problem.

e.g. quick and dirty, and weak


e.g. more advanced, and expensive


Also im not worried about the weight. Its not anything im entering in a competition or anything.. I just want it to spin the axle on my wheel enough to get me to and from work xD

I think a good first step would be to figure out what kind of motor you have, and determine if it can run from DC (i.e. direct current) which is, you know, the kind of electricity batteries naturally produce.

I am guessing a leaf blower would have a universal motor,


or maybe a permanent magnet DC motor?


Both of those will work with DC power.

Another revelant question is: How much power (in watts) this motor can throughput? I think a typical sized motor, in terms of max rated power, for supplementing power to a bicycle, is about 200 to 2000 watts, or 0.2 to 2 horsepower, approximately. This guess is loosely based on projects I have seen described, on sites like Instructables, in the past.

I don't think ever seen one of these motor-modded bikes up close, in real life (IRL). Although I occasionally have seen (and heard) small engine (like from a "weed-whacker" string trimmer) powered bicycles, driving around on the streets and sidewalks.

Regarding mechanical power transmission, the usual, cheap, trick for this, is a small diameter wheel, or tube, mounted directly on the output shaft of the engine or motor. This wheel is then pressed agaist the bicycle's back tire somehow, and the mechanical advantage for this crude "transmission",


is just the ratio of the diameter of the back tire to the diameter of the little drive wheel on the motor's shaft.

Regarding batteries, I dunno. I think it would be easier to build a crude AC to DC converter first, and do some measurements with everything bolted to the lab bench, for to discover how much voltage and current, and thus power, the motor actually uses.

I mean, I think that would be better than just buying batteries based on complete guesswork, about how much current capacity (in ampere*hours) you think the bike will need.

Some kind of electrical power throttling, like a big PWM (pulse width modulation) driver, might be wanted too. The old golf carts, like from 30 years ago, used something like a rheostat, big resistors, switched in or out, as a way to limit current to the motor when starting, i.e. getting the cart rolling slowly.

120 V in batteries? thats ambitious. sounds like a lot of weight. check first whether this is a universal motor capable of running on DC