where to buy electric motors from

[atcosi]

I wanted to install a treadmill motor on a treadmill that was not designed with one, and I wanted to know where I can find online retailers. After a search on the net, I found several comments about the type of motor required. A DC motor about 2-3 hp, taking 80-260V DC. I am a little clueless about such things as speed control, the right kind of DC motor, how to convert speed to torque with gears and if that's necessary, finding the right power supply, how to install it on the treadmill, and any other issue I haven't thought of. Ideally I would like a product that solves the problem while costing much less than buying a new treadmill, say $AU200 or less.

For future reference I would like to know sites where I can buy electrical and mechanical engineering products.

[JohnS_AZ]

This is one of my favorite surplus places on line, however it's in the US. They do have quite a few motors that would do the job however...

I'd go to the thrift store and buy a use electric treadmill.

https://www.surpluscenter.com/

[GeoffS]

I'd suggest eBay and look for someone getting rid of a treadmill. Motors by themselves seldom come up (this is eBay Australia)

I'd recently been looking for a treadmill style DC motor to put in a lathe but couldn't find anything suitable/affordable.

[Simon]

yea, sounds like an awful lot of work, you'd be better just getting a motorized tread mill.

[Mechatrommer]

most electric motors are speced in its torque T (Nm lb.ft etc) or power P (hp, watt etc). for ideal system (no loss):

P = Fv (P in watt, F kg.g force, v speed m/s) or in rotational system its
P = pi.T.rpm/30

if my math is correct in SI unit, for imperial unit, some reference... http://www.epi-eng.com/piston_engine_technology/power_and_torque.htm
but more toward mechanical power stuff there. but mech power should be the whats so called electrical power... i guess.
so expect higher motor power when buying to compensate for energy loss (electrical and mechanical).

for gearing, i'll try to sum it up as simple as possible. slowing down gears (smaller to bigger) means increasing pushing force, and vice versa ie increasing speed gear will reduce its circumferal/tangential force capability, but the torque (F.r) and power are still the same for lossless system which is of course do not exists.

electrical power on the other hand... well:
P = V.I (what else?)