One additonal thought, based on post #1, is that if the presently fitted drive motor is a DC motor, and the complaint is "not quite enough torque" because the DC supply is "a bit weak", that a more powerful variable DC supply can easily be the cheapest solution. An isolated triac power controller scheme can cost a lot less than a suitable transformer, and be a smaller package as well.

 

A good cheap source could be to look at one of the TM (treadmill)) motors and MC2100 controllers, they operate on 120vac and are isolated PWM controlled.
Typical DC motors are 1.5 to 3hp rated.

 

One concern about 'treadmill motors" is what I see as a serious lack of discarded treadmills. In the past year I have only seen one of them. I imagine that the purchase price of such a motor will be close to the price of a similar rated indusction motor. Not Cheap!!

 

I check the local market sites, many advirtised not working "free for removal".

 

I check the local market sites, many advirtised not working "free for removal".

OK, MAX! I had not considered that option.
What do you know about what is the most common failure?? That would be useful to know. Certainly a treadmill is a heavy item, although I am sure that they separate into sections that are easier to handle. At least that is my guess..

 

I found they are discarded for many fault causes, and expensive to repair, motors are generally intact, either the motor controlller or just wear and tear of the main unit is the cause, I am just interested in motor/controller and scrap the rest.

 

I found they are discarded for many fault causes, and expensive to repair, motors are generally intact, either the motor controlller or just wear and tear of the main unit is the cause, I am just interested in motor/controller and scrap the rest.

That is the case with pretty much everything nowadays. You see a "chip" and LCD controlling electric kettle! What was wrong with thermostat that lasted too long? The manufacturers know that these are not generic things and once they break, whether it is a $1500 treadmill, a washing machine, or a kettle, you will be either forced to buy a new one (instead of reparing) or seeing no sense in buying part that costs half of the whole thing. These are not paranoid thoughts, they are very well-documented. I strongly recommend Veritasium YT channel. Entertaining and informative. The dude is a professor BTW, so no sloppy math in his contents
This is why we can't have nice things
Planned Obsolescence documentary - The Light Bulb Conspiracy (2010) RENT / BUY TO MORE GREAT WORK