# Reverse a Treadmill motor



## major (Apr 4, 2008)

Inquisitor720 said:


> I did a search on the forum and found three articles about changing rotation, but it was on big honking forklift motors. I have two DC motors that I think came out of treadmills. They’re in the 2.5 Hp range. One says it meant to turn C.W. and the other says C.C.W. I tried applying about a tenth of the rated voltage in the reverse direction and it seems to run just as freely as in the correct direction. What I’d like to know is:
> 
> 1. Will it hurt the motor to run it in the reverse direction so I can back up the vehicle without having to have a gear box?
> 2. Or is it just less efficient?
> ...


1. No.

2. No.

3. Just search for basic electric motor theory. Most articles will have diagrams showing the field direction, current and force. Like this: http://www.reliance.com/mtr/mtrthrmn.htm


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## shortbus (Sep 27, 2011)

Most treadmill motors have offset brushes to keep sparking at a minimum and this also keeps them from running in reverse. But by modifying the brush holder position they can be reversed.


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