Use a Treadmill DC Drive Motor and PWM Speed Controller for powering tools


Step 4: Types of Treadmill Motors

Picture of Types of Treadmill Motors
I have seen 3 types of motors.

DC Permanent Magnet with PWM controller (Great for torque at all speeds).2 wires to the motor (Usually).

DC motor with Armature-voltage DC Motor Control. (Great for torque at all speeds).4 wires to the motor. 2 run to the shunt-field current , 2 run to the armature. Vary the voltage applied to the armature, vary the speed. Not all 4 wire motors are Armature Voltage controlled. Some have 2 wires that are part of a thermal protective circuit. The ones I have seen are usually both blue.

AC motors. (Probably not any better than the AC motor your'e thinking of replacing).Motors are running at a constant. Incorporates a special sliding pulley.Changing the belt speed is done manually-controlled with a cable that changes the size of the pulley's diameter. Larger motor pulley diameter faster belt speed, smaller pulley slower belt speed (I think).

The DC motors vary in size but most are Permanent Magnet,have brushes, a flywheel,and have either tapped holes or a bracket or flange welded to the case for mouting. They typically can range from 80-120VDC but as high as 260VDC. The HP's 1/2 to 3.5HP (treadmill duty rating), Upper end RPM 2500-6000, 5-20 Amps.

The Max RPM isn't as critical when you can adjust to any RPM within the range and keep a near constant torque.

You can reverse the direction on the DC motors by reversing the polarity. Simply swap the 2 motor wires (usually Black & White or Black & Red)at the terminals on the PWM circuit card. Remember if you reverse the direction of the motor you can't use the flywheel as it is. Because of left hand threads it could come off. Drill tap and set-screw the flywheel to the shaft
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jtcalamusa2 years ago
I have a motor from a treadmill that I got for free off Craigslist. It has four wires, red, black and 2 blues. It seems, from reading your article, that it has a thermal protection circuit based on the two blue wires. If I want to use this motor as part of a generator do I need to use these two blue wires? Thanks.
the two blue wires are thermal overload wires. you dont need them. loosen the one nut thats holding the wires in place and the overload slides out. now you could keep them in there and tie one blue wire to the red wire and apply power to the black and blue wire if you want to use the overheating function. personally i take it out cuz i never need it.
Which treadmills have you found work best for the conversion?

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