FS: variable speed 90VDC gear motors
Login to Your Account
Likes Likes:  0
Results 1 to 1 of 1
  1. #1
    Join Date
    Nov 2006
    Southern California
    Post Thanks / Like
    Likes (Given)
    Likes (Received)

    Default FS: variable speed 90VDC gear motors

    I picked these up a while back for a rotary welding table project but never ended building it. These are used but have not been run much. The previous application had them running only intermittently.

    Motor Specs:

    90VDC 0.75A permanent magnet DC motor
    150 in-lbs continuous duty torque
    17.5 RPM (max speed)
    Made in USA

    The motor has a disc on the back underneath the red cap with 6 inset magnets (or metal disks). Above which is a encapsulated circuit board with two components on it. I suspect they are hall effect sensors. The connectors were labeled 5VDC, A, B, GND as marked from the mating PCBA. I tested it out with a 5VDC power supply and a volt meter. The A & B contacts look to be open collector quadrature outputs. I used 5K pullup resistors on A and B and they appear to work fine. If those are really 6 inserts, that would yield 24 counts per motor revolution. If the motor gearhead is 100:1 reduction (which I suspect since these motor are usually 1750 RPM or so), that yields 2400 counts per revolution of the output of the gearbox. I have not measured the resolution this I cannot guarantee my math is perfectly accurate.

    The encoders will help with wider speed range if your controller supports it. But you do not need to use them. I did hooked the motors up to a variable speed DC drive (no encoders) and they ran nice and quiet. I was able to get a low speed of 0.75 rpm out of them. Usually I pick up low-cost new or used Minaric, KB Electronics or Dart motor speed controllers off of Ebay to drive motors like these ones.


    I checked and one of these will fit into a USPS Priority Mail large flat rate box.

    $45 each + shipping, US sales only.

Tags for this Thread


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts