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View Full Version : Wiper Motors - Are they Reversable?



Supario
11-03-2006, 06:12 PM
Hi,

I'm planning to get two autorickshaw wiper motors for the drive of my robot. However I cant afford to have the motors spin at different speeds when going forwards and backwards. Is there any way of telling if a wiper motor (model, number of wires etc) is reversable or not without actually rigging it up and measuring the speed?

Wiper motors arent ideal for robotics applications because of the high current consumption, bulk, worm gearing (no coasting) and inefficiency, but there doesnt seem to be any better option. If anyone knows of any better gearmotors that can generate around 0.75 Nm @ 100 - 150 rpm that can be bought / ordered from somewhere in India, please let me know.

Thanks,
Supario

docel
11-04-2006, 01:07 AM
Hi Supario!
Wiper motor is just like any other DC motor and CAN be reversed. The need does not arise since the O/P shaft does a to-and-fro movement.

Supario
11-04-2006, 04:04 PM
Hi,

The thing is that I read that some wiper motors dont spin with the same speed backwards and forwards, something to do with the angle of the brushes. The links are here.

http://groups.google.com/group/comp.robotics.misc/browse_thread/thread/38cae2a9fe7262d2/f616c0fc288ccc15?lnk=gst&q=wiper+motor+reversible&rnum=2#f616c0fc288ccc15
http://pergatory.mit.edu/2.007/kit/actuator/fordmtr/fordmtr.html

docel
11-05-2006, 05:31 PM
Motors are generally 'tuned' for one direction and are inefficient on the other direction. This is not noticeabble in small flexible brush motors. Heavy duty motors are driven by Carbon brushes. These are aligned at an angle and are tuned for optimum speed and torque. Reversing these motors will result in the Carbon brush breaking off.
Some "Aging" of new motors must be done , if you really want to run them in both directions..
It is not advisable to reverse heavy-duty motors (>1A ).

This does not apply (!) to Autorickshaw Wiper motors of Indian origin.

Supario
11-06-2006, 12:58 PM
oh ok, thanks for the help.