Motor spin, reversable via starter cap?

[Mitchell Andrus]

Can the direction of a motor be changed by rewiring the starter cap? Assuming the 'nudge' delivered is all it takes.....

I'd love to reverse the travel on my 6"x89" horizontal belt sander.
.

[Dan Friedrichs]

Generally, yes. If you flip either the connections of the "run" winding or the "start" winding (but not both), you should be able to get it to spin the opposite direction.

[Mitchell Andrus]

I am concerned that the motor would then be 'pushing' the paper across the platen as the motor is now on the right, pulling left to right - towards the motor and pulling away from resistance.

If I reverse this, the motor would be pushing the paper away, from right to left - away from the motor and pushing towards resistance. Maybe the paper would bunch up just slightly and slip on the drum. -??-

The paper is plenty tight on the carriage, but.... be interesting to find out if it works this way before risking the windings on a $400.00 motor.
.

[Dave Beauchesne]

Generally, yes. If you flip either the connections of the "run" winding or the "start" winding (but not both), you should be able to get it to spin the opposite direction.

Dan:

With all due respect, on what do you base your suggestion??

I have been a HVAC technician for 31 years, and NEVER have I seen / heard what you are suggesting.

Some motors are reversible, but it is a change in the winding configuration, not merely a swapping the leads on a capacitor as suggested. Now, that being said, I am open to something new, but if the wiring diagram on the motor doesn't say to do it XXXXXX way, you are jeopardizing the motor.

JMHO

Dave Beauchesne

[Dan Friedrichs]

Dave,

I agree that not all induction motors can be reversed. Also, I didn't say to flip the capacitor leads, but to flip the windings (the same as you said).

[Dave Beauchesne]

Dave,

I agree that not all induction motors can be reversed. Also, I didn't say to flip the capacitor leads, but to flip the windings (the same as you said).

Dan:

I stand corrected. It was late and I read into your response the 'capacitor' notion.

Flipping the run and / or start windings is only something that should be done if the motor configuration ( and associated wiring diagram ) allow it.

My apologies - - -

Respectfully;

Dave Beauchesne

[Chip Lindley]

Mitchell, I don't think your sander cares which direction the paper travels. But, the belt, of course, needs to travel toward the DC hood to afford any sort of dust collection. If running reverse, dust will be thrown right back at you.

As for motor rotation, some motors have no interchangable leads to allow reversing rotation. Special duty motors used on compressors or tablesaws come to mind. Your sander motor is probably one of these; intended for one direction of rotation; a couple of dollars cheaper to produce this way! I will contend that, unless there is a schematic on the motor plate for changing leads for opposite rotation, your motor will run only one direction. (without major surgery at a motor shop!)