View Full Version : need advice on reversing my motor
truetone
04-08-2007, 05:00 AM
I have a high speed sewing machine motor and foot switch and the motor has two wires, hot and neutral. Is there a way I can hook up a switch to make it go in reverse? And how are the foot switches wired in parallel?
David King
04-08-2007, 05:30 AM
I have a high speed sewing machine motor and foot switch and the motor has two wires, hot and neutral. Is there a way I can hook up a switch to make it go in reverse?
This is relatively easy, take the two nuts off the back of the motor and crack it open, you should see the two wires going to the brushes. All you need to do is switch the wires going to the brushes with a DPDT switch, choose a switch that can handle 2-3 Amps at 115V. Cut the wires going to the motor brushes. That gives you 4 ends. Your switch has 6 lugs, ignore the two in the middle, connect a short jumper wire diagonally between the opposite corners, connect a second jumper that goes diagonally between the remaining corner lugs. The jumpers now form a tall "X". Attach the two wires from the brushes to the top of that "X". Attach the two wires from the pedal and wall plug to the bottom of that "X". You are done unless you forgot to put heat shrink tubing over all the switch lugs...
truetone
04-08-2007, 05:58 AM
quick qestion, what will I do with the original wires sticking out of the motor.
here are some pics of the motor, which ones do I cut?
Front
http://i24.photobucket.com/albums/c25/Cole_01/Picture062.jpg
http://i24.photobucket.com/albums/c25/Cole_01/Picture060.jpg
Back
http://i24.photobucket.com/albums/c25/Cole_01/Picture063.jpg
Joe Gwinn
04-08-2007, 06:59 PM
quick qestion, what will I do with the original wires sticking out of the motor.
here are some pics of the motor, which ones do I cut?
Front
http://i24.photobucket.com/albums/c25/Cole_01/Picture062.jpg
http://i24.photobucket.com/albums/c25/Cole_01/Picture060.jpg
Back
http://i24.photobucket.com/albums/c25/Cole_01/Picture063.jpg
As for the blurry photos, it often helps to put the camera in Macro mode (often symbolized with a pictogram of a tulip flower).
This appears to be a series-wound universal (AC and DC) motor, which is just what you would expect in a sewing machine. By "series-wound", what is meant is that the rotor (accessed via the commutator and two brushes) is in series with the field coil (the windings on the laminated steel frame). To reverse the direction of rotation, one must cut the two wires going to the commutator brushes and install the reversing switch so that one can flip the rotor connections end for end.
ANote that the field coil may be two half coils, with the commutator (and thus rotor) in the middle. Reversing the brush connections will always work, though.
Be aware that the motor may not like being run in reverse, as it was not designed to be reversed, even though reversal is possible electrically.
truetone
04-08-2007, 07:27 PM
really sorry for the bad photos, I never looked at the pics before I posted them. I did some in the macro and it worked great.
are these the wires I cut?
http://i24.photobucket.com/albums/c25/Cole_01/Picture071.jpg
heres some more pics
http://i24.photobucket.com/albums/c25/Cole_01/Picture067.jpg
http://i24.photobucket.com/albums/c25/Cole_01/Picture065.jpg
thank you guys for all your help I greatly appreciate it!
Joe is right...
Reversing the brushes (the old Lionel train motor reversing method) will work, but the motor will be a little noisier, spark more than usual, and overheat if the fan blades in the motor are prebent to maximize airflow through the motor in its 'usual' direction. IMHO it's better to buy a DC motor for reversing applications.
Ken
Llanonite
04-09-2007, 04:48 AM
This appears to be a series-wound universal (AC and DC) motor, which is just what you would expect in a sewing machine. By "series-wound", what is meant is that the rotor (accessed via the commutator and two brushes) is in series with the field coil (the windings on the laminated steel frame). To reverse the direction of rotation, one must cut the two wires going to the commutator brushes and install the reversing switch so that one can flip the rotor connections end for end.
That's exactly the tip I was looking for. :D
Now I can move on with the rest of the project.
truetone
04-09-2007, 06:59 AM
so how did you wire it up Llanonite
Llanonite
04-09-2007, 04:43 PM
I realized after finishing that I should have taken pictures. Sorry.
So I sketched a drawing. This drawing is the way I made mine.
The switch is the one I had available, I'm sure yours may be different.
But you should be able to get an idea of what to do.
The one drawback was having to add four more wires to come
through the motor housing wire hole. It was a snug fit.
I hope this helps.
:D
truetone
04-11-2007, 04:09 AM
I dont know guys, I tried cutting the wires to the brushes and hooking everything up to a dpdt swith...I'm just not having any luck. when I look at the motor the wires coming from the coil dont go directly to the brushes one does and the other doesn't? what could I be doing wrong
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