Hi Folks, been a while, good to be back to Knots.
I have a GE motor I need to reverse for my Lathe. The motor is probably 30 years or older. (this is a motor mounting problem not so I can run my lathe in reverse)
I’ve tried a number of wire swaps but can’t seem to get it to start in the opposite direction (currently set up for clockwise rotation)
Here is a picture of the “circut board” upside down
Red wire on left comes from start capacitor and eventually connects to blue/green wire on right. The circut from the start capacitor to the blue/green wire is only closed during motor start. After the motor gets to speed, the start circut opens up Copper “Y” is part of the startup mechanism.
AC power is applied at lug 2 and lug 4. Lug 1 and 3 are unused.
The black wire on lug 3 connects to the bottom of the “Y” the red wire on lug 1 connects to the one arm of the “Y”.
The purple wire runs from the “reset” switch to lug 4.
Yellow wire runs from “reset” to the run-winding.
The hole in the side of the casing suggests that reversing the motor should be easy. The instructions on the back of the cover plate do not tell how to reverse the motor. and the rating plate, amazingly, had a sticker on it that said “Clockwise” I’m assuming that that sticker was put on the motor years ago to indicate how the motor was originally set up.
I have done an extensive web search on how to reverse this moter – any ideas?
Worst case, I can disable the start circuit and manually start the motor in counterclockwise direction but that strikes me as dangerous in a number of ways…
Thanks,
Mark
Mark it with Chalk,
Cut it with an Ax.
Replies
Not all motors are reversible, and every motor I've seen that can be reversed has a removable connection box cover on the outside of the motor that allows easy access to the wiring to reverse the rotation, with no need to remove the motor's end housing.
The fact that your motor doesn't have a connection box, that it lists the direction of rotation right on the plate, and that it doesn't have a diagram right on the plate or inside of the box cover with directions for reversing the rotation would all suggest that your motor can't be reversed.
John White, Shop Manager, Fine Woodworking Magazine
bummer. Thanks. I guess I'll have to turn my shop upside down :-)Measure it with a Micrometer,
Mark it with Chalk,
Cut it with an Ax.
Visit my woodworking blog Dust Maker
It would take some hard convincing to have me believe it cannot be reversed-but then I have had little experience with American motors. In theory it is the field winding leads from within that need to be interposed.
Anyway, worst case scenario in my books would be to change the motor round on its base-you may be lucky and have the space?
JohnWW is correct not all motors are reversable, Your attachment is the wiring for the Start/Run winding centrifugal throw out switch. Sorry.
Work Safe, Count to 10 when your done for the day !!
Bruce S.
Now the interesting thing is if I disconnect the starter circuit I can start the motor manually in either direction - as you would expect from a inductance motor...M.Measure it with a Micrometer,
Mark it with Chalk,
Cut it with an Ax.
Visit my woodworking blog Dust Maker
mark, the safest thing for you to do is take your motor to a motor repair shop, I worked in one for many years so I would bet that from what I see your motor could be reversed by changing two wires and they should do it fairly reasonably. I am not trying to be smart, but I would not want to risk your life or shop based on a picture on the net. When you disconnect the cap. you disable the start circuit which is why you are able to rotate the motor in the desired direction, that circuit is what gives the motor a brief burst of power to start the motor, at the cost of too many amps for the motor to run without going up in smoke. Mark I hope this helps that was my intent.
marvin
Is your lathe belt driven there may be another way
You can make it fool proof but not idiot proof
It's hard to tell from the pic, but it looks like there are only three leads into the stator area (red, yellow, green), suggesting it's single-voltage and non-reversible. To reverse rotation you'd have to switch the two ends of the start winding, but only one end is available (going through the centrifugal switch - green, maybe?). The other end appears to be permanently connected to the run winding, somewhere inside the stator winding area.
I might suggest sniffing around your local friendly junkyard or scrapyard, as some of them keep a pile of motors around for resale (often by weight). HVAC contractors also scrap air handlers on a regular basis - ask yours if you can pull a motor from a belt-driven blower in the pile. It helps if they're servicing your A/C when you ask. So does a sawbuck or two, though I've gotten lots of them for free.
Be seeing you...
Mark do you have a lefty's lathe? Most lathes turn clockwise, the motor is on the left end of the lathe when looking straight at it.If the rotation was counter clockwise you would spin a face plate or chuck right off the spindle.
I built my own lathe, being left handed and at times not real bright, I put the motor on the right side of the lathe. Worked great for turning between centers, I was real proud of myself for buildind a quality tool.
One day I decided I would mount the face plate, I wasn't going to turn anything just piddling around.This was the first time I had mounted a face plate.I turned the lathe on, watched the face plate spin off,hit the floor,kept on rolling until it went out the door and hit my fence about 60 feet away. I recovered the face plate, then installed the motor on the left side of the lathe as I should have from the get go.
That being said, I imagine you may know you can reverse the rotation of the lathe without touching the motor. You would have to put a twist in the belt, this will change the rotation. If the motor does not have a belt drive you will need another motor.
mike
30 years old is pretty old. If the windings are in good shape a motor shop could tap into it and get reverse. Might cost as much as replacing the motor in the long run.
Have you considered a replacing the motor with a three phase motor and a Variable Frequency Drive? VFD's for one horse motors are available to run on 120 volts and will give you infinitely variable speed, soft start and lots of other bells and whistles. Most modern lathes are using VFD technology. We have it on the feed for our 12" Wadkin moulder.
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