South Bend lathe only turns one way

[cmccuist1]

This is more of a motor question than a lathe question. My South Bend 10" lathe has a 1 hp, 110V motor. When I put the drum switch in reverse, it runs fine. When I put it in forward, it just hums. If it was the start up contact, then wouldn't it hum on both forward and reverse?

Any idea why it does that?

 

[GeoBruin]

Retracted for apparently bad information.

 

[Whitworth]

Drum switch wired incorrectly.

 

[cmccuist1]

There was a youtube video that showed a drum switch and 110v motor - single phase. I think the motor has to have 6 wires. That's probably it. Wired incorrectly.

Thanks!

 

[larry_g]

Can you show the wiring data plate from the motor? If it shows that reversing wire 5 & 8 to reverse the motor then you can reverse it with a drum switch. Also look at the wiring hook-up for the drum switch. If your lucky then there is a diagram inside the switch cover. It can be done if you have the right parts.

lg
no neat sig line

 

[cmccuist1]

I will look for those diagrams when I go to the shop tomorrow. Thanks!

In the reverse, the machine is very smooth and quiet, so I think the motor is in good working condition.

 

[cmccuist1]

This is a lathe I just picked up off of FBMP. Here's some pics of the offload.

Needs a paint job, but the ways are in good shape and it turns real smooth.

 

[micromind]

If it worked at one time and no wiring has been changed, it's not a connection problem, it's most likely because a contact on the drum switch has failed or gotten oily enough to look like it has failed.

 

[darkzero]

EDIT: N/M, that lathe/motor was wired for 220v I believe. I don't remember the video much, haven't rewatched it.

Mr. Pete had a video not too long ago about rewiring the drum switch on his Craftsman Atlas lathe. No idea if his issue will apply to you.

Well it seems like not that long ago to me but it was well over a year ago. Haha

 

[larry_g]

Drum Reversing Switch Wiring Diagrams | eMotors Direct

www.emotorsdirect.ca

Above is some good information.

Do you know if this setup ever worked correctly? Was the 120v motor recently swapped in?

lg
no neat sig line

 

[Whitworth]

Looking at that rats' nest of armored cable, I'd be surprised if it didn't have electrical problems.

Otherwise, it's a really nice looking lathe !

 

[cmccuist1]

The motor is a swap. Unfortunately, wiring looks original! So I got into the drum switch and wire brushed the sketchy parts. Now it’s working great!

The rats nest on the back needs to be cleaned up. I have GCFI on the outlet and a 20 amp breaker so I probably don’t need the reset switch that’s currently on there.

Thanks for all the replies!!

 

[Toold_up]

Do you have one of those gray and red Dayton drum switches?

If so, throw it away and buy something better. I had two fail on me and wound up replacing them with Square-D switches I bought on ebay.