Vintage Drill Press Motor Update - need help

[mike93lx]

I have a 1940's Charles Allen Drill Press that I want to swap the motor on. The existing motor has several shorts in the leads coming through the casing and is too old to repair.

It is a 3 phase, 1/2hp, 1725rpm Westinghouse that uses a special mounting bracket that will need to be retained. The motor name plate indicates that it is a 186 frame, but I can't find much on that size online.

I want to switch to single phase, 120V, in the 1/2-1hp range.

I am near clueless on motors, but my thought was to use something like a 56C with a flange adapter, but my Google-fu is not strong on this one.

I can't get the motor off right now, but the bracket looks to have a ~3" square bolt pattern where it attaches to the motor. I think this is too small to find a motor that will bolt right up, but that would be fantastic if one existed.

Any thoughts? If anyone has a surplus motor on hand that would be a good fit, please shoot me a PM. I don't have any good local connections, so I would likely be stuck buying new.

 

[jakemac]

Give this guy on CL a call.
https://boston.craigslist.org/bmw/tls/5955019432.html

I haven't dealt with him, but another member I know of has, and he was happy with the experience.

 

[Davefr]

Any thoughts?

I would try and repair your existing motor since it has such a unique mount. If it's only the lead wires that are damaged you can probably splice on modern THHN wire once you open up the case.

In addition, since it's 3 phase I'd VFD it. Once you convert a DP to VFD you'll never want to go back to changing belts and pulleys.

Even if you can't repair your old motor and have to make a custom mount, then I'd still focus on looking for a good 3 phase, 1 or 1.5 HP 220VAC motor and VFD it.

 

[454ragtop]

With what looks like a very proprietary motor, I think you have 2 options. Best is probably to make a little more effort to fix that one. If it's just failing insulation where the leads enter the junction box, maybe reinsulate with shrink tubing? Other option would be to machine an adapter to go between the current motor mount and a "C" frame motor, which mounts thru the end bell.

Nice drill press by the way, have a very similar Buffalo sliding head drill press, really like it.

 

[mike93lx]

With what looks like a very proprietary motor, I think you have 2 options. Best is probably to make a little more effort to fix that one. If it's just failing insulation where the leads enter the junction box, maybe reinsulate with shrink tubing? Other option would be to machine an adapter to go between the current motor mount and a "C" frame motor, which mounts thru the end bell.

Nice drill press by the way, have a very similar Buffalo sliding head drill press, really like it.

Thanks. I pulled the motor last year and brought it to a local motor shop. The guy wanted to fix it, but didn't want to dig too deep due to its age and couldn't completely fix the shorts. He added some shrink tube, but the space is so tight and the insulation is in such bad shape that I am not confident in the fix. The whole thing that kicked this off was a pretty stout shock that I got from using it.

 

[mike93lx]

Give this guy on CL a call.
https://boston.craigslist.org/bmw/tls/5955019432.html

I haven't dealt with him, but another member I know of has, and he was happy with the experience.

Thanks, I just shot him an email.

 

[mike93lx]

I would try and repair your existing motor since it has such a unique mount. If it's only the lead wires that are damaged you can probably splice on modern THHN wire once you open up the case.

In addition, since it's 3 phase I'd VFD it. Once you convert a DP to VFD you'll never want to go back to changing belts and pulleys.

Even if you can't repair your old motor and have to make a custom mount, then I'd still focus on looking for a good 3 phase, 1 or 1.5 HP 220VAC motor and VFD it.

I explored VFD's for a while, but never bit the bullet. Honestly, this machine is so far past anything that I reasonably need and I've been thinking about parting with it anyway to get something smaller for my tight shop.

 

[454ragtop]

If I didn't already have my Buffalo, I'd trade you for a Craftsman 150 with the third pulley that I have. To me that style of drill is superior to the more common round column drill press. Have you checked with a meter to see if the leads are shorted to the case? Did the guy run it after repairing it?

 

[mike93lx]

If I didn't already have my Buffalo, I'd trade you for a Craftsman 150 with the third pulley that I have. To me that style of drill is superior to the more common round column drill press. Have you checked with a meter to see if the leads are shorted to the case? Did the guy run it after repairing it?

I haven't checked it since the shrink wrap was added.

The leads were shorting to the case and since the frame isn't grounded, it wasn't noticed until I tried drilling a hole in something while barefoot. Quite the zap!

The issue was intermittent, depending on wire placement in the attached box.

 

[Davefr]

The leads were shorting to the case and since the frame isn't grounded, it wasn't noticed until I tried drilling a hole in something while barefoot. Quite the zap!

Most 3 phase motors are really simple. (no centrifical switches, caps, start windings, etc).

I'd remove the two end caps and see if you can spot the source of the short.

 

[mike93lx]

Most 3 phase motors are really simple. (no centrifical switches, caps, start windings, etc).

I'd remove the two end caps and see if you can spot the source of the short.

The short is where the leads exit the case and enter the junction box, no question about it. Problem is access for the repair. The motor is 80 years old. Opening it could cause more damage, but i might be at the point if trying that since i would have to split the case anyway to remove the mounting bracket.

 

[mike93lx]

I thought it would be worth updating this thread.

I finally get the motor fixed. I pulled it completely apart (which ended up being unnecessary since the windings wouldn't separate from the case), removed as much of the old insulation as possible and reinsulated with some quality heat shrink. It's back together and working great.

After pulling it all apart, I found that the bracket simply bolts through to the face of the motor, so replacing it shouldn't be a big deal, assuming I can find something with the same square bolt pattern. But now with it working, I don't realistically think that it will ever need to be replaced.

As an aside, the current Allen Bradley switch (looks like it could be original...~80 years old) seems a little sketchy and I don't like using the rotary phase converter. It won't match the look, but I think it might be time for a VFD.

 

[454ragtop]

Congrats on the motor repair. Those are good switches, probably can be repaired, might need the contacts cleaned up or bent to give a little more tension. But I agree a VFD would be the way to go. Might find one on Ebay for cheap, I just picked up 3 1 HP 115 volt VFDs on there for short money.