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Drill press motor short to case

picah

Active member
Joined
Aug 2, 2009
Messages
41
Guys
Need some help
Have a 60 year old craftsman drill press with motor of same vintage. Turned it on today and sparks from motor. Took it apart. Stator and armature good. Problem was the wires that go from stator to terminal board had cracked 60 year old insulation. Wires shorted to case. Very obvious cause of sparks. Can I and how can I replace those short lengths of wires. Can’t see where they end on the stator and stator is fixed inside the motor casing
Also I see 4 wires coming from the stator but only three appeared to actually go to the terminal board. Is the seemingly unconnected black 4th wire not used? Switch wire? Motor has a remote switch at the end of a two foot long length of wiring that exits the motor body where the power cord exits
I was thinking I could slide a double layer of shrink wrap tubing all the way down the 3 wires to where they must be soldered to the stator, shrink them and then just reattach. Yes. No. Dangerous?
If I need to take it to a repair shop how much would it be to fix. Again stator and armature both good. Dirty but no signs of any burning at all
Many thx
 
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picah

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Aug 2, 2009
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Any idea of cost for this repair? It’s all time and not any parts I can see need to be replaced
Thx
 

American Locomotive

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You can try a motor repair shop, but it's really not economical to rebuild electric motors under 15HP or so. Even then it's kinda iffy. At most they'd likely be willing to change the bearings.

Your best bet is to try the heatshrink idea, or just replace the motor.
 

matt_i

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SE Michigan
I think your heat shrink idea is excellent. Even if you didn't shrink the tube at all you'd still be ahead.

If that doesn't work I'd metal scrap it. As American Locomotive states, repairing a small motor would be :yikes: expensive.
 
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picah

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Aug 2, 2009
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Thanks for the feedback. Any idea as to the 4th wire in there?
Much obliged
Stay safe
 
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picah

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Aug 2, 2009
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41
Good point but end of fourth wire looks clean and not burnt
Are these old drill press motors 3 phase?
 
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picah

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Aug 2, 2009
Messages
41
Just got a better look
The 3 wires are red, yellow, and blue/green and run to the stator.
The red wire was the broken one but I now see where it connects to the terminal board as the other end is still connected
The black wire is to the capacitor
So I see where all the wires terminate on both ends. That’s good
Now it’s a matter of whether the shrink wrap idea is feasible

How tough is it to remove the stator from the case if it needs to be done? How do I do it?

Finally, if I need to buy a new motor what is your suggestion and where do I source it?

Many thx
Need this back in operation ASAP
 

PugetDude

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Mar 13, 2013
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22,446
Location
Superstition Mountains, AZ
Try the heatshrink first, it costs you nothing.
If you need a new motor, look online to match your frame size (56, 48, etc.) and RPM
Grizzly sells replacement drill press motors, but they're available from many other suppliers.
In May I bought a made in USA Leeson 1 hp 56 Frame Single phase 3450 RPM motor on eBay for $129.00 w/ free shipping.
 

Robbie B

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Jun 24, 2014
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Sunny side of hell
If it didn’t burn the windings out a motor shop could bake the insulation off dip it and re bake it. We just had a 250hp motor done that way at work. Got lucky and managed to catch it cogging before if burned up. Reinsulated and new bearing and it’s doing great now.
 
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