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Motor won't run

Posted: Tue Jun 05, 2012 1:28 pm
by mountain4don
I received a ShopSmith V from a family member that died a year or so ago. Occasionally the motor wouldn't run after switching it on. I didn't hear any humming from the motor or any sound from it. Naturally I checked the circuit breaker and power at the receptacle and it is good. I opened the port on the back of the power head and had 110 volts on the in side of the switch, but something less on the out side to the motor. So I replaced the switch. But that didn't help. The motor still doesn't start or make any noise. It has been sitting not running for a few months. And before that I had used it only occasionally to run a band saw. Can anybody give me some suggestions on how to check it out? Or proceedures to check the system? I was just setting up to cut a bunch of custom moldings and baseboard for our house.

Posted: Tue Jun 05, 2012 3:01 pm
by wa2crk
Don
If I read correctly the line voltage on the load side of the switch is lower than the supply side. Is that correct? If so how much? I would check the power cord for abrasions in the insulation where water could have seeped in. It appears that there is a resistance between the plug and the load side of the switch.
When the switch is thrown and the motor draws current the resistance may be dropping the voltage.
Check the resistance of all of the associated wiring and try again. If the motor windings were bad there should be no voltage drop across the switch.
Did you wire the switch correctly? I get the sense that you know a few things about wiring and electricity. Correct?
In any case check back for more info, I know that it will appear here.
Bill V

Further developments

Posted: Tue Jun 05, 2012 4:28 pm
by mountain4don
I replaced the switch with a double pole single throw similar to the original switch, and still got some funny readings on voltages between the poles on the switch. 127 volts across the power cord coming in, but 60 or so volts across the motor wires and diagonally from the hot in to the white motor wire. So I unplugged it and took the switch out the inspection cover on the back so I could get better voltage readings on the switch terminals. And plugged it back in and got 127 volts across the line terminals. When I flipped the switch on to check the voltage on the motor terminals again, the motor started up! And it starts up consistantly when turned on and off! This is a strange deal that I can't figure out. Anybody have any ideas why the motor is non-functional when the switch is mounted in the head stock? And what else I can try to find the problem?

Posted: Tue Jun 05, 2012 4:55 pm
by beeg
Could ya have a broken/loose wire on the motor wires?

Motor working again!

Posted: Tue Jun 05, 2012 6:07 pm
by mountain4don
I resolved the problem! I thank you all for your help and the help from reviewing other listings on this forum. After getting all the strange voltage readings across the wires on back of the switch, and the motor running sometimes and not other times, I looked at one of the other suggestions and turned it on and moved all the wires from the motor all the way back to the plug at the receptacle. And low-and-behold, the motor started and stopped when I wiggled the wire close to the plug. So I immediatly cut off the plug and about 6" of wire next to it and put a new plug on. And it works! I got it all cleaned out and running again with a new 2-bearing quill and now I am ready to finish building my wife's dream house. Getting ready to dato cut all the 1905 era trim for the windows and baseboards on the first floor of our old farm house. Can a vintage ShopSmith do it? I cut down some oak trees on our farm and took them to a local saw mill and had them cut it and plane it on 3 sides into random width 3/4" planks. Some of them came out 24" wide (they were some big trees). And they look beautiful after drying in the barn for a year. :D

Posted: Tue Jun 05, 2012 8:10 pm
by JPG
Now that the motor runs reliably, do a complete lubrication so it will be mechanically sound prior to engaging that oak!:)

Then lube often!

Cleaned it up

Posted: Wed Jun 06, 2012 2:57 pm
by mountain4don
I did just that. I took off the headstock cover and blew it out real good with the air compressor, and lubed the speed changer shafts with sewing machine oil, and the threaded clamp shaft with graphite and checked the belt tension and some other things as I went through the recommendations in the book. So now I am ready to cut some wood again. And my father's old ShopSmith lives on again! :D

Posted: Wed Jun 06, 2012 3:39 pm
by dusty
mountain4don wrote:I did just that. I took off the headstock cover and blew it out real good with the air compressor, and lubed the speed changer shafts with sewing machine oil, and the threaded clamp shaft with graphite and checked the belt tension and some other things as I went through the recommendations in the book. So now I am ready to cut some wood again. And my father's old ShopSmith lives on again! :D
I would suggest that you give serious consideration to putting in new bearings.

bearings?

Posted: Wed Jun 06, 2012 6:21 pm
by mountain4don
Which bearings do you suggest I replace? I don't know much about these machines. Or how much trouble it is to replace stuff. :confused:

Posted: Wed Jun 06, 2012 6:34 pm
by dusty
mountain4don wrote:Which bearings do you suggest I replace? I don't know much about these machines. Or how much trouble it is to replace stuff. :confused:
I was thinking of the motor bearings. The others need not be changed unless they become a problem. Bad bearings in the motor can lead to greater problems with the motor. Just my idea of "preventative maintenance".

If you don't feel comfortable changing motor bearings, use a motor shop.

Do not fear any of the Mark V repairs. This entire machine is truly user friendly.