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View Full Version : Need help with Grizzly lathe motor



davidwdyer
07-05-2008, 05:14 PM
I need some help with a grizzly lathe. I think it is a model 4,000 and is about two years old. When I switch it on, sometimes it starts up and sometimes it just growls and moves slowly. If I give it a turn with my hand, it does start and run. Sometimes, it starts on its own and sometimes I have to give it a push. Is this a capacitor problem? I confess that I have not taken it apart yet to look, but I have little experience with motors. There must be someone out there who knows a little about this.
Thank you in advance.

David

Quetico Bob
07-05-2008, 05:48 PM
yup, it needs a capacitor.
Cheers, Bob

Boomer
07-05-2008, 11:29 PM
Better get in there and tighten the screws on the terminal block before this happens...
http://bbs.homeshopmachinist.net/showthread.php?t=8333&highlight=grizzly+motor

AEP
07-06-2008, 03:15 AM
I think the contacts are dirty. It happens to my Jet. Motors are made in China. They are junk

airsmith282
07-06-2008, 10:40 AM
a capacitors job is to store current for the most part some capacitors like in motors like this are used not only to start the motor but keep it running if the motor does run it could likey me the armarture that is off or worne bearings/bushings,, i had a problem like this once and it ended up the armature was off it bad bushings where the cause and not the capacitor.. when the caps die on motors they usualy well make them selfs well known so there is no mistaking it at all,you also have to be very carfull if it is the cap thats shot to replace it with the excat same one , when we were trouble shooting mine they gave me a cap the was a bit better so the company said well 10.00 later and a mass explosin and cap fluid all over the place was not pretty let me tell you,,any hwo the company told me to get sutffed yet they were the expert and said it was find to use the better one so i lost 10.00 but we did find out it was not the cap and you have to use the same one that was made for the motor , any how thats the story i got for ya hope it helps...

bighammer
07-06-2008, 12:08 PM
Might not be the capacitor, a lot of offshore motors use a cyntrifugal switch that works off of the blind end of the motor shaft inside a small tin cover on the end bell of the motor housing. The cyntrifugal weight assembly fastens to the end of the motor shaft with a single screw in the center of the shaft, if you srart the motor in reverse rotation often the small screw (a metric equivalent of a #8 or a #l0 machine screw) will back out of the threaded hole in the shaft, because of the spinning weight of the cyntrifigal weight assembly. Remove the screw, put a drop of Lock-tite blue, the removable type, reinstall the screw, and the tin cover, and my motor gave no more trouble.

davidwdyer
07-06-2008, 12:15 PM
Oh Boy! I see that I better take this thing apart quickly and so some investigation.

This is why I really love this forum. Where else could a person get so much good advice and words of experience. Thanks.

I'll try to dismantle the thing tomorrow and let everyone know how it turned out.

davidwdyer
07-09-2008, 08:12 PM
Thanks everybody!

It was one of the two condensers. I couldn't find the exact one here in Brazil, (100 micro farad) but I put two 50's together and it works great.

Rustybolt
07-09-2008, 09:41 PM
It's the start capacitor. Happened to every chinese motor I've ever owned. Just to be on the safe side get a run capacitor too, if it uses one.

Scishopguy
07-10-2008, 01:50 PM
Might not be the capacitor, a lot of offshore motors use a cyntrifugal switch that works off of the blind end of the motor shaft inside a small tin cover on the end bell of the motor housing. The cyntrifugal weight assembly fastens to the end of the motor shaft with a single screw in the center of the shaft, if you srart the motor in reverse rotation often the small screw (a metric equivalent of a #8 or a #l0 machine screw) will back out of the threaded hole in the shaft, because of the spinning weight of the cyntrifigal weight assembly. Remove the screw, put a drop of Lock-tite blue, the removable type, reinstall the screw, and the tin cover, and my motor gave no more trouble.

Good point here. If this motor has a centrifugal switch there are several things that could cause what you describe. I had a Sears table saw with a one horse motor with the switch built in. Some saw dust got sucked into the end of the motor while it was running and then it did what you describe on restart. The fix was to "help it" start and then blow the air hose through it as you turn it off. Keep blowing until it completely stops. Saw dust had gotten between the contacts and kept it from shifting into the low speed windings.