[OP]
Contributor
Today I was finishing up a walnut bowl and noticed the low end speed of the G0766 is whacked. From dead stop to about 80 rpm on low speed belt config, it's OK, but a hair above 80 rpm, and it shoot to 800 rpm. No in between. What should I do? I blew out the belt compartment and also to outside of VFR, but no change. HELP please.
Maker of Fine Kindling, and small metal chips on the floor.
Embellishments to the Stars - or wannabees.
Member
Call Grizzly, they would be your best bet for good information.
Fred
Contributor
Have you tried disconnecting power, letting it set unpowered for a couple minutes and then reconnecting power? Some motor controllers need to have power removed to reset if they experience an error.
Ken
So much to learn, so little time.....
Contributor
Sounds like the speed potentiometer failed on you. It is a small, inexpensive part, and they will replace it. If I were you, I would try to unplug the lathe for a few minutes, then hit all the reset buttons, and see if that brought it all back up....if not the pot likely needs to be replaced. Any looseness in the knob turning, or can you feel the resistance in the pot?Originally Posted by Mark Greenbaum
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Member
Yep, sounds like the speed pot, it's about a three dollar part but Grizzly will replace it for free. Mine [G0733] started acting up about a month ago. I contacted Grizzly and they promptly sent a new potentiometer no questions asked.
Member
Sounds like the same problem I had. It was the potentiometer. I got one from Grizzly,but it took them a long time to get it to me,so I ordered three of them from Amazon for $15 for all three. No problem since then.
Contributor
If it is a pot I would suggest getting a honeywell rv4n type (milatary grade) http://www.newark.com/webapp/wcs/sto...&storeId=10194
PS. If you are not sure, here is a simple way to test http://www.wikihow.com/Test-a-Potentiometer (if you don't have a multimeter, the cheapest one from harbor freight would do the job)
Last edited by Michael Schneider; 03-19-2016 at 8:12 PM.
Contributor
I concur. Don't mess with the cheesy pots. This is a component that sees very heavy use and a heavy duty part should be used.
Bill
Contributor
I took your advice and bought a better one along time ago just to have it on hand. I think Newark was the source.
[OP]
Contributor
Here's a couple of picture of the 2nd failed potentiometer. The coil ahs frayed near the middle causing dead shorts. I sure hope the 3rd will behave, but I have the Honeywell in my back pocket as a spare in case.
1107171100.jpg1107171057a.jpg1107171057.jpg
Maker of Fine Kindling, and small metal chips on the floor.
Embellishments to the Stars - or wannabees.
Contributor
I can't believe that they use wirewound pots which are more appropriately intended for applications where the pot setting is rarely adjusted. As mentioned previously, conductive plastic pots are the only solution that makes sense.
Bill
[OP]
Contributor
What would a good replacement, that is made in USA, and can handle 1000's of rotations be? I've got the Honeywell as a spare, but is that going to be sufficient? What do Powermatics use? I cannot find a good alternate part number for theirs, and $75 for a control pot seems a bit much $$$.
Maker of Fine Kindling, and small metal chips on the floor.
Embellishments to the Stars - or wannabees.
Contributor
If the Honeywell pot has the right form factor (¼" shaft diameter with threaded mounting bushing that fits the hole size), linear taper, and correct resistance then you should be good to go. Conductive plastic pots have excellent specs WRT wear cycles. It's not necessary to go to MIL-SPEC pots unless you're turning in extreme environments (South Pole, steaming jungle with fungus growing on everything, salt water spray, top of Mount Everest, bottom of Mariana Trench in the Pacific Ocean, Sahara desert sandstorm and 130°, Mississippi delta mud, direct nuclear hit, run over by a tank, etc).
BTW, the pot referenced in post #7 isn't MIL-SPEC, it's commercial grade, but it's perfect for what you want.
Last edited by Bill Boehme; 11-08-2017 at 9:03 PM. Reason: More information
Bill
[OP]
Contributor
What I ordered that took the long way around from SA to CA to USA was this:
Maker of Fine Kindling, and small metal chips on the floor.
Embellishments to the Stars - or wannabees.
[OP]
Contributor
Just got home from a party for my kids, and the unit was unplugged all day. I plugged it into power, and it's the same as it was before - 0-80 rpm, fine; 81 jumps to 800 rpms, nothing in between. I don't know what you mean by reset buttons, so please let me know what those are. I always turn power on in neutral rotation. The knob was tight on the pot shaft. I checked that earlier.
Last edited by Mark Greenbaum; 03-19-2016 at 11:44 PM.
Maker of Fine Kindling, and small metal chips on the floor.
Embellishments to the Stars - or wannabees.
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