# Grizzly G0752 Speed Control Issue



## 6mmBR (Oct 21, 2015)

Hello all, I've had this lathe since July. I haven't actually used it all that much, so this surprised me. When I turn it on, the speed surges up to 2000 rpm. Moving the speed dial down moves it down, but the speed seems to surge both up and down until finally it settles down. 

I have the belt on the fastest setting, and I will move it to the middle range tomorrow. It seems like maybe the speed control is going whacky, but I'm not sure. 

Does this ring a bell with anybody?


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## 6mmBR (Oct 22, 2015)

I moved the belt to the middle position, and the problem seems to have cleared up. Something weird going on there, I'll keep an eye on it.


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## wrmiller (Oct 22, 2015)

Belt change shouldn't affect anything. Sounds like it could be an intermittent issue in the controller. Have you spoken to anyone at Grizzly about it yet?


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## 6mmBR (Oct 22, 2015)

No not yet. I thought with all of the people here somebody may have run across something similar. I will check with Grizzly tomorrow. 
Intermittent problems can be a bear to solve, no pun intended. 

Thanks for your belt info. I was just reaching.


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## Ulma Doctor (Oct 24, 2015)

i'm not an expert on the grizzly equipment, but it sounds to me like there is a fault in the speed control board or possibly a potentiometer is failing or not trimmed correctly


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## 6mmBR (Oct 24, 2015)

I emailed Grizzly tech support Thursday. I'll see what they have to say when they get back to me. In the meantime, I moved the belt as I said above, and it's working fine. I made up a small tool out of aluminum, and had no issues. 

Hopefully, they'll have had this issue before and can handle it for me before it gets worse.


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## wrmiller (Oct 24, 2015)

Don't take this the wrong way, but did you pop the cover and check for loose connections? It was part of my checkout when I got my PM25 and actually found a few loose screws (not counting the ones in my head, those are permanent...). Just a suggestion if you haven't already done this.


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## 6mmBR (Oct 25, 2015)

No problem. I did a quick once over, but maybe it's worth looking harder. It can't hurt, right?


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## 6mmBR (Nov 1, 2015)

In case anybody else has this problem; Grizzly directed me to test the potentiometer / speed control.  They had me take the wires to the VFD loose and test it from there. The pot tested out as good. The tech support guy thought it just might have been some debris in the pot, or perhaps some sort of glitch in the VFD. 

They had no range of serial numbers with any issues like I had, so it wasn't likely to be a common thing. 

I checked all the connections in the back while I was there, and all looked good and tight. I'll keep an eye on it, and give Grizzly a call / email  if it re-occurs. So far, it hasn't.


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## 6mmBR (Dec 6, 2015)

This has been interesting.  The problem re-occurred, and after several emails with Grizzly, they sent me to Delta tech support. That's who makes the VFD. Finally, it was decided to send me a new VFD which I replaced yesterday. 

All seems well now. I thought I'd post this resolution in case it happens to any other G0752 owners on the board.  It could save somebody some grief. Grizzly stood behind their stuff, no problems at all. They are pretty busy though, so it takes several days between sending and receiving an email response.  But they worked with me until the problem was fixed.


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