Quick Grizzly G0766 noise question

[David Bolson]

After my delivery misadventures, I'm finally turning again. After 3 months of not turning my skills have definitely deteriorated.

Anyway, the Grizzly seems much louder to me than my last lathe, a Nova 2024. I'm just wondering if this is standard and acceptable, or whether there's an issue. I went to the trouble of making a video, but now can't figure out how to post it without jumping through hoops. Anyway, I used a decibel meter app on my android and placed it on the bed near the spindle. At the higher speeds, it briefly hit 77db and was steady at about 74-75db.

If that's normal, I'm sure I'll get used to it. Just checking...

David

[Dwight Rutherford]

There is a Grizzley Group here that may be able to answer your question. Go to “community “ then chose “groups”.

[David Walser]

David -- I cannot say if 74-75db is 'loud' for a Grizzly G0766. I will say that a Nova DVR lathe is quieter than most other lathes. That's one of its advantages, although most people don't feel competing lathes are loud enough to be bothersome. The reason the DVR is quieter is because it is direct drive. Assuming the spindle bearings are in good shape, the only sound you'll hear is the motor spinning. With other designs, you have the motor spinning, plus the sound from the pulleys and belts. Even if everything is perfectly aligned, the spinning pulleys and belts make some sound. Not a lot, but more than you'll get from the DVR.

However, 75db is the sound output of a typical dishwasher. Not very loud at all.

[tom lucas]

I've never measured sound, but it's not loud. It does get louder with higher rpms. But at lower RPMs the inverter puts out a high pitched sound that might seem annoying to younger ears. I've never felt is was signs of an issue. Of course it's noisier with a piece of wood on it as opposed to spinning with no load.

[David Bolson]

Maybe I was spoiled a bit by the relative quietness of the Nova. When I started turning on the Grizzly I was a bit alarmed by the sound, wondering if something was off. I can live with it, just wanted to make sure that it was normal.

[John Hart]

Odd.....my grizzley doesn't make any noise at all. I was astounded by how quiet it is

[Brice Rogers]

David Bolson, another person posted on GGMG (Grizzly lathe forum) but in regards to a clicking noise. It sound like yours is a continuous whine?

I'd loosen the belt to the spindle to the point that you can remove it. Then take your hand and slowly rotate the spindle. It should be silky smooth. Do the same for the motor. Then try to wiggle both ends of the spindle and the motor shaft. There shouldn't be any play. I'd also turn on the motor w/o the belt on. If the motor spindle is smooth but the whine is coming from the motor, perhaps this is normal.

There are some parameters on the 3 phase converter that you could play with that could affect the motor and converter noise. There are some people who have posted on the GGMG how to do this.

[David Bolson]

David Bolson, another person posted on GGMG (Grizzly lathe forum) but in regards to a clicking noise. It sound like yours is a continuous whine?

I'd loosen the belt to the spindle to the point that you can remove it. Then take your hand and slowly rotate the spindle. It should be silky smooth. Do the same for the motor. Then try to wiggle both ends of the spindle and the motor shaft. There shouldn't be any play. I'd also turn on the motor w/o the belt on. If the motor spindle is smooth but the whine is coming from the motor, perhaps this is normal.

There are some parameters on the 3 phase converter that you could play with that could affect the motor and converter noise. There are some people who have posted on the GGMG how to do this.

Brice - The spindle is smooth. The motor noise is the same without the belt engaged.

There seems to be something wrong with the Grizzly Group search feature. I first searched for "noise" and came up with "no results". Even though the very first thread in the group is titled, "Spindle noise". I then searched the word "motor" and got "no results" again. Which is impossible.

I decided to call Grizzly to find out if the had a spec for motor noise level. They do not. The tech I talked to said that he works on a G0766 and that it's "quiet". His only suggestion was to take off the fan cover and check the fan, which I'll do. So far, I haven't gotten anyone who says their lathe is "quiet" to do a decibel reading, so I'll never be sure my lathe is normal, but it works, so I'll work with it.

[John Hart]

I don't have a decibel meter, but I can say this, my shop lights have a slight hum which I can barely hear and they are louder than my 766

[Richard Coers]

You might try putting the video on youtube and sharing the link here. If the spindle is smooth, take the belt completely off the motor and run it through a range. If the motor is out of balance, that can cause quite a bit of noise. Here is an interesting 0766 repair video, which references a new Laguna lathe video for her next video. I see she never heard of brinelling a bearing! https://www.youtube.com/watch?v=1_JEW_pQGYc

[Brice Rogers]

David Bolson, if you were in an area with a wood turning club, perhaps you could find another G0766 owner and you could do a comparison. Also, I think that I recall that Griz could give you contact info on other G0766 owners in your area. Or you could post your location here and perhaps another member will read and contact you. I live 20 miles north of San Diego, if that helps.

[David Bolson]

David Bolson, if you were in an area with a wood turning club, perhaps you could find another G0766 owner and you could do a comparison. Also, I think that I recall that Griz could give you contact info on other G0766 owners in your area. Or you could post your location here and perhaps another member will read and contact you. I live 20 miles north of San Diego, if that helps.

Good idea. I didn’t even realize that I don’t have my location listed. I’m in North Jersey. I do belong to a club here, although we haven’t physically met for a long time. I’ll ask there also.

[Barry McFadden]

You might try putting the video on youtube and sharing the link here. If the spindle is smooth, take the belt completely off the motor and run it through a range. If the motor is out of balance, that can cause quite a bit of noise. Here is an interesting 0766 repair video, which references a new Laguna lathe video for her next video. I see she never heard of brinelling a bearing! https://www.youtube.com/watch?v=1_JEW_pQGYc

I just watched a few of her videos and it seems she has a problem with everything she buys!!

[David Bolson]

Alright, I’m backing up a step. I now think I was a bit of an alarmist on this. This is what I realized last night: I’m not used to dealing with belts. Never had to change a belt with my Nova. When I first started using the Grizzly, I was sanding a project that I had never finished on my Nova. I used a slow speed on Belt “B”. Then I went into regular turning never having changed the belt, while moving on to high speeds. I forgot to change the belt!

What I figured out last night is this:
If I only use belt “B” up to 700 RPM’s, the DB measurement is at 60 or less, which is quite comfortable.
If I switch to belt “A” after that, I don’t get over 60 DB until 2000 RPM.
So while the lathe is, in my opinion, loud at the highest RPM’s, I’ll rarely get there.
I also might figure out a faster way to change belts. Unscrewing the latch is a bit slow. Probably something with a magnet.

Other things I learned:
There is a blip at 400 RPM on belt “B” and 1100 RPM on belt “A”, where it gets significantly louder, but then the sound decreases again as the RPM increases. I’ll just learn over time to avoid those speeds.

There is a “chirping” sound that gets louder and louder starting about 1800 RPM coming from the handwheel area. It’s not the handwheel itself, as I took it off and the chirping didn’t change.

The motor itself is not what makes the bulk of the noise. Most of the noise comes from the large black box behind the headstock.

Also, I figured this out:
Depending on what I’m doing, I sometimes wear gloves. I was working on a large bowl with my gloves and every time I stopped the lathe by moving the top knob from “F” to “O” and then turned it back on again, the speed would increase dramatically. I thought that I already had a bad potentiometer. I finally realized that when I was turning the lathe off, the tip of my glove was nudging the speed knob. Problem solved, but I do wish those knobs were a little farther apart.

Thanks for the help!

David

[John K Jordan]

I've never used that lathe but have used a bunch of others. The sound you describe still doesn't seem right to me.

The lathe should be usable up to its full speed without clicks, chirping, or speeds that need to be avoided. In general, a sound at a specific speed may indicate a resonance at that frequency due to a mechanical imbalance. Could be in the spindle, the motor, or a vibration due to belt tightness. Some people tighten a belt too much on a lathe like a Jet or PM by pushing down the lever too hard - someone who experienced early bearing failure said Jet tech support told them the weight of the motor is enough to properly tension the belt. If there is room inside the headstock you can slip the belt off the pulleys and run just the motor through the speed range to check it. With the belt off, the spindle should turn freely by hand - spin it and it should continue to spin for a moment. With the belt off you may be able to rig up something to mechanically drive the spindle to a higher speed (perhaps with a friction wheel or pressure pad attached to another motor of some sort) and see if the spindle is behaving nicely. If not, I'd check the tighteness and the bearings.

As for the sound from near the handwheel my PM has a method to tighten a nut under the handwheel to remove play. Perhaps yours is too tight. After running the lathe at high speed for a while, stop and check for heat from friction.

As for bumping the speed control with your glove, if the problem comes from the potentiometer turning too freely you can add friction by removing the knob and making a washer that fits under the knob. I made a washer from a piece of felt for a knob that turned too freely. Some people turn off a lathe each time by turning the speed to zero but I don't like that method.

JKJ

[Roger Chandler]

The Delta "M" Series inverter is more modern and more advanced than the "S" Series inverters on Powermatics, Jets, and Lagunas. The "M" series does put off a little high pitched noise, [some call it "chirping" ]which seems to be mostly when the lathe is new. My G0766 was one of the first two or three shipped when the model first became available, and numerous others also noticed theirs made the same sound, so it is pretty much normal for this lathe, and my G0766 seems to have gotten quieter as the lathe was used over the months/years, and I hardly can hear that sound without putting my ear to the inverter box housing. I would not worry in the least, and you should just use the lathe and enjoy its fine performance. Seems new owners can be overly sensitive to the least little thing.

That being said, I recommend doing what I did before I ever put power to my G0766 for the first time. I went through the lathe, tightened every set screw, bolt, etc, and completely checked that everything was tight, and in its place. I learned that shipping across the oceans on a container ship induces a lot of vibration, and things can work themselves loose, and who knows if the factory workers took as much care as they should when they crated everything? A little problem seems to induce paranoia, and much apprehension.......everyone should go through their unit and carefully inspect and tighten every component. My G0766 has performed superbly since I got it in 2015.

[tom lucas]

Haven't there been some where the pulley on the headstock was not in the correct position causing the lathe to make noise? As I recall, it was rubbing against the indexing wheel or something like that. I would certain inspect the inside of the headstock housing.

The only "abnormal" noise I've ever heard on mine is when the set screw on the headstock handwheel would work loose and make a clicking-like noise at low RPMs. Tightened the set screw and noise went away. But, it would work itself loose again over time. Finally solved that by replacing it with a custom wheel by JT Turning tools for use with a vacuum chuck.

[John K Jordan]

...
That being said, I recommend doing what I did before I ever put power to my G0766 for the first time. I went through the lathe, tightened every set screw, bolt, etc, and completely checked that everything was tight, and in its place. ...

That's excellent advice and I do the same. Some years ago I bought a $12K diesel-powered zero-turn mower for the farm and in going through my pre-use check I found the hose clamp to the radiator coolant tank was not tightened and the coolant gone. Running it without checking likely would have damaged the engine. Probably good to recheck occasionally.

JKJ

[Brice Rogers]

David Bolson, if you are interested in pursuing this further, you may want to consider getting an "audio spectrum analyzer" ap for your cell phone. It will provide you with data regarding the frequency that you are hearing. Perhaps you are hearing some of the high frequency noise from the inverter that is high enough (16 kHz to 20 kHz) that many of us older folks can no longer hear. So perhaps we have the noise but don't notice it as much as you do.

On the GGMG, I recall a person posting about how you can make subtle changes to the inverter programming to lower audio noise. I think that the person's name may have been David Roseman (?).

In regards to using the F-0ff-R switch to turn off the lathe, there are people who advise against this and recommend using the speed control to more gradually slow down and stop the lathe. When the lathe is spinning and you go directly to the off position there is a fair amount of energy (EMF) that has to go somewhere. The lathe will free wheel longer than if you were to use the speed control knob. BTW, some people put in a braking resistor. Some of the higher end lathes like powermatic may already have the braking resistor installed. David Roseman also commented on that in the GGMG several years ago. I believe that it too needs a programming change to the controller.

[John Hart]

I did a little video of my lathe noise for your reference.
The ambient shop noise was about 30db and the reading was 30-55db over the range of 0-2000rpm.

https://youtu.be/_EHr4RysZoc

[Roger Chandler]

John, there is a very quick and very helpful modification you can do to get your chuck adapter to fit all the way back to your spindle shoulder as it should. Take a small file and hold it against the spindle boss [part where the adapter is now on your video] and run your lathe at about 500 rpm, allow it to take a smidgen off the spindle boss. It was machined to about 0.010 larger than most adapters on chucks. Take off a little, test the fit, take off a little more until it fits back to the shoulder...takes about a couple minutes.

After the chuck adapter fits securely all the way back, take some 220 grit, then 400 grit to polish the spindle. It will look like new, and all your chucks will fit as they should. The Grizzly chucks I have heard, fit right out of the box, so it may be a way they get sales of their chucks. Most G0766 owners have done this, and it is a great mod, and makes other brand chucks fit like they should.

[John Hart]

Thanks for the tip Roger....will do :)

[David Bolson]

I did a little video of my lathe noise for your reference.
The ambient shop noise was about 30db and the reading was 30-55db over the range of 0-2000rpm.

John - Thank you for doing that! That’s probably pretty close to what I found (see my post #14). My app read 61 at 2000 rpm’s, but my ambient started higher, our apps and phone microphones are different and probably not overly accurate to start with, etc.

I think my lathe is fine and apparently may even settle down to be a little quieter over time. Now I have to work on me, as my skills need some upgrading.

David

[John Hart]

John - Thank you for doing that! That’s probably pretty close to what I found (see my post #14). My app read 61 at 2000 rpm’s, but my ambient started higher, our apps and phone microphones are different and probably not overly accurate to start with, etc.

I think my lathe is fine and apparently may even settle down to be a little quieter over time. Now I have to work on me, as my skills need some upgrading.

David

That's great David. Good luck with the self improvement. Nothing seems to work for me. :)