Grizzly 4003G Lathe Chatter Problem

Jamespvill

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Hello All!

So I have had my Grizzly 4003G since August of 2012 and It had been an absolutely fantastic machine. It is used multiple times a week for at least an hour per session. It had never been crashed, tipped, or mangled in any way shape or form. I would like to think that I keep it in pretty good condition as I need the tolerances as tight as possible (As we all do).

Just last week I was turning some 6061 aluminum and noticed that there was lots of chatter marks on my piece. I was taking light cuts and using fluid. I have never had chatter marks on aluminum before! I just figured it was some bad aluminum or something of that nature...:thinking:

I was in a rush, so didn't put much thought into it. But today I was turning some stainless and there was huge amounts of chatter on the piece, and audible squealing.(I've never had problems with SS before) So I reset everything, fresh cutter edge, and tried again. Same results...So I moved onto mild steel, then aluminum again and the same horrible chatter. My stick-out was only an inch or so and even when I put my live center on it, the piece still had chatter marks.

I double checked all of my gibs, rechecked my tool height, made sure every nut and bolt was tight on the machine, double checked it was still level, and pulled out my favorite machining 12L14 stock to confirm...Same chatter!!! :panic:

So...It appears as though I am in need of some serious help! Both with my machine and mental state at the moment! (I don't want a $3,000 paperweight!)

I'm afraid it may be bearings that are causing my problems, but I have no idea how to approach confirming that is the problem or how to replace the darn things...I'll admit I have very, very little knowledge of bearings at all, and am a bit intimidated by the though of pulling apart my Lathe.

Thanks in advance for anyone providing some help!
 
Don't be afraid to call Grizzly's service dept. if you can't find something simple going on (M-F eastern time zone.) Those guys are super-helpful and may have additional information about your machine that you don't have. They once sent me an internal document for my prior benchtop mill that wasn't in the manual. Something about adjusting the spindle, I seem to recall. Hopefully it's just something that has gotten loose that's either not obvious or so obvious you aren't seeing it.

-Ryan
 
I'm not taking the time to look up that model. BUT,if the lathe is a cabinet model and sitting on concrete,there's your problem. When I bought my 16 X 40 Grizzly in 1986,it ran like a bunch of small parts vibrating down a chute,and BADLY chattered metal. I found out when driving oak wedges under it in leveling it,the noise and the chattering stopped the instant I got it off the concrete floor,and onto the oak wedges.

Now,my lathe sits on Mason rubber pads,and has worked just fine and quietly ever since. I hope this is the answer to your problem. If it is a bench lathe,what is it sitting on? Get some hardwood under it,I'd suggest. Even not real thick hardwood will help.

P.S. I just saw another thread with pictures of the same model lathe. It is sitting on a cabinet. Do try getting the bottom of the lathe out of contact with the floor if it is concrete. I don't know why Grizzly lathes react that way (maybe all of them don't).but that was the solution to my problem.

Please post if my advice works. I do not think the Grizzly techs know the solution to this problem,though in 1986 I did tell them how I solved my problem. They were about to send me a new headstock!!
 
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Sounds like it started suddenly.
Any changes to the environment, setup, or tools?
 
Okay, So I put some wood underneath the lathe to get it off the concrete, re-leveled and unfortunately the problem persists... It's been running on the concreter floor for the last year and a half with no problems.

Here are the chatter marks.

image-1.jpeg


I have been working mostly in aluminum lately, so audible chatter isn't too noticeable and I have been media blasting all my parts so finish from the lathe hasn't been a concern for the last two weeks. The problem may have started up to two weeks ago but I just didn't notice it at the time. All my tooling is the exact same and my setup, location and environment are all the same as they were 2 months ago.


I should probably stop stressing and just wait until tomorrow to give Grizzly tech support a call, they have been very helpful the last few times I called. But I think we all would all react about the same when our perfectly accurate machine starts putting out crap finishes.

Regardless, any more suggestions would be gladly accepted!

image-1.jpeg
 
Common problem...

The jib in either (or both) the crossfeed and compound need to be adjusted.

NOTE: If you remove the crossfeed from the unit to clean the jibs, wear gloves and handle it carefully. The dovetails have very sharp edges and that's a 40lb block of metal. Last year, I was doing the same thing and in the process of carrying the crossslide to set it down, it stumbled from it's resting position and in the process of steadying it, I badly lacerated the inside tips of three fingers. 32 stitches and significant nerve damage that persists even now and 2 months of very sore/sensitive fingers to the point I could do almost nothing with that hand.

Ray
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Its a hail Marry but did you check the chuck? It sounds like you have done everything else so you might remove the chuck, clean inspect and reinstall to check that the cam bolts are still tight and turn them in a turn if you find some too loose. Check motor mounts, motor pulley. Does it chatter at all speeds and other gear box combinations?
 
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Ray, Ouch! I remember seeing some pictures of your hand healing when I first joined the forum but never got the whole scoop! Sounds a bit like a fight that I had with some 304 SS swarf, but I think I was lucky with that one...very little nerve damage for me.

I thought it was gib problem to start with so adjusted them, then readjusted again until they were so tight I could barely move them, unfortunately chatter was still very present.



coolidge, Just this morning I had that Idea, so I went out, popped the chuck off, tightened everything more, cleaned everything and put it back on. Alas...there is still chatter. Also, whether it's at 200 rpms or 1000 I get chatter at a 5 thou depth of cut or a 50 thou

So far the lathe is winning, But that will change soon! I'll give grizzly a call in the morning and with the combined knowledge present here I do believe I will have a lathe running top notch again by Wednesday! (Gotta keep positive, right?)
 
Try rotating the compound and take the cut at 0, 45 and 90 degrees and see if that makes the chatter go away. If it does, it's the jibs. The reason I pulled mine apart was because swarf was caught-up in there from turning brass and bronze. That stuff crumbles into little chunks and gets everywhere and as a result, I could not adjust the jibs -and they seemed snug. After cleaning and properly adjusting, the problem went away.


Ray
 
Okay, So I put some wood underneath the lathe to get it off the concrete, re-leveled and unfortunately the problem persists... It's been running on the concreter floor for the last year and a half with no problems.

Here are the chatter marks.

View attachment 73345


I have been working mostly in aluminum lately, so audible chatter isn't too noticeable and I have been media blasting all my parts so finish from the lathe hasn't been a concern for the last two weeks. The problem may have started up to two weeks ago but I just didn't notice it at the time. All my tooling is the exact same and my setup, location and environment are all the same as they were 2 months ago.


I should probably stop stressing and just wait until tomorrow to give Grizzly tech support a call, they have been very helpful the last few times I called. But I think we all would all react about the same when our perfectly accurate machine starts putting out crap finishes.

Regardless, any more suggestions would be gladly accepted!

I see you are using a 3 jaw chuck,is it possible your jaws are worn and only griping at the back.
 
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