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Vibrating lathe
Posted: Mon Nov 16, 2009 10:55 am
by tbinggeli
When I am trying to turn a cup or a scoop (probably a bowl as well), I can turn the outside until round and it runs totally smooth. As soon as I start trying to hollow out the cup, as soon as the chisel hits the wood it starts vibrating really bad and bouncing all over the place. If I move the chisel away from the wood as soon as it releases the wood starts spinning perfectly round again.
I am using the Nova G3 chuck and there is no wiggling in the chuck. The shopsmith seems to have a little play when I jiggle the arbor that the chuck is attached to. Is there a way to tighten that down. Is there something else that is causing the peice to vibrate like crazy. I am able to muscle it and carve out the middle, but it gives me a headache and I am worried about breaking my piece.
Thanks for any info!

Posted: Mon Nov 16, 2009 12:01 pm
by RobertTaylor
two things that i suggest checking. 1. make sure you snug down the spindle lock to eliminate any play. 2. make sure that your tools are sharp and are "cutting" the wood not you are not forcing it to cut.
Posted: Mon Nov 16, 2009 12:33 pm
by paul269
I am assuming you are getting the vibration when you try to cut the end grain. If so then cutting the end grain is difficult and requires sharp tools. The tool may not be cutting and therefore catching the wood and “bouncing” off of the end grain.
Have you noticed any tear out of the wood?
You don’t mention the type of wood, the tool size or speed.
So try smaller sharp tool, faster speed, and smaller shallower cuts.
Posted: Mon Nov 16, 2009 12:46 pm
by tbinggeli
1. make sure you snug down the spindle lock to eliminate any play.
How is that? do you mean the quill lock? Where is the spindle lock?
2. make sure that your tools are sharp and are "cutting" the wood not you are not forcing it to cut.
I thought the same thing. I double checked, but it happens when I'm not cutting just touching the wood.
Posted: Mon Nov 16, 2009 12:50 pm
by tbinggeli
paul269 wrote:I am assuming you are getting the vibration when you try to cut the end grain. If so then cutting the end grain is difficult and requires sharp tools. The tool may not be cutting and therefore catching the wood and “bouncing” off of the end grain.
Have you noticed any tear out of the wood?
You don’t mention the type of wood, the tool size or speed.
So try smaller sharp tool, faster speed, and smaller shallower cuts.
These tools are very sharp. There isn't much tear out. I am using a soft oak. I am cutting the end grain, but again it's not even when I am cutting. It happens when I just touch the wood with the chisel before I adjust the angel to begin cutting.
I have tried faster speed, but it usually just seems worse when I do that. Enough to loosen the handles and make them unscrew and fall out.
Posted: Mon Nov 16, 2009 12:51 pm
by mickyd
Any play if you wiggle the bowl toward the back and front of the machine firmly by hand?
Posted: Mon Nov 16, 2009 12:54 pm
by tbinggeli
mickyd wrote:Any play if you wiggle the bowl toward the back and front of the machine firmly by hand?
There is no play wiggling toward or away from the headstock, just side to side and up and down.
Posted: Mon Nov 16, 2009 1:03 pm
by mickyd
tbinggeli wrote:There is no play wiggling toward or away from the headstock, just side to side and up and down.
Any idea how your quill bearing(s) are?
http://www.shopsmithacademy.com/SS_Archives/SS124/SS1224_Shopsmith_Reborn_Pt4.htm
Posted: Mon Nov 16, 2009 1:08 pm
by tbinggeli
No idea... but thanks for the link. I will check as soon as I have time.
Posted: Mon Nov 16, 2009 1:20 pm
by greitz
If you push against the end grain with the back end of the tool handle, does it vibrate? It shouldn't. If it does, then something's wrong with the way the wood's inserted into the chuck, the way the chuck is attached to the spindle, or the spindle is slipping on its teeth somehow.
What chisel are you using? If you're trying to hollow end grain with the same roughing gouge you use to round the outside, I don't think it's "pointy" enough to hollow without catching the tool's "wings". Try a smaller spindle gouge, preferably with a fingernail grind. Or another tool specifically meant for hollowing.
A picture of your chisel and setup might help.
Gary