screw chuck screw broke

[byron constantine]

I have a 1642 and was using the screw chuck on an ash bopwl and as i was starting to form the bowl the bowl fell off the lathe with the screw part still in it. What made it shear off as i was not in an agressive cut?
Anyone have this happen to them? Also where can i get another one>
The chuck is a super nova.
Thanks, Byron

[Dick Strauss]

Byron,
My guess is the screw got hardened too much and became very brittle (through poor manufacturing processes). Contact Nova and see if they'll send you a new one free of charge. Normally the wood will strip long before the screw shears.

[Steve Schlumpf]

Byron - that's the first time I've heard of that happening! I agree with Dick - contact Nova as I am sure it has to be a product defect of some type!

[Stan Terrell]

I had that happen with a VicMark chuck about a year ago. Was working on a soft maple bowl. Not much stress at all. I just ordered a new one from Craft Supply.

Stan

[Gordon Seto]

That's a scary thought. We don't necessarily use the tailstock when using a screw chuck. When a single screw snaps, there is no warning. Even the chance is remote, but it is still there. The consequence can be very serious.
It may be safer using the faceplate or faceplate ring. Not all the screws would break off at the same time. It may not be able to shut off the lathe in time; hopefully still able to step out of the firing line.

[Bernie Weishapl]

I had one break on the oneway chuck I have. I quit using them on my other chucks and strictly use a faceplate now.

[Gary Herrmann]

I would doubt anyone could have a catch bad enough to break a screwchuck screw. Well, maybe spinning a 400 lb blank and deliberately trying it...

After using screwchucks for awhile, I went back to faceplates. Screws come out easy and I like the redundancy.

[David Drickhamer]

I make my own screw chucks and have never had a problem. I take a piece of baltic birch about 2" in diameter (size doesn't matter), chuck it up in a 4 jaw chuck and drill a hole through the center. Then screw in a large self tapping screw and you have your screw chuck. Use it with your 4 jaw. Make several, they're cheap and you can change the screw or throw them away after a few uses.