Fixing a warped Longworth Chuck

[McKay Daines]

Hello all,

I purchased a Longworth chuck from a retiring turner, and the mortise where it is attached to regular chuck jaws is slightly out of round. I am thinking the best way to make it functional is to attach a faceplate to it, but I am stuck on how to make sure the faceplace is exactly centered on the chuck. Any suggestions or clever ideas on how I can make this work? Or is there a simpler solution I am missing?

Thank you,

 

[Jim Reynolds]

Do you think the Longworth chuck will close down concentric to the axis of rotation? If so then mount a piece of flatish stock, face it off and get it round, then mount the Longworth Chuck on to the mounted piece and tighten the Longworth Chuck. I’d bring in the tailstock for additional support (suspenders and a belt). You should be able fix the defective mortise. If the tailstock is in the way then secure the Longworth Chuck to the mounted plate. I’d probably use hot melt glue, but bolts or screws are a good alternative.

Your mileage may vary. Best of luck.

 

[Michael Brown]

I would second Jim's recommendation. I would attach a piece of Baltic Birch to a faceplate and turn it round to the max diameter of the Longworth, then attach the Longworth to the disc. You should then be able to true the surface and mount the Longworth perfectly centered.

 

[Bill Alston]

When I made a Longworth Chuck many years ago I was worried about using a wooden tenon on it right from the start. As a result I decided to use a faceplate for the build instead.
Jim's idea might work. If you can remove the tenon and find a way of temporarily mounting a faceplate on the tailstock spindle to offer it up to the chuck that could work as well?
I ended up discarding my Longworth chuck in favour of a Doughnut Chuck, mounted on a faceplate of course! I find it a very secure way of reverse mounting stuff.