Chuck wobble

[Roland Mann]

I've just treated myself to a Sorby Patriot chuck, and I'm having a few problems. I noticed it first when I was roughing a cylinder between steb centres. When I went to the skew chisel to plane the piece (which was not long and about 1 1/2 inches thick), I noticed a vibration mainly in the centre.

Looking at the revolving chuck there seems to be a visible wobble, very small but enough to vibrate the piece.

I have an old PC2000 chuck, and there is absolutely no wobble with this at all. I swapped it over to check, and it runs perfectly.

I have checked and rechecked to see whether there is any contamination preventing the chuck from seating against the back plate, but it's as clean as a whistle, as is the insert thread. There is no play in the bearings at all.

Any ideas?

 

[Argee]

I have checked and rechecked to see whether there is any contamination preventing the chuck from seating against the back plate, but it's as clean as a whistle, as is the insert thread. There is no play in the bearings at all.

Any ideas?

There's only one idea I have - send it back - visible run-out is simply not acceptable, nor fit for purpose.

You've covered all the other possibilities, so I'd say an e-mail or telephone call is next.

Ray.

 

[CHJ]

Agree with Argee on the get supplier to sort it.

Although your threads are clean and adapter insert appears correctly seated the alignment bore in the insert may not be a good fit on your lathe spindle chuck register.

Dimensions 1 and 2 HERE

If this is the case then the chuck is relying on the thread form for finding an approximate alignment, this can shift when a side load is applied.

 

[Simon M]

I bought a Sorby Patriot and had the same problem. I exchanged it for a Record Supernova 2 and still have the problem. I'm starting to suspect the lathe spindle is not true (it's a Scheppach DMT450 with M33 thread) but strangely there is no visible run-out with my faceplate however the threaded part on this is not as long as either chuck. I hadn't noticed any problem when turning between centres, had you?

 

[Simon M]

Sorry, I meant when using the drive centre, not the chuck!