Adaptor Question

[David DeCristoforo]

So after searching everywhere and finally giving up, I accidentally stumbled across my Glaser screw chuck (I knew I still had it!). I got this back in '85 when I had a Hegner lathe on loan in my shop. They took the lathe back but let me keep the chuck. Only problem is it has a 1 1/4" 8TPI bore and my Delta lathe has a 1" 8TPI headstock spindle. I recall seeing an adaptor that would work for this but I can't remember where! Can anyone point me in the right direction?

Thanx
DD

[Alan Zenreich]

Try Hartville Tool.

Search their lathe accessories for

Hold Fast Spindle Adapter - 1" x 8TPI Female To 1-1/4" x 8TPI Male

[George Clark]

I think one of these will fix you up.

http://www.woodturnerscatalog.com/store/Lathe_Accessories___Spindle_Accessories___Spindle_ Adapter___spindle_adapter?partnerid=googlebase

[David DeCristoforo]

Thanx ya'll. I was thinking I had seen one that would fit inside the 1 1/4" bore and shim it down to 1" but now I cant seem to find that anywhere. I guess I'll have to go with one of the "big ones"...

[David E Keller]

Just send it to me... Should fit the mustard like a glove!:D

[David DeCristoforo]

I got the adaptor today but it's weird. The male end seems to be the right size and thread but it only goes in about 3/4 of the way before it binds. So the chuck won't seat. I thought it might be a metric size but I can only find a 33mm metric size with a 3TPI thread and that would not even be close. I checked the actual inside measurement of the bore on the chuck and it measures 1.375" not 1.25"?!?! Am I going to need a machine shop? The adaptor is not something I'm really happy with anyway because, even if it did seat, it adds several inches to the length of the chuck which leaves the screw hanging out there pretty far. Anyone got any idea of what I have here?

Thanx
DD

[David E Keller]

Not sure this is helpful, but this website lists the Hegner spindle size at M33x3.5

www.teknatool.com/products/Chucks/Identifying%20Lathe%20Spindle%20Thread.pdf

If the chuck fit the old lathe, then maybe that's the size.

[David DeCristoforo]

"...this website lists the Hegner spindle size at M33x3.5..."

that's whats strange, or, at least one of the things that is strange. The inside bore of the chuck does not measure 33MM. Does 3.5 refer to the thread count per CM? It can't be per inch if it's metric... no? I guess I could order one of those and try it for fit. Maybe I can exchange the one I have...

[Don Geiger]

Contact Sharon at Best Wood Tools (931-788-0429), in Crossville, TN. They manufacture a very nice line of adapters. I have several so I am prepared for using various lathes when demonstrating at clubs and symposiums.

Don Geiger

[Jeff Nicol]

David, On most all threads there is a bit of play or backlash that will be taken up when you tighten the nut, chuck or whatever until the flat mating surfaces on each meet. If you are measuring just the hole in the chuck and not to the outer width of the threads you will get a incorrect measurement, and like I said if you measure to the complete depth of the threads it should be a bit bigger than the stated size 33mmX 3.5 or 1 1/4" X 8tpi. I think on the metric the 3.5 is the pitch of the threads which correlates to certain threads per. If the threads were cut perfect we would never be able to thread things together, that is why on CNC machinse and anything that has linear movement a nut with a spring or two piece nut is used to be able to take up the backlash to make more precision movements and cuts.

So Doc Keller is probably correct on the Hegner threads.

Good luck and I think a machine shop could make you a bushing that will do the step down proceedure for you.

Jeff

[David DeCristoforo]

Jeff
I kinda figured that out although it took my slo brain a while! I was bolloxed by trying to measure the bore in the chuck when I should have been measuring the spindle which, of course, I don't have. I ordered a 33MM adaptor and will return the 1 1/4" one. But I am also going to get an internal bushing made at some point just to get the chuck down on the spindle where it belongs. I don't understand why these are not available. Would not be much different than the adaptor for the Nova or any other chuck. Go figure. Anyway, thanks to everyone for all the "hand holding"...