I remember seeing ads of companies who sell lathe chucks who will thread your chuck to match your lathe. Can’t find these companies now. I have an old lathe with a 2 1/8 x 8 tpi spindle. None commercially available or on the used market apparently. And many have told me I can bore and thread the chuck myself. My chuck is 0.006 out of round so if I bore my new one on it it will be off center too. Anybody know a source?
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Custom Threaded Chuck
- Thread starter CJ5Dave
- Start date
- Joined
- Jun 7, 2013
- Messages
- 10,094
If it were me, I would make a thread plug gage to exactly the wire size (or thread mike size) of your spindle and buy a rough cast or rough machined cast iron backplate, and bore and thread and face it to fit the gage, then thread it onto your spindle and machine it to fit your chuck, if the jaws then run out, regrind them to run true.
Please tell me how a piece clamped in a chuck .006 off center can be bored and threaded true and center?
Also, my chuck (lathe from 1942) has 2 pinions out of three missing (can only tighten one jaw) and the jaw threads are worn really loose. Needs a new chuck. Some things can’t be fixed or are not practical to fix. I
Also, my chuck (lathe from 1942) has 2 pinions out of three missing (can only tighten one jaw) and the jaw threads are worn really loose. Needs a new chuck. Some things can’t be fixed or are not practical to fix. I
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- Joined
- Mar 25, 2013
- Messages
- 4,617
If you get the threads cut to size it won't matter that they are off center. When you screw that new back plate on you can then turn and face it so it is perfectly concentric before mounting the chuck. In fact all back plates are off center from the factory. When you attach them and true them up on your lathe they become concentric.
I have never cut threads. I have never used a boring bar. Usually I need several fails to learn a machine process. Can’t afford to ruin 5 new chucks right now.
Like I asked, does anybody know of a chuck mfg/supplier that will prethread a chuck?
Like I asked, does anybody know of a chuck mfg/supplier that will prethread a chuck?
- Joined
- Mar 25, 2013
- Messages
- 4,617
Sorry, I was just answering post #3. What back plates are on the chucks now? Could a local shop do the threading if you don't want to?
BTW if these are somehow chucks with integral mounting as in no back plate, and you try to thread the chuck body, no shop will be able to get this done accurately. Examine your chucks carefully and see if they have a back plate that comes off the chuck body.
Also, if it is a 4 jaw independent then runout does not matter. If it is a scroll chuck, getting less than .002" runout would be OK.
BTW if these are somehow chucks with integral mounting as in no back plate, and you try to thread the chuck body, no shop will be able to get this done accurately. Examine your chucks carefully and see if they have a back plate that comes off the chuck body.
Also, if it is a 4 jaw independent then runout does not matter. If it is a scroll chuck, getting less than .002" runout would be OK.
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