Workholding in the lathe

[Terk]

I need to machine the ends of some leadscrews and would like advise on how to protect the threads when turning. I'll be using a 3 jaw chuck (and a steady rest for the long screw).

Thanks for any tips you can give me.

[fpworks]

G10 inserts on your jaws.

Make sure they are laterally keyed to your base jaws and use a threaded insert in the G10. (recommend keensert type)

Sorry about this recommendation if you are not doing very many parts!

Justin

[ctate2000]

Buy or make a nut to hold in the jaws. Use another as a jam nut to secure. Collet would be perfect. If it is a true lead screw and has Acme or Square threads don't worry about it. Hold it in the jaws and go easy.

[widgitmaster]

just bore a hole in a short bar of aluminum, the exact diameter of the thread OD.
Then saw a slot through one wall, and insert the screw.
Close the 3 or 4 jaw chuck on the aluminum, it will clamp the thread as true as your bore!
Then you can machine the ends to suit your needs!

Eric

[widgitmaster]

Oh yea,

Make a plug for the end of your spindle, with a loose bore for the screw to stay true to center, and do not let it protrude more than a foot, or it may bend and whip and hurt someone!

I use a piece of PVC pipe to support long bars on the end of my lathe!
A 2x4 stand with a hole at the same height as the spindle bore is all you need!

[Adobe Machine]

Check the thread " Manual to CNC lathe conversion. I have pictures of exactly what " Widgitmaster" has explained above. It works, its safe, its accurate.
If the material is hardned all the way through you should use a 1/64 radius cutter with a little positive rake, such as a CMNP or CNMG carbide insert,this will give you a good finish and decent depth of cut.

Adobe (old as dirt )