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View Full Version : Help or advice required please. Converting lathe cross slide to ballscrew.



Betnorm
11th Oct 2020, 11:40 AM
I hope I am in the right area of the forum to raise this question. I have a TM1960G lathe which has a worn lead screw in the cross slide and would dearly love to convert it to a quality German ballscrew set up. I have not the slightest knowledge of how to do this but I am willing to listen to any and all who can educate me to achieve the desired out come? Regards All Norm

caskwarrior
11th Oct 2020, 11:53 AM
A ballscrew can be backdriven because of the low friction so it will need a decent way to lock the slide once it has been advanced. Also the nuts are quite large and can be hard to fit.

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snapatap
11th Oct 2020, 12:22 PM
Unless you are doing a cnc conversion it wont work. as said above a ball screw will backdrive, on a CNC this is overcome by the motor holding the screw in position.

Betnorm
11th Oct 2020, 12:37 PM
Unless you are doing a cnc conversion it wont work. as said above a ball screw will backdrive, on a CNC this is overcome by the motor holding the screw in position.
Thank you kindly for this advice. I had thought I was heading in the right direction to eliminate most back lash and variation. Seems as if a new lead screw is the only answer? I am surprised no one has come up with some way around this problem ? Would some form of indentation or pawl/lock on the dials be possible or even a magnetic or electrical feed lock. Regards To All Norm

snapatap
11th Oct 2020, 01:48 PM
why do you think your screw is worn? I have used a lot of very well used lathes and never encountered one that had a screw so worn it was unuseable.

caskwarrior
11th Oct 2020, 03:30 PM
A ballscrew can work on a manual machine but you have to have an absolutely positive lock.

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Michael G
11th Oct 2020, 06:35 PM
That lathe seems to be in current production, so if you contacted H&F, you should be able to buy a new leadscrew for it. If the leadscrew is badly worn you will may need to replace the nut as well. If you are lucky, the wear may mostly be on one part (nut or screw)

Michael

elanjacobs
11th Oct 2020, 10:42 PM
Would some form of indentation or pawl/lock on the dials be possible or even a magnetic or electrical feed lock. Regards To All Norm
That sounds like a solution looking for a problem. Indentations mean that you could only move in fixed increments, which is not ideal, and those steps would need to be fairly large to engage positively, which is even less ideal.

The leadscrew had been used on basically every lathe since forever, why go adding complexity where it doesn't need to be?