Ballscrew tolerances and real world performance

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WJH
Posts: 1373
Joined: Sat Jan 16, 2010 9:29 pm
Location: Florida

Re: Ballscrew tolerances and real world performance

Post by WJH » Sat Mar 10, 2018 9:23 am

Marty_Escarcega wrote:
Sat Mar 10, 2018 9:17 am
WJH wrote:
Thu Mar 08, 2018 1:26 am
Bill Shields wrote:
Wed Mar 07, 2018 8:00 pm
glass scales are a problem on lathes that small. many companies sell other than 'glass scales' that are much thinner...the big problem, even if you CAN get the glass scale on the lathe is loss of tailstock positioning toward the chuck when working with very small parts.

I would be surprised if you can get a ball screw under the slide of a lathe that small (that was not initially designed to support a ball screw).

everyone thinks that you can take a 'hand wheel' lathe and stick a control on it and get good positioning...

please look before you leap....
This is the constant struggle in my life. While on the road, I dream big, and have to reground myself when I get home and am actually able to measure things... I’ve been thinking of plans B, C, and D just in case... I WILL be able to get a ball screw in there, even if unconventional.
There are kits made for the small benchtop lathes.
Again, don't overstress about accuracy of the screw. Your little lathe will be fine with C7. Just get it together and learn....have fun.
Last night was able to measure things. The current leadscrew is 20mm diameter, so ordered a 20mm x 05 ballscrew and nut, crosslide is 12mm, so ordered a 12mm x 04 pitch ballscrew and nut off eBay. Both are P7, from China. Going to take a while to get here. Both have unmachined ends. Might end up being a good exercise for my tool post grinder, or cermets.

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