Lathe cross slide conversion to a ball screw

[tonyfoale]

I'm certain elimination of backlash is part of that, with a common leadscrew subject to vibration, wear and imperfect mating surfaces.
It's also why climb milling [on ball screws] is OK, even by hand.

My mill had ball screws from new and I almost always use climb milling without problems. That is both manual and CNC.

[dagrizz]

Paul Compton pointed out in the Youtube comments that LH ball screws are rare because these screws are mainly used in CNC machines and it is simply a matter of software as to which way they turn. So there is no need to make both RH and LH screws.

Umm, how'z about turning the ballscrew nut around. Then it'd run backwards! Same-o, same-o, right?

[tonyfoale]

Umm, how'z about turning the ballscrew nut around. Then it'd run backwards! Same-o, same-o, right?

I am at a loss to decide if this is a serious comment or not.

[machining 4 all]

Its project is interesting, it is a pity that you will have to get used to the inverted advance of the cross slide (not that this is the end of the world). A search on a famous chinese sales website could have helped before the purchase...

[dagrizz]

I am at a loss to decide if this is a serious comment or not.

Definitely not serious; I just couldn't resist... Actually, I'd consider this upgrade for my Taiwanese 12 x 36, especially if the LH ball screw was available.
[edit]
I just checked at Thompson; they list a 5/8"LH w/ 0.2 lead, 6' long [https://www.thomsonlinear.com/en/product/190-9099]
The nut [https://www.thomsonlinear.com/en/product/8106-448-037] needs a screw-on flange [https://www.thomsonlinear.com/en/product/8105-448-002]. You'd have to machine the shaft to fit, and I haven't researched the fixed & floating bearing options.

[tonyfoale]

Its project is interesting, it is a pity that you will have to get used to the inverted advance of the cross slide (not that this is the end of the world). A search on a famous chinese sales website could have helped before the purchase...

I am getting used to it, slowly. The truth is that I never gave any thought to the hand of the thread, I just ordered a screw assembly. Since then I have searched for LH versions without success.

[tonyfoale]

I just checked at Thompson; they list a 5/8"LH w/ 0.2 lead, 6' long [https://www.thomsonlinear.com/en/product/190-9099]
The nut [https://www.thomsonlinear.com/en/product/8106-448-037] needs a screw-on flange [https://www.thomsonlinear.com/en/product/8105-448-002]. You'd have to machine the shaft to fit, and I haven't researched the fixed & floating bearing options.

Many thanks for that. BTW your links returned "product not found" responses but if I copied and pasted the PNs from your links in their search box it had no problem finding them. The screw on nut mounting is like I have on the Z axis of my mill, it would have been much easier to fit on the lathe than the flanged nut that I got.

[tonyfoale]

Mariano found some LH versions of the same size on Aliexpress. I'll order one. here is the link for anyone else who is interested.

https://www.aliexpress.com/item/1005...archweb201603_

[gatz]

...the sizes being 16 & 20 mm diameter?
sometimes hard to understand Chinese specs

[tonyfoale]

...the sizes being 16 & 20 mm diameter?
sometimes hard to understand Chinese specs

1605 and 2005 seem to be fairly standard specifications from what I have seen. !6 or 20 mm as you surmise, both with 5 mm pitch.