Where to buy lead screws in europe?

[DennisCA]

I have got a worn lathe and I am planning to start replacing the lead screws and nuts eventually.

I am having some issues though because my lathe was made in Sweden and used an unholy combo of metric and imperial. The main lead screw with which you both single point thread and drive the carriage (bad design!) is a 20mm 8 TPI lead screw.

Now the diameter is less important as long it does not differ too much as I will have to make new half nuts anyway, I suppose I could use a 3/4 x 8 tpi lead screw just as well since I will be remaking the half nuts.

But it's been difficult to find a lead screw in europe that is threaded in TPI. I'd like a precision screw that is preferrably ground and hardened so it will last, though I will want to be able to machine it. The pitch is most important though or the gear box and all the change gears will no longer thread correctly. I am gonna need less than a meter of it.

For the cross slide it's less important, I could use any roughly suitable lead screw there as long as it's close enough. Might just replace it with the closest metric assembly I can find. I am contemplating acetal or delrin lead screw nuts too, though that is a bit off topic.

The cross slide slop though is far worse than the longitudinal feed so I will address it first, makes threading a PITA.

 

[Milkybars]

https://www.abssac.co.uk/p/Legacy+Linear/ACME+Leadscrew/101/

 

[Milkybars]

The cross slide you could go with https://shop.ondrives.com/1-start-steel-leadscrews (they do corresponding nuts)

 

[500e]

There is an interesting thread on
Making Acetal leadscrew nuts the easy way
https://bbs.homeshopmachinist.net/
Think you will have to become a member
The site search is ?

 

[pressbrake1]

https://www.abssac.co.uk/p/Legacy+Linear/ACME+Leadscrew/101/

6 thou per foot accuracy is bad.

I’d try stanko service in Russia
Screw machine in turkey
Halifax rack and pinion

 

[pressbrake1]

Hardened and thread ground is going a bit far and expensive!
How long does your leadscrew need to be? I don’t have a thread whirl but could screwcut one. My friend in Brazil did a beautiful job making one on a tiny lathe

 

[DennisCA]

I might have been getting a head of myself. I assumed the screws were worn because I have read and been told by people that this is what happens. Got a worn nut then 100% your lead screw is also worn.

But today I disassembled the lathe to get at the screws and I checked them with a thread gage and a caliper and to be honest they seem basically unworn. Seems as if I got lucky perhaps, all the wear seems to be on the nuts.

I also identified the cross s lide lead screw as being a 3mm pitch, so imperial longitudinal feed, and metric cross slide feed...

I wanted ground screws because a smooth screw is better if I am going to use acetal nuts.

 

[pressbrake1]

Imperial leadscrew work better!

 

[DennisCA]

Dunno if I see any difference between them wear wise. But the oddness continues, the diameter of the cross slide screw is imperial 7/16ths (11.1mm) despite having a metric 3mm pitch.

 

[grim_d]

Dunno if I see any difference between them wear wise. But the oddness continues, the diameter of the cross slide screw is imperial 7/16ths (11.1mm) despite having a metric 3mm pitch.

Not that unusual, especially on old machines that were initially made all imperial.

What lathe is it?

 

[DennisCA]

Well this lathe was made in Sweden from factory like this. It's a Rexvalter VF-118. Based on a South Bend 9 style lathe. So some bits are metric and others are imperial. It can cut a large number of threads, both imperial and metric.