Power feed shafts do not spin at high rpm so will not sling the oil out of the trough so not a lot of topping up required, no grease sounds sensible.

Martin

Hello Roger.

This is the back of the apron of my Chinese 13×30 lathe, which is probably very similar, if not identical, to yours. The worm gear has to be lubricated manually, the only lubrication on it when delivered was the filth that the factory carelessly slapped on.

Every now and then I simply squirt some oil onto the worm, which last quite a while and works well. But there is the problem of swarf dropping onto the worm and wheel.

My lathe came fitted with telescopic leadscrew covers, but these had to be removed so that the carraige could travel further along the bed to make the lathe usable. But without these covers swarf falls onto the leadscrew and then off onto the worm drive.

There is just enough room between the leadscrew and the worm wheel gear to fit a simple thin metal plate cover to the apron to shield the gears from contamination. This is a job I have been planning for quite a while, and when I am at it I planned to also fit a pipe leading to the worm gear at one end, with the other end accessible from the side of the apron. This will make lubricating the gears a lot easier than trying to peer down the back of the apron while trying to squirt the oil in the correct place. I think oil is preferable to grease on these gears.

Edited By Lathejack on 01/01/2016 16:17:42

Hi Roger.

The design of the carraige interlocks is very simple and quite clever, and can work perfectly well. The only problem with it I have encounted on these machines is that the factory responsible for the assembly of these lathes sometimes use whatever piece of grotty off cut they find to make the flat bar lever at the back of the apron that locks the feeds.

On my lathe that interlocking lever was made from a piece of very battered, bent and corroded scrap. The corner that engages in the sliding shaft groove was badly formed with a hand file. So it worked, but only just, the lever in the photo is a new replacement I made.

It's a good solid system. There is a sliding shaft that sticks out the front of the apron and meshes with the feed control lever, the control lever slides the shaft in and out. This shaft passes right through the apron and internal gears and sticks out the back. When the power feed control lever is in neutral the deep groove machined into this sliding shaft is inline with the interlock flat bar lever at the back of the apron, the other end of the flat bar is attached to one of the leadscrew half nuts. This allows the half nuts to be closed because one end of the flat bar swings into the shafts groove, this then prevents the power feeds from being simultaneously engaged because the shaft is now prevented from sliding in or out.

When power feeds are engaged this slides the shaft in or out so that the groove in the shaft is no longer inline with the interlock lever, so this now prevents the half nuts from being engaged because the lever can't move far enough, it just buts against the shafts outer diameter.

Edited By Lathejack on 02/01/2016 13:29:58

Edited By Lathejack on 02/01/2016 13:33:16

Yes, as you thought the cast lug is bored to form a guide to keep the leadscrew straight and central to the half nuts. The Wilson lathe apron shown in the post above by Ega appears to have one either side of its single half nut.