Adjusting lathe saddle gib-strips

I've stripped my ageing Chinese mini-lathe, prior to cleaning after a long period of non-use, and want to be sure that I understand the purposes of the screws in the gib-strips on the underside of the saddle before I re-assemble it.

Am I right in assuming that the adjustment is made as normal with the grubscrews/locking nuts and that the socket headed screws are merely for location purposes & as such the latter should be only be tightened sufficiently to hold the strips in place?

Brian

Best wait for some one else but from memory some use a push pull arrangement so your hex heads push and the nuts pull. So yes in effect they are just holding them in place but the idea is to get them locked in place. They will need bit of care setting up.

John

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There's a pretty good explanation of the adjustment on littlemachineshop.com

The gib strips are brittle cast iron and they can break easily. Many have dispensed with the adjusting screws and shimmed the gibs to get a nice sliding action. It is tedious and takes a long time to do but once done there is no need for further adjustment for many years.

It is also worth considering replacing the screws with studs as described here:http://www.toolsandmods.com/lathe/mini-lathe-saddle

Mike

Is there a way to lock the slide in position - when milling, perhaps?

If not, would now be a good time to arrange something?

Cheers, Tim

Thanks chaps - it all seems to confirm what I thought.

I must bookmark the littlemachineshop link, as my original manual (long since lost) was written in bad 'Chinglish' & didn't have anywhere near the same amount of information.

Just as an aside, there are a couple of grubscrews in the top of the saddle. First of all I thought they might have been covering lubrication points but when I removed them, the holes appeared to be blind. My only other idea is that they're fixing points for some attachment. Can anyone confirm or deny that?

Brian

Brian,

those 2 holes on the saddle are for fitting the travelling steady

When I sorted out an Optimum micro lathe for a fellow member on here some time back, I did away with those fiddly, flimsy grub screws and fitted steel shim in the gap so the gib strips (anti-lift plates really) could be nipped down firmly and sit parallel to the bed way they run on. The bed way needed a bit of a clean up with a dead smooth file and slip stone to get rid of burrs and machining bumps. It worked very nicely after that.