drilling brass?

[BillTodd]

Irving,

I was thinking about you method of backlash removal; It might be worth arranging things so the bulk of the thread is pushed or pulled towards the handle of the cross slide, rather away from it, since most turning is external and the cutting force will be in that direction.

[irving2008]

Bill,

The plan was that the screws would be on the side away from the handle so they can be adjusted from the outside, and this would be the shorter 1/3 of the nut (approx) as per diagram

[BillTodd]

Bill,

The plan was that the screws would be on the side away from the handle so they can be adjusted from the outside, and this would be the shorter 1/3 of the nut (approx) as per diagram

So, your adjustment screw will squeeze the threads? If so, it means that while outside turning the force will be taken via the adjustment screws to the cross-slide. I modified my Southbend in a similar way except, the adjustment screw were threaded into the split portion (I simply sawed part of the way through the nut) , so the adjustment separated the parts IYSWIM.

[irving2008]

i see what you mean, and i was going to do it that way, but i was told there was a risk of the nut splitting if i did this (being old brass) - the amount of backlash is significant... it might need quite a gap!

What I had planned to do is saw it with a fine saw, then reassemble and check the backlash. then mill a small amount off the fixed portion such that when the screws are done up its a little overtight.. then shim it back. Its only until I can make the new nuts and screws so only has to last another, ummm, year or so... these have lasted 100y already!