Why are gib screws so small

[moerman]

Succes!! I drilled the 3 mm holes in the gib strip. I then turned a 6 mm length of the M4 screws to about 2.9 mm. The screws fit snugly into the dovetail and gib strip, probably because the alignment is not perfect. But what a difference! The adjustment is far less critical. tighten all screws and loosen them all 1/4 turn and the compound slide has just a bit of movement. The amount I previously had when the screws were almost tightened. Tighten with 1/8 turn again and the play has disappeared but the slide still slides rather smooth. Also helped by the ball bearing mod I did last week. I now will let the surfaces wear in a bit and let it all settle and then I might see if I can get it even better.

I can take pictures if someone is interested.

[10KPete]

When machines are correctly made and fitted, life is wonderful!!

Pete

[mechman48]

When machines are correctly made and fitted, life is wonderful!!

Pete

I've had similar problems with my machine when I first got it; the undercut on the top slide was way too large & the gib strip was some piece of scrap steel. I got shot of the original gib & machined up a new brass strip... not a 100% perfect but much improved & more rigidity... tried post a couple of pics but get error 403 when I press 'post' & message... 'website declined to show this page'... ?

George.

[petertha]

This does not pertain to you gib adjustment screws, but suspect you might have similar clamping screws popular on Asian machines, so maybe an opportunity to improve while the machine is apart. When I installed DRO on my machines, it highlighted an irritating issue. When I tightened the lock screw to clamp the table in position, it invariably moved the slide off position a couple thou because of torque/friction imparted from bolt against the dovetail. So I made a little contact foot that matches dovetail angle & a bearing ball in between locktited on either/or. That solved the issue, pure axial force with no unwanted twist motion junk.