Mini lathe cross slide gib

[quantumeer]

I have had the mini lathe for some years (Warco/RealBull). Its cross slide gib arangements have never been very comfortable: either too stiff or a bit wobbly, and the tailstock (gib) side can lift under load.  Careful examination against the light shows the problem:



It seems to me that the screws can't be placed low enough to press the strip properly against the underside of the dovetail, or for the strip to wedge instead of rotate when the screws try to lift.  I am at a bit of a loss as to how to fix this. Has anyone dealt with this before?  The dovetail height is 6mm.

Mark

[jim]

thats an eye opener!

Its never occurred to me check like that!

i cured my woes with gib strips by adding extra screws/lock nuts. i think that if you just put extra screws in, a little lower, it should sort out your problem

[John Swift]

Hi quantumeer ,

I took the easy way out with a machinemart / clarke CL300M lathe

(its a seig C2 but the gibs are the same on the C3 version)

I fitted the gibs that Arc Euro Trade sell  :-

http://www.arceurotrade.co.uk/Catalogue/Machine-Spares/C3-Mini-Lathe-Spares

they are a lot better than the original scrap metal ones

 John

[ketanswali]

Some of this is covered in our prep.guide which is to be found here:
http://www.arceurotrade.co.uk/Catalogue/Machines-Accessories/Lathes/Model-C3-Mini-Lathe/Model-C3-Mini-Lathe
see page 14 to first modify the gib screws, then re-drill and tap new holes a little lower, which could help.

[quantumeer]

Thank you for the comments, which put me on the right track.  My screws were roughly pointed, so I improved the finish on the point.  The original gibs weren't entirely scrap metal, but the indentations for the screws were certainly in that category, so I made wider, deeper indentations, with conical bottoms. Wanting the tightening of the screws to push the strip up into the dovetail, I made the cone angle of the indentations a bit wider than that of the screws, and located them carefully.  The result was quite pleasing:



The strip seems to be making full contact with all the dovetail (as much as remains after the manufacturer's rather enthusiastic corner relief) while the other faces of the strip don't interfere with the slide-saddle contact (that's a blob of oil at the top).  It's more secure than it looks, and withstands vertical forces a lot better than before.  Thanks, all.

Mark