chipmaster gibbs adjusting

Hi guys,at work i have access to a colchester chipmaster which has play in the cross&tool slide, i have tried adjusting both, but the cap heads screw into the gibbs making it unadjustable as the holes for the capheads are not elongated, am i looking at this wrong???? any help appreciated.

Thanks Garry.

Hi
The cap heads may be bottoming on the shoulder. . Or you could turn the heads down a. the c/bores dont need elongateing
Nobby

Is the gib so worn that you need excessive movement beyond the "slop" in the cap head holes/counterbores when you tighten the grub screws?

Thanks for the replys, i think the gibs may be worn to excess, i thought there might have been elongated screw &caphead holes as there doesnt seem to be much adjustment at all, do you think it would be safe to open out the drillings? this machine is old & the company wont pay out for repairs so i would like to try and get most of the play ou,t mainly for my own use at work.

The Chipmaster pictures on lathes.co.uk have grub screws (not cap screws) for gib adjustment. How MUCH play ? has someone nicked the gibs and fitted long cap screws? If the gibs are there then you might be able to move them along as the grubs go into depressions in the gibs or fit longer screws. That would need a fantastic amount of wear to take BOTH gibs down that much- don't sound likely.

Billy.

Edited By Billy Mills on 20/12/2012 10:50:56

Hi Again
Why not use longer screws , so the heads dont bottom . or grub screws .A photo may help us see the problem better
Nobby

Billy's right use grub screws . He beat me by 1 second
Nobby

Hi Garry,

Have you taken the cap head screws out and looked in the scrw holes? Someone may have put the cap heads in to lock grub screws in position. Just a thought.

Peter.

Good thinking Peter
Nobby

Hi guys,lokking at the cross feed gib it is held in position by capheads from the top and the gib is threaded to accept the caphead that locks it into position& the side grub adjusters have no locking screws on top of them, the tool slide has the capheads opposite way round the gib is counterbored and slide is threaded, my guess is ive run out of adjustment. any options i could take? trying to ad some piccys**LINK**

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Hope this one works.

Thanks Garrygun, that is what I suggested.

Hi Guys
A picture / photo is better than a hundred words .

Nobby

Should the (grub) screws have nuts on them to lock them? I thought that was the normal method, I wonder if cap head screws were put in at some stage, so that a larger Allen key could be used. Ian S C

It is a common practice on some makes to use two grub screws per hole, one to lock the other Bit more of a fiddle to set up because the locking screw takes out the backlash of the first screw.

Hi Ian,
From the links to the pictures of the gib on Garry's lathe it looks like it is totally different to the normal gib strip which is about 4 mm thick. The gib on Garry's lathe is solid piece of metal which is held in place by cap screws. Once the grub screws have been used to adjust the gib and the cap screws tightened it does not matter if the grub screws move. I have not seen this arrangement before. As Nobby says "A picture / photo is better than a hundred words"

Les.

Les, not seen this arrangement before? Look at a Myford Super 7

Hi Guys & Kwil
On my super seven the cap screws are on top of x slide adjustment is on the side using 2ba grub screws . On the Exe lathe I am working on has square locking nuts as Ian mentioned. Drifting away from original thread sorry
Nobby

Take out the gib strips and epoxy shims on the worn sides. Blue the shims and the dovetails so that when re-fitted you can see where the wear is.

Billy.