Run-out on face of 4-jaw

I don't know if it will help, but the clearest intructions I have seen for Camlock fitting are on page 2 of this.

In my limited experience; the less than 0.004" starting-point is crucial.

MichaelG.

Even if you don't skim the back it would be interesting to see what the clock says when run against the back, make sure the faceplate is spot on first.

I did skim the back and register of my 5C chuck.

I had a similar problem with a couple of D1-5 Camlok baclplates before, It turned out that the taper in the backplate was "out ". The taper was correct but not of the correct dia [ too small ] so I set everything them up on the face plate and got the correct angle for the taper and had to take off 0.09 mm They were both the same so at least the error was consistent !! They now locate perfectly on the spindle nose. The tight taper was causing them to rock on the spindle nose, and you could tighten any one of the 6 camloks and that would cause the chuck face to deviate away from the spindle axis because it was not getting pulled fully up to the face of the spindle, with the result that any bar would not be held straight. I now only ever use Rohm ones, and no more having to machine the tapers. The Camlok system is great, but the tapers MUST be spot on or all bets are off.

The backplate sans chuck runs true..or at least within 0.005mm. Ive had it on there on it's own again today.

Last night I left things with an awful runout and 3 thicknesses of ally foil at the low point. Today i found that really leaning on the allen key bolts to backplate with a pipe extension and it then ran within 0.04mm again.

I upped to 4 thicknesses..no change apart from the low point moving 90 degs. mic-ing the 4 thicknesses they measured 0.04mm. I went to 6 thicknesses and the runout again went all over the shop even with the bolts seriously dogged down. At 5 thicknesses the runout is just over 0.02mm.

I/m still not seeing any marks on my blue but guts tell me it's the way it gets canted in the register when shimmed - well it's the only guess I have.

A quick eyeball suggests that it wouldn't bolt to my faceplate - the slots aren't close enough to the centre to match the chuck bolts and creating an accurate conversion plate is a pain. Inspiration suggest that the chuck backplate itself can be used if i skim and true up the face of the register and just reverse the chuck onto that since that's where the bolts go.

I think that for the moment I'm going to accept the 0.02 over the 200mm and go back to my project.. squaring a 4 in ally bar. If I can get that within 0.01mm I'd be happy.. I could probably do better on the mill but just not getting the finish I want there.

3 days of pratting with this chuck and I need a break from it

First time I've had some shed time for a while and decided i should grow a pair..

So with the rest of the faceplate showing 0.005mm I faced the register, mounted the chuck backwards and indicated the same 0.04mm to 0.05mm runout as the other way around and skimmed the back of the chuck. It now indicates 0.015'ish mm (or about 6/10ths of a thou). Possibly if I pratted around trying bolt hole mount options I might find sl better and doubtless with greater courage and facing the mount surface and the register surface in one session it would have been even better.

I think that puts this thread to bed.

> I think that puts this thread to bed.

There you have it - the official procedure is 'hit it with a babbit hammer until it runs true'.

Neil

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That's for the Type L fixing, not the Camlock

MichaelG.