Clarkson Autolock C chuck on Centec mill

Hi all, just getting everything assembled on my Centec 2A mill and have a few questions. Purchased mill complete with vertical head which included a Clarkson C type chuck (I believe) ie has the collets with two prongs, a sleeve inside the chuck and then the nut. Have found lots of instructions on use of the S type chuck but not the C type, can anyone help re securing cutters etc? Also the securing nut has the spanner flats on the "upper" edge so assume you must need an open ended spanner to secure the nut and not the ring spanner supplied? Any help appreciated, many thanks

No-one used a C type before?

John,

I have only used the S type, but ... a few seconds searching on Google located this thread from 2006, on another forum.

MichaelG.

Hi, yes I had seen that post but doesn't go into the nitty gritty of tightening up? It seemed that the S type needed a particular method so was wondering if there was anything special on the C type or just give it a go! Cheers

John - my Centec came with a Clarkson Autolock chuck - but after close to 20 years of owning the mill, and never using the Clarkson chuck, I gave it away, and use ER 25 collets almost exclusively. ("over here" at least, the screwed shank end mills are very hard to find and pricey, and I try and do everything in metric, so the autolock chuck was of no use to me)

Sorry, no help I'm afraid!

Another John.

My Centec 2B came with a Clarkson chuck that, I also have never used. I got an ER32 set from RDG and have had no problems.It grips anything in its range from 2 to 20mm.

I used these older Clarkson chucks during my apprenticeship (1958/1964),procedure was as follows and everyone in the factory worked this way, slip the collet in the sleeve,push sleeve and collet into the chuck body ,screw cutter into the collet until the the screwing action starts to push the sleeve out of the body,the sleeve should move by about 1/32 on an inch,then screw the nut on by hand.do not use spanner. everyone was warned to let the sleeve move out a little and do not use a spanner or will be a b------ to remove the cutter,these instructions are not the same as the later auto locks and thats where the confusion and disagreements started over how to use the later types. The modern ER collets are good I have some to hold taps in the tailstock,but a ER will slip if pushed too hard particularly on the bottom end of the 1 mm range,,a Threaded Clarkson will not pull out or slip,essential when machining say a keyway in tough material,and the keyway must have constant depth.

Cheers that's great thank you, will give it a go tomorrow

I've heard this concern from others, but I've personally never had an ER slip.