Jammed collet holder.

[steamlaser]

Once again my Collet Chuck on my Chester Champion 20VS Mill has jammed. Last time I had to strip the whole Head assembly off, take it to to the club house and an experienced club member managed to release it.
I am hoping somehow to release it by some "sophisticated brutality"! (It is twisting on the taper ,but will not release. The draw bar is now appearing to be free of the collet holder thread and will not screw back in.)
My question is ,should one lightly oil the MT Taper before reinstalling it, or should both male and female surfaces be oil free and clean?
Any advice would be appreciated.

[92220]

Hi.

I wouldn't use oil on the tapered surfaces. It traps dirt and then the collets won't run true. You say you can't re-screw the draw bar. What size is it? I would guess either 3/8" (M10) or 1/2" (M12). If it happened to me, I would turn down the end of a piece of steel bar to easily slide into the thread bore in the chuck, and long enough to touch bottom of the tapping size hole. Then I would lock the spindle and whack the steel bar with a hammer. Don't forget to taper the end of the turned down steel rod sp that it doesn't splay out and lock itself into the tapping hole. If there is no bottom to the tapping hole you will have to use a bar that just goes down the drawbar hole in the spindle, and rest it on the end of the chuck taper. Again, make sure that if the end of the bar splays out, it can't lock into the drawbar hole in the spindle. Once you get it out, you can do what I did to remove my ER32 chuck. Make up a nut and very short bolt head which will just fit between the chuck and spindle end of the quill, so that you can prize them apart with 2 spanners.

If you PM me your email address, I will send you some photos of what I did.

Bob.

[steamlaser]

Success. I finally managed to extract the collet holder. We never had trouble at work extracting collet holders ,but they were not machines from the Far East.
Once again, many thanks for the good advice given.