removing the chuck

[shaju]

I cant remove the chuck from my Lynx220Lm machine to put the collet holder. I removed the three cap screws on the face of the chuck and tried to remove it from the draw tube with the face spanner provided in the kit. But the draw tube got unscrewed from the other end. I managed to take the chuck out of the machine along with the draw tube. I cant take the draw tube out of the chuck. It seems to be screwed on to a bearing which is fitted in the chuck. I want to take the draw tube out of the chuck and use it with the collet holder.

[Geof]

It seems to be screwed on to a bearing which is fitted in the chuck.

I think most chucks are similar in design so all this should be applicable.

No, it is screwed into a rotating nut inside the chuck.

Look in the front of the chuck while someone is turning the draw tube and you should be able to see what is rotating; actually most chucks have a liner piece held on with three little screws at the front that you made need to remove.

What you can expect to see is a flange with two small notches opposite each other and you need a wrench to fit these notches. Many years ago such a wrench would have showed up with the machine but it is probably lost by now.

All you need to do is get a bit of round bar that just fits inside the chuck and machine the end so you have a 'key' across the fit the notches, kinda like a big screwdriver.

Now comes the fun part: It is impossible to hold this wrench into the slot by hand firmly enough to undo the nut even when every thing is on the machine and if you let it slip out too many times you round off the corners and are really screwed.

Tap the end of your wrench and use a long piece of threaded rod through the drawtube to hold the wrench in place; tighten the threaded rod until everything is firm then back off half a turn.

Grip the drawtube somehow, if you put it in a vise don't crush it, and start unscrewing the nut and as it loosens gradually back off the threaded rod to keep ahead of it.

Good luck.

[dcoupar]

When this happened to me in the past, I've used a strap wrench on the drawtube with great success.

[Geof]

Originally Posted by dcoupar When this happened to me in the past, I've used a strap wrench on the drawtube with great success.

Good picture, can I steal it.

[dcoupar]

Help yourself, Geof.