3MT Collet Questions

[Smudgemo]

I’d like to ask a few collet-centric questions, if I could. I've got an Atlas 12x36 w/ MT3 spindle. I made my own drawbar and normally hand-tighten it. The aftermarket options I’ve seen appear to include a spanner wrench to help tighten things. First, how do I know how tight to turn the drawbar so the collet doesn’t slip, but I don’t damage anything? I can drill the handwheel and use a spanner wrench I have for my mill if advisable.

Secondly, what type of hammer would be considered most appropriate to tap them out? My drawbar is turned from drill rod. My brass hammer is too small, and a ball-peen or claw seems inappropriate due to both surfaces being fairly hard. Big-ass brass hammer? Dead-blow? Preferably something I can grab at the local ACE.

Thanks,
Ryan

 

[wa5cab]

Ryan,

Assuming you have a handwheel on your drawbar that is about the same diameter as the factory one, just tighten it with with your left hand on the handwheel (assuming that you are right handed). You do NOT need a spanner wrench or both hands. The spanner wrench you might have seen in photographs of some commercial sets is for removing the spindle thread protector (which I sincerely hope that you have one of). If you don't, thoroughly clean and oil the spindle threads and put the chuck back on until you get one.

I use a piece of oak 2x4 about 6" long, not a hammer, to free the collet. Hold it so that it hits the handwheel squarely. And hold the cutter with your right hand while you are hitting the handwheel with your left.

Robert D.

 

[Smudgemo]

Glad I asked. Thanks, Robert.
I do have the thread protector, but never needed any tools to remove it. I haven't used collets much, but I just got a stub arbor with a MT3 taper that I'll probably be using fairly often and I'd prefer not to wreck anything.
-Ryan

 

[wa5cab]

OK. I like using collets for small parts. It takes some time to remove the 3-jaw but working close to the collet is less intimidating with the machine cranked up to several hundred RPM. ) I assume that you know not to use the 3-jaw to hold hardened cutters if you have any other way to do it. And as a practical matter, if using the milling attachment, workpiece visibility is much better without the chuck in the way.

Robert D.