Purpose of cup on drawbar of PM-25

[Nyala]

I have owned a PM-25 for almost 2 years now and have been having a minor issue with the cup, whose purpose is seemingly to had in the drawbar. It keeps coming loose. (I think I over-tighten the drawbar because this always comes loose when I loosen the drawbar)

I just watched a video on YouTube where a poster built a new drawbar that had a bigger hex head for the wrench to tighten/loosen the drawbar. He removed the original cup and stated he would not be needing it anymore.

If he originally needed it, and now doesn't, why did replacing the drawbar with a hex head on it negate the use of the cup? Does the cup serve another purpose?

Thank you.

Denny

 

[jaek]

The cup is there to push the collet or whatever out of the taper in the spindle. Without it you need to back the drawbar out a couple turns and then whack the top with a hammer.

 

[Nyala]

Thanks. I get it now. The guy on YouTube will have to tap his drawbar to release the taper. He didn't specify that.

Thanks for the help.

 

[shooter123456]

It is for securing the quill return spring. From the PM-25 Manual:

"Do NOT try to lock the spindle using the flats on the drawbar cap; this is screwed onto the spindle to secure the return spring cup. "