Dumb question on R8 (i think) spindle

[r-mm]

My enco knee mill has what i am fairly sure is an R8 spindle however it has no keyway nor can I find any other means of preventing the drawbar from rotating the collet.

Am I missing something? R8 collets fit snuggly.

 

[Jim F]

Can you feel inside where a pin or key may have been sheared ?

 

[Ulma Doctor]

often the key is worn on well used machines and may not be pronounced.
my BP key is in bad shape, but the taper is good.
i have no problems with collets rotating

 

[Shootymacshootface]

There should have been a key at some point. I know that there are plenty of mills in use that the key has been sheared off.

 

[r-mm]

I did my best to feel all around inside and could find no key/pin or evidence of one previously having lived in there.

A friend pointed me to many threads with people saying they prefer R8 with no key. Is there a trick to getting the drawbar to tighten and not spin the collet/spindle?

 

[middle.road]

and mine is sheared off also...
Make sure it is very clean and then I just push mine up until it 'takes', then it tightens.

 

[Shootymacshootface]

I did my best to feel all around inside and could find no key/pin or evidence of one previously having lived in there.

A friend pointed me to many threads with people saying they prefer R8 with no key. Is there a trick to getting the drawbar to tighten and not spin the collet/spindle?

You need to use the brake while tightening the collet. Make sure the threads work together with zero effort, and there is no oil in the taper or on the collet.

 

[r-mm]

Another dumb question... does every mill have a brake? I can't find one on my Enco 100-5200 which is similar to Grizzley G0731. I don't see a brake in the manual for that mill.

 

[vecair]

My enco knee mill has what i am fairly sure is an R8 spindle however it has no keyway nor can I find any other means of preventing the drawbar from rotating the collet.

Am I missing something? R8 collets fit snuggly. View attachment 345873
View attachment 345874

Pull out your drawbar and make sure it threads into your collets without binding up. If it binds the collet will spin. Might have to be die chased to clean up the threads. A bid of grease on the threads helps as well.

 

[cathead]

The key on my Enco knee mill went away years ago all by itself. I use a little oil on the threads occasionally
and have not ever noticed slippage.