Drawbar confusion

[Jim CParticipant @jimc]

Hi All,

I think I may have a self ejecting drawbar on my Rishton vertical mill but am confused as to its operation. It's design consists of a screwed collar that screws onto the top of the spindle and of course the usual drawbar with top nut. So was wondering if someone could enlighten me as to its operation if indeed it is what I think it is ???? Many thanks in anticipation.

Jim.

[Jim CParticipant @jimc]

Confused re operation of possible self ejecting drawbar.

[Steve FParticipant @stevef]

Hi

I have a similar design of self eject drawbar on my Warco mill.

Undo the drawbar and keep going. Eventually the drawbar will be far enough out and contact the collar. From then on the collar retains the drawbar and pushes the tooling out the spindle. Helps to be ready to catch the tool.

If you need to remove the drawbar at any time you first need to remove the collar.

regards

Steve

[Jim CParticipant @jimc]

Hi Steve,

Thanks for taking the time to reply. I think my machine is slightly different to yours but cheers for the advise. I have now sorted the problem by making a push bar which is acted on by the threaded collar to break the morse taper lock.

[JonParticipant @jon]

Like this one?

[Jim CParticipant @jimc]

Morning Jon, that's exactly my machine. The one in the photo shows a hex top to the drawbar, only difference is that mine is domed. The domed nut on mine does not pass through the knurled collar (obviously !!) so I made a separate pushrod which has a top that does fit inside the knurled nut and it pushes out the morse taper when the knurled nut is wound down. Phew !! Hop you get that description. Thanks Jim.

[JonParticipant @jon]

Can only suggest take it apart and have a look.
Could be a few things may well be to take excess length out of an overly long draw bar ie adjustable.

For an ejector you would want a hex with spanner, dome is to knock the draw bar out or loose when slackened 1/2 a rev. Or a slide hammer.

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