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Hi,
I have a Hare and Forbes HM-45 mill/drill and find myself swapping between the milling collet chuck and the drill chuck on a regular basis. Don’t have a pedestal drill yet.
Currently I am tapping the draw-bar (after I have given it a few turns) lightly with a hammer to release the morse 3 taper.
I don’t think this can be too good for the bearings etc. What is the method that should be used other than tapping to release the chucks?
Regards,
Jan
I know nothing about mill drills but my pedestal drill has a slot in the quill into which you insert a wedge shaped bit of steel that came with the drill. It rides against the top of the taper and a few taps of the hammer loosens the chuck.
As far as I know with the HM-45 that is how you get the MT out. Make sure you use either a soft faced mallet or a block of wood between the hammer and the draw-bar
That is the common way to remove them, at my mates factory they use a bit of solid copper that's about an 1" dia and roughly 4" or 5" long as the striker
On An instructional video I watched, the instructor uses a spanner to give it a tap (Bridgeport Mill).
Back the draw bar locking nut off half to a full turn and wack it with a copper hammer.Quote:
Originally Posted by jvdv
It's normal practice . The downward force is applied to the morse taper not the bearings.
Kev.
You were not specific about things, but are you using the drawbar with the drill chuck?
Unless you are doing very high load drilling, the drill chuck arbour should mount securely in the taper without a drawbar. Have done loads of 22mm holes through 12mm stainless with a 1.5 HP geared head drill at about 50RPM without loosing the arbour in the socket, plus 12 to 16mm with countersunk recesses. This machine was a 3MT without a tang on the top of the arbour. Could always rely on the downfeed pressere to keep the arbour in the socket. Remember that the chuck fits to the arbor with another taper that is only about 12mm long, and they rarely seperate.
Probably would still need to tap to release the arbour, with a 12mm brass drift down the drawbar cavity, but you would not be transfering the shock via the threads on the drawbar.
I can confirm that there is a slot in the quill and I have found the wedge shape piece of steel that can be used to release the taper for the drill chuck arbor. This arbor is one of the ones with a tang on the end and I don’t use the drawbar on it.
The milling chuck arbor is tang-less and therefore shorter compared to the arbor on the drill chuck. The existing wedge is therefore not suitable for releasing the morse taper after milling. I will continue using the tapping method.
Thanks for all the feedback.
OK, so I was half right. :)
There are several ways. If there is a wedge hole, use that. Otherwise, you can sometimes use a wedge (or screwdriver) between the spindle and the chuck body. Or there is the general method of wacking with a hammer, buffered by a piece of hard wood. For stuburn ones, I sometimes prop the drill body on a piece of wood.