It’s a drill – not a mill!

Drills are not designed for milling.  The quill bearings are designed for axial loading, not radial loads.  If it has an MT into the quill, don’t be surprised if it falls out.  Morse tapers require a drawbar to prevent this.

But carry on as you wish, if you must.  It will not affect me.

The chuck is only held in by friction on a drill press. As the milling cutter shears off the metal it will exert a pulling force downwards on the taper holding the chuck in the quill. It probably can’t go anywhere but could weaken the friction holding the chuck causing it to slip or cutting to stop.

Try waggling the chuck with it at the top, it will move quite a lot. Then bring it down a bit and try again. It will waggle a lot more. The quill is always a rather loose fit and not provided with adjustment on this type. One complicated way people have improved this a bit is to put the rack engagement pinion into an eccentric bush to take up the slack.

A drill is a drill

A mill is a mill

Horses for courses.

As my Dear Old Granny used to say .

BTW, I tried that many moons ago, best forgotten !

Hi, there is also a good chance that the table grip on the column will not hold the sideway forces of milling. The helix of milling cutters will also influence the chuck pulling out of the quill, without a drawbar.

Regards Nick.

I have tried using a drill for milling, it is possible but don’t expect too much. My advice is to use a proper milling machine.

My drill has a spindle with MT2 taper, and I mounted a cheap XY table on it. To prevent the cutter/chuck from moving/falling out I threaded the outside of the drill spindle and made a threaded nut to suit so I could use the Myford MT2 collets I already had. It worked using small size cutters and very light cuts, but a Mini Mill worked much better and gave much better results.

Thor

It is never good practice to try to use a drilling-machine as a mill.

I have got away with cutting a single, short slot that did not need be accurate in 3mm PVC sheet, but would not dream of making a habit of it, nor of attempting to use a drill for better-quality milling in metal. In that case the work was on a rotary-table for holes on pitch-circles, but also allowed careful feed for the curved slot.

The chuck and bearings are designed for axial loads only.

The quill and spindle are unlikely to accommodate a draw-bar but might on some machines.

A milling-cutter held in a drill-chuck is likely to slip and act like a self-tapping screw in the work-piece and whatever is directly below it. I have had that happen even on a proper mill, once where I’d not fully assembled the cutter into an ‘Autolock’ chuck, but also with an R8 collet.

The lack of a quill lock is more nuisance than real loss, but a wooden block between the top of the chuck and the underside of the head may hold the quill in place enough to assist setting up the work; or when using a spring-drive tapping-guide. These are the point of the quill lock on a drilling-machine. Not as a depth-control for milling.

You say you think in your opinion the return sprig is too strong. It is easy to change the tension. Just loosed off the two nuts on the silver cup opposite the quill handle so the cup can be moved to the left so the slots in it disengage from the tab on the casting (making sure you hold the cup or it will spin around), now rotate the cup to a new position where the tension is to your liking, and re-engage the slots with the tab. Once satisfied redo up the nuts.

John