With most keyed chucks, you can open up the jaws and put a drill bit in the lathe chuck to drill through the body of the chuck. There is a short cavity between the chuck and the end of the arbor. Then you can remove the arbor with a parallel punch. Your method of fitting the chuck to the arbor should work, just withdraw the jaws first to avoid damaging them.

A morse taper only needs a light tap to grip enough to drive the drill so I don’t think the taper in the chuck needs too much of a hit to grip firmly, fitting a MT shank drill I would either press down on a piece of wood using the quill or give the drill a light tap with the Barson drift. I usually have a small copper mallet handy now to give the drill a light tap. Once you have run some drills near the capacity of the chuck the drilling pressure will secure the chuck but obviously you initially need the chuck to grip well enough to not slip. It does not need a severe beating to grip well.

Mike

Look at it from the perspective of the designer. It's useful to make drill chucks that will fit any number of machines and useful for machines to take any tool. Ideally the answer should be simple, cheap, accurately resettable, and reliable. Tapers are a good solution because tapered plug-sockets provide a high-friction joint by wedging together, and it's easy to make adaptors that fit accurately along a radial axis.

Tapers are often used as a quick release mechanism. This variety needs to be tight enough to not slip, but loose enough to remove without drama. Over-tightening them is a serious sin, and being slapped in the face with a wet fish is inadequate punishment.

The other type, such as drill-chucks, are rarely removed from their arbours, perhaps never, so little harm done by fixing them firmly. An effective way to do this is to deep freeze the arbour whilst warming the chuck in an oven. Then quickly assemble the two and tap home once with a dead-blow hammer. The arbour expands on warming while the chuck contracts on cooling – the forces involved are enormous.

Firmly assembling a taper is declaring there's no intention to break the joint in future, which is usually fine. I suspect it's mostly amateurs who remove drill-chucks, either because they like repairing and re-using things, or are too careful with their money to buy two! Anyone making a living by cutting metal is less likely to waste time mending old tools or swapping arbours. Pairs of wedges are sold for removing drill-chucks, though I haven't seen any recently?

Drilling tends to tighten the taper, so no need for anything else unless a big drill does something unusual like widen an already big hole. (Lots of twist coupled with low down pressure.) Milling is different! It applies sideways forces and vibrations which tend to loosen the joint, so the taper has to be held firm with a drawbar.

My drill-chucks were all attached by plonking the chuck body head-down on a bench, pushing the cleaned arbour firmly into the cleaned chuck, and a single sharp tap on the arbour. None of them have ever come loose. I've only once needed to remove a drill chuck. It was after accidentally attaching a new one to the wrong arbour…

Dave

An additional method of getting a tight (Possibly non removeable ) fit would be to put the arbor into the freezer over night, and fit into the chuck while it is still cold.

A variation on the "Heat and Freeze" technique, that should get you an extra few tenths of interference once everything soaks back to ambient temperature.

HTH

Howard

Just the opposite! I acquired a second hand drill chuck which had an unwanted tang end of the MT2, as I really wanted to use in with the drawbar for drilling on the mill. It resisted my efforts to remove the taper. I settled for using it in the tailstock. Couldn't believe my luck one day, using it and chuck simply fell off it's taper! Immediately ordered a drawbar type from Arceuro, so it only now gets used on the mill. Maker; CVA, holds smaller drills than the Jacobs one now only used on the lathe. Mill is painted blue, so I painted a blue ring around the outer body of the CVA chuck and blue paint on the chuck key, so they don't get muddled up. Keys are not interchangeable.

Edited By DMB on 06/02/2022 21:48:54