3/4" Capacity Drill Chuck: Lathe or Mill?

[darkzero]

Just out of personal preference, I would get an arbor to fit the lathe. Most of the time, you will have a collet to fit your mill that has a large diameter cutter, but for a lathe, if you want to drill a large hole with a drill....1/2" is about the standard. The larger you can get for the lathe the better. You may still have to turn down the shank some, but it would be nice to put in a 3/4" drill into a lathe without having to modify the drill. In a mill, you can easily use a 3/4" collet to put a drill in. Plus depending on what you are making in a lathe, if it takes a large hole, the larger you can start out with the better before switching over to a boring bar. If you can pop in a 3/4" hole in a lathe, you can start out with a large beefy boring bar to start out with, without having to work your way up. My vote is for getting a lathe arbor

Although I was leaning towards the lathe, I decided to go with the mill & I already got the R8 arbor for it. Thanks for all the suggestions. All my drills currently over 1/2" are S&D drills which have reduced shanks (1/2"). My current largest is 1" but a few larger is on my list. I can't go too large as the slowest speed on my lathe is 60 RPM which is not good for some of the materials I drill. The only straight size shank drill I have is 15.5mm but I turned it down to a 1/2" shank. But I got a 5/8" capacity drill chuck when I got my current lathe so that would have fit anyway.

Use of non-fractional reamers if ever needed is why I choose to go with the mill. And I could always move a part from the lathe to the mill to use it, not so much the other way. I had asked what other reasons for using a larger drill chuck on the lathe were but no one suggested anything. So I just went with the mill.

I'd put it on the mill, large drills in a lathe you really want a taper shank. You won't find many R8 taper shank drills!

Exactly my thought, some taper shank drills are what I have on my list to buy so unless I run into another reason. I hate when the drill chuck falls off the arbor taper when using larger drills (well not often, only happened to me once ) I think the larger drill chuck will be more useful on the mill for me.