I tend to lock the quill and lower the head, may use the quill for initial cuts but last few are done with the head. Less extension of the quill = more rigid setup and hopefully a less tapered hole.

Edited By JasonB on 24/07/2023 07:17:45

If using the quill to downfeed you need to make sure it is descending in a true vertical plane, otherwise the hole will be bored at an angle to the top face.

Emgee

You are not out of step Andrew you just don't have a benchtop mill like the OP (RF45 clone) and I do where the head moves rather than the knee. You also have powered feed to the quill so have the option to use that that the OP does not.

You do also raise an interesting point about quill travel, which is another reason moving the head on the benchtop mills can be of benafit as that often exceeds quill travel. If that fails there is always the option to use the lathe as a horizontal borer for those that don't have a dedicated machine with the bonus of the lathe having powered feed.

Though both our CNC machines move the head when boring.

I had a problem recently with a bore being slightly tapered when using the quill of the round column mill. It has 5" of movement and very little wear, but still the taper was a nuisance. The Tom Senior light vertical has only 2 1/2" of quill travel, but also has a knee which makes up for that. I posted a thread on the subject earlier this year. You can use either depending on the hole depth, but if using the quill, have the clamp slightly done up to tighten up the movement somewhat.