I think I need a dust shoe. At the moment I'm prototyping so I hold the vac nozzle for the 10min that the job takes. But if I'm goingto run a 1hour production job then I need something to suck the swarf out of the work.

I'm using acetal down to a depth of 20mm, and the swarf builds up in the hole, I suspect it would clog up a bit and spoil the finish if left. On the other hand I might be able to rough everything out without suction, and then just attend with the vac to the finishing passes. So much to learn/try!

With 20mm travel do you think attaching to the spindle will work OK? I was thinking the dust shoe would have to be fixed height.