--- In firstname.lastname@example.org
, "Carol & Jerry Jankura"
> Hi, Vlad:
> > I toyed with the idea of modifying the arbor so it could accept
> > anything that has a 3/4-16 thread, essentially making it into a cheap
> > mill, but the accuracy of Z-axis would be horrible - plus/minus
> > something like .2" and it is not rigid with respect to side-to-side
> > forces either. At least, that's what I found to be true with my
> > craftsman drillpress.
> A total accuracy of four hundred thousanths is almost half an inch.
> you make this determination? Or, perhaps, you meant only +/- twenty
> thousanths (0.02).
well, I meant +/- .1 - together making up .2
I really just eyed it, I didn't measure it with any instruments. There
are two things that contribute to the drill press being that loose -
one is that the bearing has plenty of lateral movement (you can move
it by a few hundredth by just applying hand pressure to the chuck in X
or Y direction), and also the column axis deviates from true vertical,
especially as you lower the chuck, making it a lot worse. But none of
that is really a problem if you just drill holes without applying any
side forces. I have seen better drill presses - this model seems
particular flimsy, and mine is especially bad.