My next little machine is going to be dubbed my "Black Magic" version.
It's going to aim for a bit more of a bulletproof assembly and use a few
things out of the ordinary.
As these little machines are all about smaller and more precise work, I have
a 3/8-16 brass screw that I'm going to use as the leadscrew. That has
a few advantages, I'm thinking.
One, there's little reason to use acme on a small machine that doesn't get
the extreme forces that acme was designed for. The brass is easy to polish
and will look good. The common tap needed can be purchased anywhere
for cheap...(acme taps are $$$$!)....which means an owner of the machine
is not dependent on someone else for the longevity of his machine. The user
made Delrin nut develops too much backlash....just make another in a few minutes.
Make different nuts on demand.
As the nuts are plastic, brass or steel would make no difference.
I'm thinking the common threads on the brass may even work a little better
than the acme, as there's no thread valley to shift on direction change....
should-be meaning, that it's easier to make a more backlash free nut.
But it's a wait & see. The finer pitch of the screw is another small plus....
assuming the point of it is to do finer work at the expense of high speed rapids.
There's a few other details to work into it, and I've already started on it.
Maybe a week or so to gather all the parts...along with the needed time to
do it all.
I think it's going to be a really nice little machine....
John