Re: Acme Thread- opinions?

First, I wanted to thank everyone for the help.

Right now I'm building a small table using that XY milling table that
is on sale at Enco for $90. Got a recommendation from someone on
alt.machines.cnc that it only has a few thousands of backlash, and it
is mentioned in an article in Nuts & Volts magazine for conversion to
stepper drive.

For the Z axis I may just do as has been suggested and get a one-axis
drill press vise from Enco. The vises and XY tables at Harbor Freight
are just so darn sloppy. I was shocked, even their mills have really
sloppy leadscrews. Kinda ludicrous to have a vernier dial readable in
1000ths, and have it take 1/4 turn of the leadscrew to re-engage the
threads in the reverse direction.

I'm really interested in the Acme leadscrews for my next project, an
indeterminate time after I finish this one. This is going to sound
strange, I know, with you guys talking about 5 and 8 axis machines and
table tops less than 1000th off of flat... I have a large 3' x 6'
gov't surplus desk I'm thinking of using for a base. I won't be
machining spacecraft parts (I wish!) so I can tolerate less than
stellar accuracy. I will use it to cut signs and parts for props,
things like flying saucers and spaceship control panels. Whoops, I
guess I -will- be making spacecraft parts!

I have to check it to see just how level and stiff it -really- is. I'm
thinking I'll bolt a sheet of aluminum (1/2"?) to it and adjust the
feet of the desk to eliminate any twist. If they don't have locking
nuts now, I'll add them.

BTW, what -is- an "ANR Adjustable Compliant Nut"? Is that supposed to
be an Acme nut that can be tightened to limit backlash?

Happy New Millennium!

Steve Greenfield