Re: [CAD_CAM_EDM_DRO] Hi :)

bigshrek2005 wrote:

> Total newb here...I'm about to embark on making small parts and I'm
> trying to figure out the least expensive way to do it...but do it well.
>
> Most parts will be no larger than 2"x3"x1", made of hardened aluminium,
> so I guess a basic mini-CNC-robot or CNC-mill will be the way to go.
>
> The parts will be flat on two sides...many with a cut 3/8" groove on
> the bottom side.
>
> So what should I start with?
>
>

Well, your part sizes indicate a Taig or minimill like an X2 should
work. I have a
minimill that I bought because it was light enough to lug to shows, but
I normally use
a Bridgeport. But, i have done some test cuts with the minimill and it
really isn't
that bad. I originally put steppers on it, but then upgraded it to
servo motors. it is
what I use for all sorts of testing projects.

Anyway, either the Taig or minimill has a vertical column with slideways
on it, so the
head doesn't swing when elevated. The "mill drills" mostly have round
columns, so
you lose your XY alignment anytime you elevate the head - a major pain!

For serious machining, the Sherline is a bit light for my liking. The
CNC-ready Taig
has a motor set up for higher spindle speeds, a definite advantage. The
minimill has
a rack and pinion Z axis, which needs to be replaced with some kind of
leadscrew
(either Acme or ballscrew) for any precise work. Also, the Y axis
leadscrew bracket
has just a brass bushing, I machined this part to put two ball bearings
in it as the thrust
bearing, it works MUCH better now.

See http://pico-systems.com/minimill.html
for more info and pics of the mods I made to that machine.

Jon