Stepper for Homier and other questions

Message: 18
Date: Mon, 14 Oct 2002 15:11:03 -0400
From: "Terry D Palmer" <tdp_130@...>
Subject: Stepper for Homier and other questions

I have recently joined this group, and have been following the discussions
and have a couple of questions that I'm sure this group can answer.

I'm thinking of trying to automate a Homier mini-mill. I am wondering what
is the "standard" stepper used to automate this mill and what might be a
good source for those motors ? I've seen the dicussion on feed rates, etc,
but assume that there are probably several Homiers already automated.

Also, what is typically done for the Z axis feed ? I have seen some mods
with an acme screw.

Is it necessary or wise to go to ball feeds on the X and Y axis (and Z) ?

[It may not be absolutely necessary, but it will save a lot of problems.]

I think my approach is to assemble the modules rather than buy a
pre-packaged kit. I have been looking at the Gecko drives. I am just
starting to look at ths software, Turbocnc, Dolphin, Vector, etc, etc. One
feature that I think would be nice is to be able to work from AutoCad
drawings. Certainly the price for Turbocnc ( $20 ?) would make it easy to
get started.

[There's TurboCNC ($20 controller shareware) and TurboCADCAM (an entirely
unrelated drawing and 2.5d G-code package which I sell for $450). I mention
it because the rest of the items on your list are CAD or CADCAM programs.
Other control programs, beside TurboCNC, are CNC Pro, Master5, DeskWin and
EMC. These just tell the computer how to execute G-code programs, but don't
let you produce drawings or models (like a CAD program) or G-code (like a
CAM program).]

I'm not sure if I have the whole picture. One of the above software
packages runs on the PC that outputs (parallel port ?) to the 3 Gecko's that
drive the steppers.

[Right- one of the control programs like TurboCNC. These replace the
proprietary controls and built-in computers (think Centroid, AllenBradley,
DeltaTau, Fadal) that used to be the only way to run machine tools. ]

A power supply runs the Gecko / Steppers. Is that all, or am I missing
something ?

Terry
Northwest PA

[There's a lot more assorted stuff you'll need to put a control box
together, but that's essentially the way it works. Depending on the step and
direction signals they get from the PC and the control system that's
running, the Geckos send power to the motors in a series of pulses, each
equivalent to some portion of a step, depending on how your system's
configured. At least that's how I understand it- and I'm sure there will be
someone to step in if I've got it wrong...]

Andrew Werby
www.computersculpture.com