Subject: nc mill
From: Rotary Engine
Date: 2/21/2006, 5:20 AM
To: AA-me


Paul,
 It looks like Jon from Pico contacted you. He works alot with EMC and

has a nice setup. Go to http://www.usdigital.com/products/e5/  look
over these to see if this may fit the bill, 500 count differental
encoder. This will replace the resolver. Another direct hookup is
www.camsoft.com, a little more pricey. I know you do not like Windows,

but the other option is www.artofcnc.ca  . You might check with the
guys on http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/ to see if there

is anyone close to you, this is the EMC group. Richard


www.camsoft.com There appears to be something wrong with this one.
Perhaps it is misspelled.

www.artofcnc.ca this one seems to be stepper only. It is not just
because I am not fond of Windows it is because Windows is not a real
time operating system while Linux RT is. You don't want Windows stopping
in the middle of circular interpolation and going off and doing
something else. Makes nasty marks in the part.

Paul Lamar ...No rotor no motor.


I converted a mini lathe to CNC and I bought the Mach 3 software from
Artofcnc. The software installs low level drivers that control the
parallel port hardware before Windows get ahold of it, and it works very
smooth once properly set up. You will have to disable some Windows stuff
like the automatic screensaver and sleep modes. You would want to use a
PC dedicated to the mill anyway so that should not be a problem. The
Mach3 software is free to try out to see if you like it.

A year ago, I converted a Cincinnati mill that had resolvers and SCR
motor controls. We had to replace the resolvers with encoders which
required machining some parts to adapt, but the encoders are cheap and
work excellent. We retained the Getty motor controller and used  a Rutex
drive to go between the PC parallel port and the Getty drive. It took a
while to get everything tuned up but finally got it working great. If I
wasn't so busy at work I would come help you Paul. It's a fun project,
almost as fun as building and flying a rotary.

Chuck Dunlap

I did not know you did this kind of stuff Chuck. You are
multi talented guy.

My resolvers are mounted on the back of the servos geared off the
servo shaft. Any tips for finding encoders that will fit?
Here are a couple of pictures. It would be easier if I could
find a resolver to count box.

BTW have you decided what you are going to do with your airplane?

Paul Lamar ...No rotor no motor.

Paul, I know your not to excited about Window's
products :-)  But as Chuck as noted the MACH
software has a very decent following,
and amazing results. The customer support is
second to none!  MACH 3 will drive either steppers
or servos. If your still skeptical of
its capabilities, there is a new version on the
way out as we speak, its been sent out for Betta
testing [you can download a free sample of it for
your own fun
and is to be usable by early summer. It's Called
MACH IV  and interfaces via TCP/Ethernet to the
drive Board from www.Geckodrive.com
called a G-REX G100. This drive board will drive
your servos at up to 4Mhz per axis! Are you
servos brushed or brush less? The G320/340
line of servo drives will drive brushed servos
and also interface back to the G100 with your
encoder for a complete closed loop system.

The G100 is totally independent from Window's
timing issues as it has its own dedicated on-board
processor.  This system is going
to be the cats meow as far as hobby level CNC is
concerned. If your servos are of the brush less
variety you can get similar drives
from www.Rutex.com  which will also interface w/
the G100 and also offer you the same closed loop
encoder feedback you desire.
Also as a side note the Mach3 [ and I expect Mach
IV will have it also in the near future] has an
add on to simplify short
and lower level NC programing, it will set up the
simple stuff for you for making regular shaped
item's. If your looking for heavier duty stuff you
can
get RhinoCAM which is a sister version of
VisualMill. This is the full blown CAM system
which will take your tooling and generate your
required code.

I'm going to be using some of this hardware myself
in my new Mill.

Hope this helps in some way!

Jarrett Johnson

Isn't the Gecko a stepper. 4Mhz sounds like a stepper.
My servos are analog. Pulse width for speed and and a bit
for direction.  I don't know whether they have brushes
or not. I don't think my servo amps care. There is no need
for anything other than the cheap PC processor mother board
with a real time operating system like Linux RT.

Furthermore my Windows computer crashes almost once a day
on average while the Linux runs 24 hours a day seven days a week
for years without crashing. It is always telling me I need
to notify Microsoft of the problem but I never do :)

I can just see it now :) I am near done with a mold taking
12 or more hours to machine and Windows crashes ruining the
part :) There is no beating having the source code out in the
open on an operating system.

There is lots of software out there that converts CAD program
software to NC codes and has been for years. Surfcam is one
of them.

Paul Lamar ...No rotor no motor.

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