Re: Replacing Anilam Controller with EMC? / Another Choice

Hi,

I'm also converting a Bridgeport Mill that had an Anilam Crusader II
control. I've tried LinUx Redhat 5.2 with EMC but, I'm a bit
challenged on the PC side of a CNC system so. I went with Mach2 since
I've used it with a stepper driven router table. The machine has
Westamp style servo amps (+/-10v). I bought three Rutex 997's (they
have a newer and better version out now) step/direction to +/-10v to
interface the amps to the PC. The motors are SEM's 30Amp on X & Y
with a 20Amp motor on the Z. The linear encoders on X & Y pulse
every .0005" so, with a little backlash from the motors to the table
the motors will never be quiet and nasty things happen. I had to
mount rotary encoders on the motors. There's a 2:3 timing belt
reduction from Ballscrew to Motor. I've tried the encoders on the
screw but, I've found the motors quiet down with just a little
pressure pressed on the belt with that configuration. I think the
more ridgid the coupling of the encoder to the motor, the more the
motor will settle. The linear encoders are most accurate but there's
really is no deadband. The D/A conversion has to have at least a
little error bouncing back and forth to hold position. I don't want
to replace ballscrews so I'll live with .0005" or so of backlash.

So far, I have the X axis motor strapped to the table (not belted to
the screw) so I can tune the servo. That's another reason I like the
encoder on the motor rather than the screw. When the screw turns my
table moves and I need to have a fast hand for the kill switch.

The motor is nice and quiet and responds well to step and direction
commands. I mounted a 200 CPR, $15 ebayed encoder to the motor. 800
steps rotates the shaft one complete turn. Rutex has free software
for download to help tune your servos to their products. The software
interfaces thru the LPT port and will plot nice graphs produced from
data between commanded position to actual position. (It's easy)

Well, that's the path I took. I still want to try a Linux/EMC system
and is on the todo list. I guess another reason I didn't go with EMC
is at that time, the servo board to go with EMC was 8 or 9 hundred
bucks. (Is there a cheaper solution now??) The little rutex cards are
currently $88 untill 1/04. That's per axis. And yet another reason, I
use one notebook and just plug it into different machines. (I squeeze
the nickle till the buffalo)

Thanks for letting me ramble,

Jim Montgomery
SW Missouri









--- In CAD_CAM_EDM_DRO@yahoogroups.com, "another_roger"
<another_roger@y...> wrote:

>
> I have a Bridgeport with an Anilam Crusader II controller and am
> interested in replacing it with a PC based control.
>
> It has servos with tachometer feedback and drives so that a +/- 10V
> signal controls the velocity and direction of the servo motor. For
> position feedback, it uses linear encoders mounted directly to the
> axis.
>
> What I think I need is a PC, a STG2 card, and connectors to

interface

> the existing drives & encoders to the STG board. The main thing I
> need is enough confidence that I'll be able to get EMC configured

and

> running to spend ~$1000+ for this upgrade.
>
> Has anyone here set up a similar system? How difficult will it be

to

> get the software configured properly? (I have done small programs

in

> many different computer languages and have the electrical
> capabilities necessary, I'm just not very experienced with Linux.)
>
> Thanks!