Re: 5-axis machine controller

["Lawrence Glaister" <lg-at-jfm.bc.ca>]

Hi Robert,
I have a phase drive system running with EMC. The electronics package is
from TMG (The Motion Group) and is a small box with power supply and 3 2A
stepper drivers. In the cvs code, I wrote an alternate phase drive
subroutine that could be used to drive unipolar stepper phases through a
logic level fet and current limiting resistor. The code I wrote is very
simple and can be changed from 2 outputs/motor to 4 outputs/motor quite
easily. The output bit patterns are looked up in table. You could also used
a decoder driver chip to convert the 2 bits/phase to the 4 bits of logic
level fet drive you are considering. You may want to have a look at the code
in emcmot.c around line 3500. Let me know if you need some help modifying
the emc code. I am starting on a drive system for a new machine and need to
run 4 unipolar steppers at 4.7 amps/phase. I am still looking for the
easiest/cheapest way to get the job done. I have not decided if I will use
the direct phase drive method with resistors or try something that has a
switched mode current source for better efficiency.
=======================================================
Lawrence Glaister VE7IT             email: lg-at-jfm.bc.ca
1462 Madrona Drive                  http://jfm.bc.ca
Nanoose Bay BC Canada
V9P 9C9
=======================================================
----- Original Message -----
From: Robert <cncrouterusa-at-netscape.net>
To: Multiple recipients of list <emc-at-nist.gov>
Sent: Wednesday, December 20, 2000 2:01 PM
Subject: Re: 5-axis machine controller


>
> Marc and list,
> It sounds like you could do with the ZipEMC CDROM. I have it loaded on
with
> "another OS" dual booting. I had a few problems with basic video config
> getting X server started and setting the "run and ini" files up. I
succeeded
> in using the step/direction mode driving hacked floppy drives. I could
copy
> it and send it to you I think. I am waiting on spare $ to get drivers and
> motors to work some hardware with.
>
> I am a little cornfused as to some of the other responses about "phase
> driving with EMC. I was under the impression that there is a 2 bit phase
> output meant to drive a particular machine that had that type of driver.
> Matt wrote that it is not like MaxNC but Bridgeport. Maybe it will input
to
> your drivers. The starting message of the thread from Fred shows the
> connection(?) in ASII. The list archives
> http://www.nist.gov/itl/div896/emaildir/emc/maillist.html  a message or 2
> concerning this.
>
> I have a MaxNC driver board which is similar to what you want to do, 4700
> chips and NPN transistors driving small motors. I have used a program
called
> Turbo CNC that drives inputs to the MaxNC driver, but it requires 2 LPT
> cards to do 3 axis.
>
> Not being a true electronics person, I am wondering if I can drive floppy
> controllers, why can't I take the outputs to the motors off and send them
to
> amps to drive small motors or maybe even to the inputs of the MaxNC
driver.
> I don't know if this is helping any and request any clarification from
> others.
> Robert
>
>
>