Re: Linux vs. DOS

> -----Original Message-----
> From: Matt Shaver [mailto:mshaver@...]
> Sent: Monday, May 31, 1999 6:33 PM
> To: CAD_CAM_EDM_DRO@onelist.com
> Subject: Re: [CAD_CAM_EDM_DRO] Linux vs. DOS
>
>
> From: "Matt Shaver" <mshaver@...>

--snip--

> To be honest, you are the first person to control a stepper machine
> with the EMC.

I don't know whether to be excited or to run for cover <g>

> Fred Proctor has a little test stand that consists of a stepper motor
> driver box from Microkinetics with three little, probably size 15, stepper
> motors stuck to the lid of the box with double sided tape. You
> are the only
> one that has stepper motors coupled to a mill. All the other installations
> are servo motors. Congratulations.

All I can say is I am glad the kill button wired in with the limit switches
is working fine!!

>I guess there are a lot of unanswered
> questions that will come up like:
>
> 1. With no feedback (encoders) what do P, I, D, and a bunch of other
> parameters in the .ini file mean?

Guess with these when you know I will then understand what they are. It just
so happens that I do have encoders on my motors. They are 200 step per
revolution units and right now are not used at all. If there is any way to
run the steppers with feedback provided from the encoders it would make for
a pretty sweet setup. It would give the low cost setup of steppers and the
closed loop positional guarantee of servos.

> 2. We'll need to change the incremental jog menu items to match your step
> size.

Not quite sure what you mean here, but I definitely need to change the
setting to take my step size in account as it is way off.

> 3. Since in the servo systems we use a parallel port for spindle and
> coolant control along with estop, lube oil level sensing, etc. will we be
> able to add another port to your machine for these functions? What kind of
> mill is it? What controller, if any, were you using before?

Everything is home shop stuff. the controller is one of Dan's 5 amp choppers
and the mill is a Shoptask 3 in 1. Out of the list of extra functions the
only thing I may ever have a use for is the coolant control and that is only
if I ever get around to putting a solenoid valve in the air line to my mist
coolant unit. I would not have a problem putting a 2nd parallel port in if
it is needed, but with my basic setup I don't see the need.

> I'll talk to you later, and in the mean time you might want to look around
> and find your soldering iron.

Well, being impatient I sacrificed a spare parallel cable and now have a
cross wired cable that handles this small problem.

The correct axis's now move and I can make all 3 of them go. Whoopee!!
The only problem is one of the axis's moves in the wrong direction. Guess I
need to know how to configure the direction. Another problem is that the
physical movement is much larger than the amount entered in the controller.
My X and Y settings are 4000 steps per inch and my Z setting is 5600 per
inch. Another parameter I need to learn to set.

I even tried loading up some G-code programs and while I got noise and
movement and all the axis's made some motion I did have a number of
problems.

The default fast move (G00) speed is WAY too fast for my poor steppers. They
just make a terrible groan trying to rotate at that speed. Again, another
thing I need to learn how to configure.

When the program hit a line with a G42 cutter comp entry I got the error
message "convert_cutter_compensation_on error 43 blah, blah, blah"(OK, I
didn't write it down). This is even with a line in the program to specify
the tool (T1).

I am mighty confused about how to step through a program as the step
function only seems to work once you press run and then pause. Any idea how
I step into a program instead of having to panic and click pause before 4
lines have processed?

Major problem. If I only move the X or Y axis all is fine. If I move the Z
axis I start to get random very ragged movement in the X axis and any
movements issued for the X axis are interpreted incorrectly while this
random movement is occurring. If I make some more movements on the Z axis
the X axis movement problem will randomly go away and then return.

I look forward to getting this all worked out and actually making some chips
with this setup.

Again, thanks.
Tim
[Denver, CO]