Re: [CAD_CAM_EDM_DRO] running the BDI EMC on a real machine

Hello, David!

It is good to hear a few people (a VERY few) have EMC up
and running with full servo drive being calculated by the software.

I am going to spend the money for a card and see what happens. Any
accountant I think would say to go with a
commercial control for $5000+ and start making chips.
I guess I just like the open source concept. I may be even
a little irrational in choosing this.The cost of the card is not as much as
issue as the engineering time to debug the system. We will see what happens.

In any case I will document what I do and try to put it up
on a web site. This will be specifically using STGII and the
latest BDI with servo calculations done by EMC. If it works
it promises to be a pretty high performance control system.
I am hoping that the PID /feedforward algorithm is functional-
this means true 4 quadrant operation with realizable multi-pole
integrators and differentiators. If they are not, I think I could write the
code to make it so.

I also hope the New Mexico real time Linux kernel is stable
enough to not constantly crash.

I think I should post the details mostly on the NIST list rather
than here unless anyone thinks it should be here.

On another note, looking through your web site made me think
of a movie I saw on A&E yesterday. It was called "Longitude".
I particularly liked the clock flywheel (?) made of copper and iron to
cancel the effect of thermal expansion by using dissimilar materials. What
elegant mechanical computers!

Merry Christmas!

Les

Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.rabun.net/~leswatts/wattsfurniturewp.html

----- Original Message -----
From: "David M. Munro" <munro@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Monday, December 24, 2001 5:11 PM
Subject: Re: [CAD_CAM_EDM_DRO] running the BDI EMC on a real machine


> Hi, Les,
>
> I have EMC running a series I Bridgeport CNC, a retrofit from one to the
> later BOSS controls, by Matt Shaver. It has a STG card running four
> axes through new drivers, but the three original motors. I'd be less
> than truthful to say that it is much more than a work in progress, but I
> have made a fairly complex metal part, and am working hard to understand
> the intricacys of the process.
>
> For some pics see this page, and follow the links to see more:
>
> http://www.arcadianclock.com/workshop/cnc/
>
> We are a long time from "EMC drives servos for dummies". I paid to have
> a lot of the hard stuff done and there have been times when I've been
> close to banging my head on the machine in frustration. There are lots
> of very complex things that have to work together, and when they do,
> it's quite amazing to see.
>
> David M. Munro
>