Messages

1

General Mach Discussion / Re: Plasma Application, Mach3 torch height control.

« on: March 03, 2010, 12:58:16 AM »

Eureka!
$27, about 120+- hours of staring at code and about 2 dozen cappacuinos = DIY DTHC over USB.
My widget looks like robot guts but the torch goes up and down and makes really purdy cuts.
Runs in Mach via da Brains.....BRAINS!!
Almost have it setup in EMC for the Linux set. (Why are you reading this forum?)
Thanks to Matt for the inspiration.
I'm working up a how-to and eagle schematics but this is the blueprint.
Tip volts --> BRD --> Volt. Div. --> Trans.Volt Sup. --> Hi freq gap --> RC filter/conditioning -->
PLC(10 bit ADCx3 sample) --> Modbus encapsulation -->Modbus RTU -->brains...Brains... BRAINS!!= Zup and Zdown releative to Tip volts.
ArcOK and trigger relay are piggybacked as well.
Electrons are fun. BRAINS!!

2

General Mach Discussion / Re: Plasma Application, Mach3 torch height control.

« on: February 11, 2010, 12:07:30 PM »

Hi Stirling.
Thanks for the sketch.
On the analog side I was working of a variable resistance voltage divider coupled with an R/C setup. This way depending on what a given plasma puts out in tip volts can be adjusted to fit within the 0-5v window that Arduino requires. I'm also waiting for some parts (including a new LM331) to build a voltage suppressor as to hopefully not feed the Arduino more than it can handle,

What I've got to date is a smoothing sketch to average the analog inputs.
I've got a comparator sketch similar to yours to manipulate up/down function.
What I'm working on now is getting a tip volts reading to send into the MACH DRO (1036?) for adjustment purposes.
That part I'm having trouble with is getting arduino to split it's output into 2 serial channels. (SoftSerial is what I'm working with to do the split)
One for the 0-1023 up/down comparator function and the other for tip volts.
I've been playng with the modbus slave sketch to get the serial based tip volts to the DRO.

3

General Mach Discussion / Re: Plasma Application, Mach3 torch height control.

« on: February 10, 2010, 06:21:21 PM »

I have been experimenting with the LM331 and trying to get it to register in Mach.
I followed freedom2000's wiring schematic originally but think I missed something as I failed to get a frequency out.
I then built a v-to-f circuit ala National Semiconductors web page using 3.3v.
The output was in the neighborhood of 4khz if I remember.
Twisting the circuit pot would very the freq +/- 1khz. I did not very the input voltage as I just didn't go there yet.
I used the index input in ports and pins and was able to get a reading on the spindle speed calibration graph.
At this point I was fiddling with my breadboard wires and back fed voltage into a pin on the LM331 that I shouldn't have and poof! Trabajo no mas. I'm waiting no some replacements.

As an aside, I got an Arduino for Christmas and am trying to get it to work as a DTHC independent of Brains similar to the stand alone units.
Progress is slow as I'm new to C+. I've got most of the blocks down but am working on getting them to work together.