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Author Topic: galil thc  (Read 8852 times)

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galil thc
« on: June 29, 2009, 10:51:29 PM »
Has anybody tried to write code for the galil controller to use the analog input for torch height control without going through mach3. It appears that mach has to slow an update rate 10hz or is there away to get mach to look at this faster.

Offline smurph

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Re: galil thc
« Reply #1 on: July 01, 2009, 06:39:10 PM »
It will have to be done on the Galil.  I'm not real familiar with the concept of THC, so if you will explain what needs to be done, I'll put it in the plugin.

Things like do you need to configure a max movement range.  And what happens at +10v and -10v.  +10 is Z riased and -10 is Z0?  Stuff like that.

Steve
Re: galil thc
« Reply #2 on: July 01, 2009, 08:42:54 PM »
If you look at the experimental thc plugin written by Brian Barker it has everything needed. But it has to be done in the galil for the fast update. It should only work when the torch is in motion.
Re: galil thc
« Reply #3 on: January 05, 2010, 07:48:42 PM »
has anyone got this right on the galil yet? if so can you share your code
if its not broken yet, fit more gadgets!

Offline kcrouch

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Re: galil thc
« Reply #4 on: January 05, 2010, 09:17:41 PM »
You can help us by giving details of what you want it to do and how you want it to work electrically. I know nothing about plasma cutting, but can make the plugin better with your help. Please e-mail me with some information so that I can get working on it. Thanks,
Kenny
Having way too much fun! Something must surely be wrong.
Re: galil thc
« Reply #5 on: January 06, 2010, 06:46:14 AM »

http://www.candcnc.com/
see dthc section

basically it requires an analogue input to read from a voltage divider circuit ( 0-400v dc at torch cathode output divided down to give 0-10 v at galil input)
the operator sets initial pierce height (variable for different material/thickness etc) above the metal which is higher than the cut height, also a variable parameter set by the operator for material to be cut.

the plasma should have a floating head with height rference switch  touch off on it. ( z reference lowers the torch, in switched off condition to metal . the torch continues down until it activates the the z reference switch fitted to the floating head. at this point the z is raised by the travel of floating head to z ref switch plus pierce height to give correct pierce height above the metal

an output is then given to the torch on relay. starts plasma arc and pierces metal
the plasma outputs an arc ok signal back to control to tell control it is on once arc is established
the control dwells for a parameter set time (to allow full pierce of the material)
the z is now lowered to the parameter set cutting height
motion commands given to start cutting movement

during movement the voltage divided signal is referenced continually and any change moves the torch up or down to keep the arc at the precise voltage.
the voltage / current loop is what makes for a perfect cut.
this movement must be virtually instantaneous to keep the arc set as required.

also this needs to be able to be disabled or reduced at very  slow feed rates ie tight corners to stop the torch diving down into the metal in corners where it is cutting faster than its moving
if its not broken yet, fit more gadgets!
Re: galil thc
« Reply #6 on: January 06, 2010, 06:50:08 AM »
by the way i have a candcnc unit here but its not a stand alone unit. it works with their interface and breakout only and outputs step/dir to motors only
i dont like the way their auto install removes any other saved profiles from mach so only their stuff turns up in mach loader!
they use serial com port for speed required to update.
if its not broken yet, fit more gadgets!
Re: galil thc
« Reply #7 on: April 18, 2010, 05:30:32 PM »
Is there any news on this thc in galil as I have begun working on the plasma again and would still like to use thc in the galil

Offline kcrouch

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Re: galil thc
« Reply #8 on: April 18, 2010, 07:51:51 PM »
Sorry,
No progress to report at this time. I could use some help determining what needs to happen.
Thanks,
Kenny
Having way too much fun! Something must surely be wrong.
Re: galil thc
« Reply #9 on: August 15, 2010, 11:34:29 PM »
I'm currently fitting a galil/mach combo to a woodworking machine (one router spindle, 10 vertical drills, 6 horizontal drills, grooving saw, 7 position tool changer), and I've just reached the point of controlling the three axes by mach (rapids at 65 (2560 inches)/min!). I really like the fact that with the galil plugin, mach is operating as the front end of a proper industrial control.

I also have a plasma table that runs off an old Burny 2.5 control, which works fine, but I find it limiting because the memory is so small, and it's really slow to download and calculate kerf offsets etc. I also want to add a torch height control, and I am attracted by candcnc's integrated mach solution, but I feel like it'd be a backwards step (no pun intended..) to remove the closed loop control and replace it with a parallel port solution- I'd really like to run it off a galil and retain the current drives and servos, but the integrated THC products don't work with the galil plugin.

The candcnc THC uses the serial port to relay arc volts etc back to mach- wouldn't this be relatively straightforward to do via the galil plugin, using one of the analogue inputs on the galil? I'm speaking from (my usual!) position of almost total ignorance about mach and the galil language, but in principle the THC is just an ADC (with all the noise supression etc around it), isn't it?

If Tom Caudle at candcnc did a galil-plugin version of his THC, surely it would be an extremely attractive retrofit for all the thousands of commercial servo-based plasma tables already out there (particularly since the existing analogue drives could be retained)?

X and Y axes, as well as an integrated servo-driven torch lifter, all controlled by the very fast bombproof galil.... I'd buy one. Please Tom!