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Author Topic: Plasma Application, Mach3 torch height control.  (Read 123721 times)

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Re: Plasma Application, Mach3 torch height control.
« Reply #30 on: March 19, 2009, 04:46:55 AM »
I use VCP with a self modified P.P. it's work in progress but it does work.
I have a tool setting macro I got from the good people  on the forum and it works really well for setting endmills on the router side, all it does is when it touches down it closes , like a set of contacts, just thought it could read through the torch and earth ground so when the two touch it pick up that closed curcit and run the macro then run on into the program.( just a thought.)

And yes very hard to read the brains ... I must ask what three signals are we picking up..IE: pins 44,45,46  I thought it was only the 0v-3.3v on one of them. ( I must go back and read your other post as I thought I was close to using this)

Thanks again
Dave
Re: Plasma Application, Mach3 torch height control.
« Reply #31 on: March 19, 2009, 09:21:29 AM »
dave,

with respect to the signals, i have connected the analogue signal from the voltage divider to pins 44,45,46, so that i can get more readings to average the reading from, these are read into the brain using modbus addresses 124,125 and 126 i think, these will give values between 0 and 1035 depending on the voltage of the signal from the voltage divider, 3.3v being 1035 and 0v being 0.

as far as the height sensing goes yes you could use that system, i think some comercial systems use it and its known as ohmic initial height sensing, do a search for it, i know some people slag it off and say it doesnt work if you plate is even a little dirty, i have no experience so i cant comment, also consider if having a wire connected to the plate to sense with is a good idea when you let it have tens of amps and hundreds of volts when you are cutting, sure there is a way round that with a bit of thought.

matt
Re: Plasma Application, Mach3 torch height control.
« Reply #32 on: March 23, 2009, 02:34:58 AM »
Matt, Yesterday I did get parts of it working...I put a pot on the pokeys and I could see my brains (yours with some mods) working, and I could make a thc dro give me range, but every time I would load Gcode (to play with and make z move) I could not make my dro move any more...Is it needing to be happy with torch okay signal first???
it could be my screen set to, its a mess.
Dave
Re: Plasma Application, Mach3 torch height control.
« Reply #33 on: April 12, 2009, 09:56:06 PM »
Hi Dave,

Sorry its been so long, since we last spoke ive moved to California for work, i think the reason you are getting that will be to do with having thc mode turned on and off, since you must have this on to allow the axis to be jogged up and down whilst g code is running, the ability to do that is unique to thc mode since it could potentially be very dangerous if you could just jog an axis whilst the code is running, i hadthe same when i was testimng at one time and i cant truthfull remember what i did to get it to work but its in that area, unfortunately i cant take a look either since im over 5000 miles from my machine which makes me sad!!

i should be able to get online more again now so let me know how far youve got

matt
Re: Plasma Application, Mach3 torch height control.
« Reply #34 on: April 16, 2009, 01:18:45 AM »
hi all
i have just build a 10 foot x 5 foot plasma cutting table  but i have a problem .
i am using an air cylinder for my plasma torch up and down  i want to control this in mach 3 .i am using an air solenoid valve to operate my air cylinder.
what i want is  =        the  torch  will nominally be in the up position =  this is proved by a limit switch =
travel to start off cut  =    torch down   =   this is proved by a limit switch =plasma on =time delay for piercing =
cut job = plasma off =torch  up =proved by limit switch .  move to next job . would be very grateful  if anyone can tell me how to do this  regards
Re: Plasma Application, Mach3 torch height control.
« Reply #35 on: April 16, 2009, 06:35:52 AM »
Matt
Glad to her from u again....5000 miles way from home is a Long ways, I hope Its not for to long.
I had to put the THC to the side to to get other projects done...Check back often as I need to get back to this soon.

donnellytony
Never herd of anyone using a air cylinder to control THC...do u think this will be very accurate ???.


Dave
Re: Plasma Application, Mach3 torch height control.
« Reply #36 on: May 02, 2009, 02:56:34 PM »
Dave,

im gettin tot he internet somewhere between once a week and once every 2 so thats why ive been quiet, im working with a custom harvester in CA so we are busy at the moment and will be for the next few weeks then ill get to it more often, we will hvae to pick it up again then since ive forgotten most of what we talked about, i wont be back to my machine until christmas!!!

matt
Re: Plasma Application, Mach3 torch height control.
« Reply #37 on: May 06, 2009, 02:47:39 AM »
Matt U have Mail in your hotmail box
Dave
Re: Plasma Application, Mach3 torch height control.
« Reply #38 on: May 11, 2009, 03:20:28 AM »
Ok I have this poject working but I have one problem...going through the brains on the torch up and down comand the Z axis is very jumpy...have not tried it with g code just on test bed...Maybe Scott AKA PAPABEAR can help with this?
If I use the shuttle All axis are smoth and liner....it is only when the brain turns on the torch up or down...
Re: Plasma Application, Mach3 torch height control.
« Reply #39 on: June 01, 2009, 02:57:44 AM »
I have to tell all that this works very well.
 Matt has found a very inexspensive way to have DTHC
keep a watch out for further updates.