can i make an axis move?

[matttargett4]

hi,

ive been fidddling a bit more and yes you can, the only trouble is to do it you have to use the torch up and down inputs, Found in the input signals config page and these are simply on or off so there is no way of implementing the pid loop, unless you could control the duration they are on and off for, pwm in other words but i cant see how to do this with a brain so im trying it with just the on/ off commands. Ive not had much time to mess lately but im havent got pat the thing where once you have told a brain to press a button then youve got to tell it to stop pressing it at the end of the brain or it just runs on endlessly, have been looking at some of scotss counting examples etc and i think the answer is in there but i just havent got to doing it yet. Let me know if you have any thoughts

matt

[poppabear]

VMax,

     Here is my understanding (which can obvioulsy be wrong), but, It is my understanding with out a Plug in, then the "Z" is controlled up and down by an analog motor in relation to the Plazma current draw.

So, you would have a "Z" axis that is controlled UP and Down by Mach (the standard Z), and then another "Z-Head " that is controlled up and down by an analog motor that is driven through a PID loop that is in a PLC, or Plazma Controller, or from a "Plug in for Plazma", or some combination of the above.

It is my understanding that when "G-Code" is actually running in Mach3, The "Index" and "Head" of the Buffer are NOT together, and when they are NOT together, that disables any type of "Jogging" in standard Mach. BUT, if you write a Plug in, in which you CAN have direct control over jogging, then you CAN override this behavior. It is NOT wize to do so, and it will cause you problems. (Found out the hard way, when I started writing my Jog Plug ins).

I think Mach give Tourch/Plazma control signals that you can work with, but they are not step and direction signals.  Most of the stuff, and I think
Brian wrote an "Analog PID Loop" Plug in just for the above issues.  I think that Bob Cambel and that crowd that sell Plazma Boxes, all use some type of Current Adjusted Z-Head that is controlled as an analog PID loop somewhere.

scott

[vmax549]

HIYA Scott I may be wrong as well but I do remember it being discussed over at Yahoo.

Hello,
They only axis that you can change on the fly is the Z axis... The THC
is a very special case and is not available to the X and Y axis
Thanks
Brian


Hi:

No, while programmed motion is in control, no joggign is possible, the THC
correction is a special case in the code, any other axis would be ignored..
Also not a good idea to change the offsets as it runs. unknown what teh
effects woudl be, but not good I suspect.,.


Thanks,
Art


Just a thought, (;-) TP

[poppabear]

Food for thought it appears..........   I personally am not running a Plazma table or doing a control at this time, so I have no way to explore this further.
Perhaps some one is in the "Current know", can respond to this with more updated experiences than mine.
I was Unaware that Brian changed the Z for the THC stuff, so that being the case, I would like to know what combination of parameters, and steps are needed to do the above.............

scott

[matttargett4]

scott,

i have made the z adjust on the fly using the following "fast and dirty" method.

If you open the plasma profile that is with the standard download of mach 3, go to the config inputs page and scroll down the list, there are 3 inputs called "thc on" "thc up" and "thc down", i have assigned hot keys to these inputs to test its operation.

Back on the program run screen in one of the lower boxes where tool info or something appears in mach 3 mill there are some plasma controls, there is a thc on button ans a couple of other things.

In order to allow the axis to be moved up and down using the hotkeys assigned this button must be clicked on and the "thc on" input must be activted ( this is normally connected to the plasma cutter and recives a signal after the arc has pierced the metal and is ready to move, mach normally waits for this signal before executing the next command, just ensures the arc is stable and any voltgae/current spikes have settled after the pierce) then the hotkeys will move the axis up and down.

The only other thing is im not sure if you need to be in plasma mode in the general config window, i propably am in it if it wont work.

Im currently working on getting the brain to react to an analogue input and activate these inputs so it all works but have been a bit busy.

My description probably stinks so shout if you are unsure, the other thing i wondered is i assume when you refer to "brian" you mean brian barker? Just asking since there is a thc plugin authored by brian barker which i have looked at and appears to do something similar to what i am talking about and i wondered if this wasthe man to ask about how to use / manipulate it?

Thanks alot, hope this is turning out to be interesting for a few people

matt

[poppabear]

Yes, Brian is Brian Barker, he made a PID loop plug in, for plazma.

and thank you for your input, will file that tidbit in the old noodle..........

scott

[matttargett4]

scott,

glad i could help in some way, where do you think would be the best place to post try to speak to brian about his plugin? there was thread i found when searching the site about this that recieved no replies but nothing else?

thanks

matt