Another plasma component...

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7 years 6 months ago #130318 by Zultan
Replied by Zultan on topic Another plasma component...
Phil

Ok, I'm dumb, saving works fine you just have to hit enter after changing a value. Saving works on both renamed and original named machine. Sorry for wasting time.

Glenn
The following user(s) said Thank You: phillc54
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7 years 6 months ago #130319 by phillc54
Replied by phillc54 on topic Another plasma component...
Thanks Glenn,

Yes, that seems to be a GladeVCP thing, it does work OK if you use up/down arrows.
I had just finished testing with a renamed machine...


Cheers, Phill.
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7 years 6 months ago #130320 by islander261
Replied by islander261 on topic Another plasma component...
Phill

I managed to do a few (9) line tests today. The results were mixed. But first here is the test program:
Code:
O<xline_test> sub G91 G0 X0 Y0 M3 S100 G01 X6.0 F220 M5 G90 (G01 Z 1.0) O<xline_test> endsub M2
This was launched as a MDI button from the bottom of the MDI screen.

I had a bunch of trouble using the dry run button (something I will never use in production work). It needs to show a change of state when it is active. Things got very confusing when trying to use it, most likely operator error. I had to shut down and restart gmoccapy to re establish predicable behavior.

While the probing test worked reliably on clean dry sheet things didn't go so well on a dirty wet one. Problems with the torch going down to the sheet surface with the Ohmic Probe LED coming on and then the torch just moving +/- .005" up and down by the DRO. The Ohmic Probe LED would sometimes briefly change state. It would do this until 30 second timer had timed out and then raise the torch.

The line tests proved less than reliable, the best I did was three in a row without a problem. Most of the problems involved some sort of probing failure. Sometimes the failure was as above but with a twist. Because there is no timer to force a time out the only way to stop the torch bouncing was hit the program stop button. At this point retries resulted in the same failure even after cleaning of the torch and material. The only way to recover correct operation was to shut down gmoccapy and restart it. On several tries the torch would move part way down and stop and fire well above the sheet surface. Stopping the program sometimes fixed the problem and sometimes didn't. Twice at the end of the cut the torch dove into the work piece only to raise up again. Once to the starting position and once into the upper limit switch. I expected the torch to raise to the safe height between cuts, some times it did and sometimes it didn't.

The good news is that THC appeared to work very well, I got the pgain up to 40 and the deadband at .1v and had no sign of oscillation and the height control was solid at the set point. The Z axis did not appear "nervous" at all. Halscope plots showed no sign of hunting or overshoot. The corner hold LED came on at the end of the cut as it should. I am very happy with how the THC works with the straight lines given the terrible time I have had previously with the EO branch. I now need to get a PP working for the plasmac branch so I can test with one of my normal pieces.

I don't know what I did but the configuration and materials files are now working correctly!

I need some guidance on what information I need to collect for you. I just don't have a good enough understanding of the plasmac component to do more than start looking a random signals.

John
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7 years 6 months ago - 7 years 6 months ago #130322 by phillc54
Replied by phillc54 on topic Another plasma component...

islander261 wrote:
I need some guidance on what information I need to collect for you. I just don't have a good enough understanding of the plasmac component to do more than start looking a random signals.

And conversely I don't know enough about plasma cutting to know what questions to ask...


John, thanks for all your testing it is at least steering me in the right direction.
Could you increase the debounce.0.delay to 2 in plasmac.hal to see if that makes any difference to probing, you may need to slow the probe speed down a little to compensate for the extra overshoot.
EDIT: Actually if you have a floating head it may be worthwhile trying something like 10...

Cheers, Phill.
Last edit: 7 years 6 months ago by phillc54.
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7 years 6 months ago #130328 by islander261
Replied by islander261 on topic Another plasma component...
Phill

I was really impressed with how well the THC worked, right now I am sure it is the best I have seen with any equipment I have owned.

Ok, I will increase the debounce time and try it. I actually went as high as 5 yesterday when chasing my tail. My floating head has nearly .25" in compliance so slowing down the response isn't a problem. My table is in rough shape right now because I don't have the couple of days to remove,repair, replace and re-level all the slats right now. So this is a good real world test in poor conditions.

My present system when probing rapids the torch down , this maybe from safe Z or from G53 Z0, to just above the thickest plate I can cut (i have no idea how I will get it on the table) .650" then proceeds at slow speed until contact is made. Then I move it down another .005" just make sure the contact is good. I then slow the speed down by 16 and raise the torch until contact is broken.

I have used several systems that used the no Z start the THC with M3 and end with M5, and all suffered from horrible IHS because of poor probing. Please look at the Gcode I posted a while ago about for probing. I didn't get to that point by accident. I can post an example of the Gcode my present production system uses if you want. Probing is easy if you only ever use 6-8mm and thicker plate (so is cutting in general).

Questions now. At what height is the torch supposed to go at the end of the cut? When cutting a file we want the torch to go to safe Z between cuts and at the end of the file we want the torch to go to G53 Z0, the same as error conditions. Even the commercial systems that use external THCs re synchronize the work piece top surface (G54 Z offset) at each probing, some at the probing and some at the end of the cut.

I am going to have to hack you plasmac_monitor code, my old eyes can't deal with the low contrast/low brightness arc voltage display! Actually once this is working well and stable I will most likely move all indicators to the plasmac_monitor code and put both Gladevpc tabs behind the preview tab.

John
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7 years 6 months ago #130329 by phillc54
Replied by phillc54 on topic Another plasma component...
Thanks John, I am sure we will get there eventually.

My present system when probing rapids the torch down , this maybe from safe Z or from G53 Z0, to just above the thickest plate I can cut (i have no idea how I will get it on the table) .650" then proceeds at slow speed until contact is made. Then I move it down another .005" just make sure the contact is good. I then slow the speed down by 16 and raise the torch until contact is broken.

I was just about to ask the sequence of your ohmic probing, I see now that I need to make it different than the float switch...
This exposes my total inexperience with cutting.

I have used several systems that used the no Z start the THC with M3 and end with M5, and all suffered from horrible IHS because of poor probing. Please look at the Gcode I posted a while ago about for probing. I didn't get to that point by accident. I can post an example of the Gcode my present production system uses if you want. Probing is easy if you only ever use 6-8mm and thicker plate (so is cutting in general).

I shall take a peek.

Questions now. At what height is the torch supposed to go at the end of the cut? When cutting a file we want the torch to go to safe Z between cuts and at the end of the file we want the torch to go to G53 Z0, the same as error conditions. Even the commercial systems that use external THCs re synchronize the work piece top surface (G54 Z offset) at each probing, some at the probing and some at the end of the cut.

Between cuts the torch goes to safe height (in the config tab) above the highest point encountered on the cut.
At the end of the job the torch goes to the original Z start height.( the height Z was when it received the spindle on signal)

I am going to have to hack you plasmac_monitor code, my old eyes can't deal with the low contrast/low brightness arc voltage display! Actually once this is working well and stable I will most likely move all indicators to the plasmac_monitor code and put both Gladevpc tabs behind the preview tab.

When you finish hacking the Gmoccapy config I would be happy to use that as the sample config if you agree. I have never used Gmoccapy before and actually find it a bit daunting...


Cheers, Phill.
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