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24 Apr 2019 05:56 #131736 by rodw
Replied by rodw on topic Another plasma component...
Well this is strange. Nothing working for me. PLASMAC is getting into endless loops when probing. Using latest commit ef66f44

It does not seem to be respecting the probe speed at all. even when I slow it right down in the Gmocappy GUI, it still goes up and down like a yoyo at a great rate of knots. Its an endless loop. I see the GUI indicators for both Ohmic sensing and float switch come on.

I think I got one cut working out of 20 attempts.

The error I get is "ohmic probe detected before probing. program is paused"

Maybe it is probing too fast for my mechanical relays to enable the probe enable.. But then it should not be able to receive an ohmic probe signal...

New relays on order.

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24 Apr 2019 06:34 - 24 Apr 2019 06:39 #131740 by phillc54
Rod,
I just did a build from the branch and cannot fault it.
After reading what is happening several times I don't have a clue what it could be. Are they maybe solid state relays with a bit of leakage?

Cheers, Phill

EDIT: I read it again and they are mechanical...

EDIT2: Can you determine why the probe leds are coming on?
Last edit: 24 Apr 2019 06:39 by phillc54.

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24 Apr 2019 07:00 #131744 by rodw
Replied by rodw on topic Another plasma component...
Phil, This was working. There is an error somewhere in the code as the probing does not time out after a few tries. I kinda think its probing too fast and I can't slow it down. I suspect that before LinuxCNC can acknowledge the probing input, the float switch is triggered. It did fire twice and worked once with the torch disabled.

Funny thing is, it was working fine the other day. The first thing I did was do a git pull and it said it was up to date. I just can't remember if I cut with this config the other day. I think I did.

Are there any settings files that can be deleted? Maybe its memory is corrupt and as bad as mine!

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24 Apr 2019 07:06 #131745 by phillc54
Rod,
Is your probe height high enough, it is calculated as the height above the minimum soft limit?
Is your Z height near the top before probing?
When it moves down which should be at setup speed and a probe light comes on before reaching probe height does it move up near the top then go into pause?

Cheers, Phill.

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24 Apr 2019 09:13 #131746 by phillc54
John,
I would like to confirm these statistic values:
Cut Time is actual cut time from beginning of x/y motion after move to cut height until torch off at the end
Cut Distance is the length of x/y motion during Cut Time
Probe Time is from pressing run until start of move to Pierce Height (includes unsuccessful probes)
Pierce Count is total number of pierce attempts including failures (basically a torch on count)
Rapid Time is time spent doing G0 moves

Would you like anything else?

Cheers, Phill.
The following user(s) said Thank You: rodw

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24 Apr 2019 09:28 #131747 by rodw
Replied by rodw on topic Another plasma component...
Phill, thanks you'll be ruing the day that you decided to make this public but its one way to make a robust system!

I suspect the issue would be because of the probe height. My min soft limit is well below the slats. There is no guarantee I have a perfectly flat table height parallel with the gantry for the full length of the table.. I've always done a G92 Z0 to set the height. So I was working on probe height being above Z0. I think that means the probe height was below the material height.

Nothing goes into pause, it ends up in an endless yoyo loop and never stops.

So what has changed is the position on the table I am cutting at vs today and the other day. This leads me to another issue as I moved the material closer to the min limits to compensate for it.

I may not be doing it the right way so tell me how I should be doing it. Usually what I do is jog to the position where I want to start cutting from and issue a G92 X0 Y0. Sometimes I have added that to the beginning of my gcode. Previously the X0 Y0 position would be saved in the .var file and would persist between sessions.

With Plasmac, there is no .var file and the zero point (x0,y0) is not restored on the next startup as it used to be. I've found this an annoyance and it deviates from a standard config. If this had of worked, I could have left my ever diminishing test material at the back of the table and not had any problems.

I think the time has come to take my table off its casters and fit the leveling feet, and borrow a mate's engineers level and square the table properly.

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24 Apr 2019 09:48 - 24 Apr 2019 09:49 #131750 by rodw
Replied by rodw on topic Another plasma component...

phillc54 wrote: John,
I would like to confirm these statistic values:
Cut Time is actual cut time from beginning of x/y motion after move to cut height until torch off at the end
Cut Distance is the length of x/y motion during Cut Time
Probe Time is from pressing run until start of move to Pierce Height (includes unsuccessful probes)
Pierce Count is total number of pierce attempts including failures (basically a torch on count)
Rapid Time is time spent doing G0 moves

Would you like anything else?

Cheers, Phill.


One application might be to gather stats for quoting purposes. I would break the Pierce count up into successful, unsuccessful and total. That way you could average the probe time out for quoting. eg. if you had 1000 seconds of probe time 400 successful pierces and 100 unsuccessful pierces, you could calculate the percentage time to allow per pierce per failed pierce. So if you were using Sheetcam, you could run a job report with real production data per pierce that included an allowance for failures. This should generate a reasonably accurate production time for costing.

Also the percentage of failures might be a good indicator of remaining consumable life.

Just an aside. As a manufacturer, you really only have one KPI to measure and that is gross margin per hour. Assuming you set a target chargeout rate per hour you should be estimating your GM per job and comparing that with actual. Then you get feedback to send back into the quoting process so you are not working for nothing. This would be very powerful info if applied in a management sense. Get tit right, involve your staff and you will easily add 10% to 20% to the bottom line but that a bit out of scope on this forum... but it put a lot of money in the bank for me in a past life!
Last edit: 24 Apr 2019 09:49 by rodw.

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24 Apr 2019 09:59 #131752 by pl7i92
Replied by pl7i92 on topic Another plasma component...
i personly as i got pre piezo pilot ACR egnithion
use only a probe once and start at 4mm the tourch then go down to 2mm and THC takes over after 1sec
as i like to cricle in to the contour it is enoph to get a sharp good cut

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24 Apr 2019 09:59 #131753 by phillc54
Rod,
I have always set X & Y at zero by using the touchoff button, I have never used G92.
I have Z zero permanently at around slat level, and home is about 5mm from max height. The intent was not to move Z, but let the component do all Z motion
I think we may have to revisit probing, something along the lines of:
Initial probe from Z top at a faster rate, find top of stock then move to probe height (which would be height above stock) then do normal probe. All subsequent probes until the end of the job would only be from probe height. This makes for a slower initial probe but I feel it would work out much better and cause less grief.
We would need to get some consensus on this before moving ahead though.

Cheers, Phill.

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24 Apr 2019 10:21 - 24 Apr 2019 10:23 #131757 by phillc54

rodw wrote:
With Plasmac, there is no .var file

If you mean the [RS274NGC] PARAMETER_FILE in the ini file then it should be metric_parameters.txt (or imperial_parameters.txt) for all the sim configs.

Cheers, Phill.
Last edit: 24 Apr 2019 10:23 by phillc54.

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