Pierce delay not always working.

[Jason@bc]

Hello All,

This is my first post here, I'm having trouble with my cnc plasma table, I'm using sheetcam and command cnc. It looks like my pierce delay is not working as it should; it allways works on the first part tht I cut, but on the others it is not even pierced right and starts moving the torch allready.
Anybody else having these issues?

[Jason@bc]

[quote=Jason@bc post_id=29527 time=1638815163 user_id=4500]
Hello All,

This is my first post here, I'm having trouble with my cnc plasma table, I'm using sheetcam and command cnc. It looks like my pierce delay is not working as it should; it allways works on the first part tht I cut, but on the others it is not even pierced right and starts moving the torch allready.
Anybody else having these issues?

[robertspark]

it is not likely to be a sheetcam thing

post your problematic gcode.

it sounds like the thc is not enabled and it's not waiting for the arcok signal.

gcode is just machine code / a sequence of events..... what or how your machine interprets it is up to the machine.

is commandcnc not candcnc .... it so you will probably get more help on their forum or that of plasma spider

[Jason@bc]

I tried plasma spider and they directed me here.

[robertspark]

I tried plasma spider and they directed me here.

I frequent both forums, you can PM you problematic file / post the gcode and someone will try to help either here or over at plasmasider.

plasmaspider gets more foot fall, and there are a lot of users of different things.

[Jason@bc]

Here is the g-code file.

[Les Newell]

The pierce delay is the same for each pierce in the code. It is possible that your plasma cutter needs a longer pierce delay. Try increasing the pierce delay.

Do you have the arc OK signal connected up? That should make your pierces more consistent.

[Jason@bc]

This also happens on pierce delays that are 1.5 to 2 or more seconds, and yes my arc ok signal is working.

[robertspark]

what motion controller and CNC software are you using?

[Les Newell]

Is it actually waiting for the time you specify? For instance if you set it to 2 seconds do you see it wait for 2 seconds?

[Jason@bc]

Robert, I'm using Command CNC for running g-code, Linux software.
Les, it allways works on the first pierce of a job, and after that it looks like the torch starts to move as soon as the arc fires, when I have it set to
1.5 seconds or something like that, yes the torch doesn't start to move until the delay time is over.

[robertspark]

for command cnc you are also best to ask on the CandCNC forum as they will give you good support or ideas of what the problem may be:

https://www.candcnc.net/supportforum/index.php

it is their software afterall..... gcode is just a script..... provided G4 Pxxxx is there the machine should stop and wait. Provided THC is enabled the controller should wait for arc OK before starting the G4Pxxxx countdown / before moving.

[Les Newell]

I suspect your plasma takes less time to strike the arc on the first pierce. Can you get away with setting the pierce delay to be long enough to get the correct pierce on later pierces. This does mean the first pierce will take too long. If that works I can modify the post to shorten the first pierce.