Very new to Open Builds and CNC so be gentle I'm having an issue where when I run the hello world G-Code the relay will kick on with the M3S1000 command and then as soon as it pierces it will switch off again so I'm just left with a bunch of holes. I don't think this is an issue with the plasma cutter as I can physically hear the black box relay clicking off. I tried to run these commands manually to see if it had the same effect but there was no problem, M3S1000 would turn it on and M5 would turn it off as expected. I then thought that the G04 P0.5 might be the issue, but yet again this had no effect when I entered it manually. Any thoughts on this are appreciated as I am very much stumped at this stage. G-Code is attached. Thanks in advance.
Is $30=1000 in Grbl Settings? IS $32=0 (Its a plasma, not a laser) Is the Plasma Inverter a Blowback/LF type? (HF Plasmas generate tonnes of EMI) Is your pierce and cut heights appropriate - too far from the material and the arc will extinguish
Thanks for the reply 1. Yep 2. Yep, Laser mode disabled 3. Blowback Start 4. In line with the manufacturers recommendations (Which were nearly the exact same as the default open builds one)
With the plasma's power off, run an aircut and see if you still hear the relay clicking off. And if you have a multimeter, in continuity mode, over the relay terminals - might be better than listening for the click, see if it really opens?
There is no OFF commands in the gcode (at that point), so that is interesting. Does the TOOL ON button on the top menu in CONTROL trigger it to stay on?
Yep TOOL ON and TOOL OFF work perfectly. So does manually sending M3 and M5. Do you reckon reinstalling Open Builds control would help / eliminate the possibility of some software glitch etc.?
Unlikely to be software related no. But do upload a Grbl Settings backup, lets just take a peek. Grbl settings tab > Backup settings button is on the top toolbar
Are there any clues in the Serial Log when it stops, i notice Hard Limits is turned on, perhaps a Hard Limits alarm (will kill relay too), or a Grbl Reset?
Nothing in the serial log about hard limit. I reset the grbl settings but that had no effect. I also disabled the "limit switches installed" and saved that; still no change. What about resetting the EEPROM? Is that what you meant by 'Grbl Reset'? I'm not too familiar with the terms
no was referring to seeing Grbl reset (reboot) itself in the Log at the time it cuts off perhaps. Just for my own sanity, can you clarify: Replied as i lay awake last night going over this again and again, and assume that test was, as requested, with the Plasma itself removed from the equation. But as you didnt say that for certain i keep wondering. Just please confirm, with the plasma itself off (emi source) does it also just cut off shortly after being turned on? And if it was off in that earlier test, use the Serial Console and feed the gcode line by line (copy/paste) see if you can identify where it switches on (M3) and then off (after the m3 but before the next line, or after the first g1, or... Etc)
1. Yea no nothing in the logs I'm afraid. 2. The plasma cutter was (still is) completely disconnected from the machine. 3. I fed the G-Code line by line and it's the second G1 where it switches off. And I think I know why: I just noticed that at end of each G1 command is S1 but when I enter M3S1 the relay doesn't click on. I've replaced all the S1s with S1000 and I'm gonna test it now.
The file you posted above has the right S1000 at the end: So , uploaded the wrong file, or testing with a different file than the one provided? - i did check the file when you posted it.
Well now I feel incredibly stupid, I don't know how I even managed to get a file from openbuilds cam that had S1, I cut and pasted the hw.gcode to my USB stick then downloaded another one to upload here assuming they would be the same but somewhere my settings were different. Sorry for leading you on a wild goose chase, its working perfectly now. It's like they always say: 99% of the problems are between the steering wheel and the drivers seat. Just out of curiosity, does the relay only click on at S1000? or is there a range of values?
Reliably 1000. May turn on with less, but its not healthy to PWM the relay coil - its not the intended use case. With the relay/plasma its an ON/OFF situation - the relay cannot control output power. The S-Word is more useful for spindles connected via the 0-10v output, or lasers connected via the PWM output. Knowing you have a device that needs an ON/OFF signal, its up to you to ensure the gcode is only turning it on (M3S1000) and OFF (M3S0 or M5)
Other way round. If S<1000 Grbl outputs a PWM signal. You want a non-pwm signal holding the relay coil, thus you use S1000
