@Phaedrux said in trigger height always changes:

@ianborg said in trigger height always changes:

G31 X37 Y0 Z0.98

Your G31 is missing the P value. Add P25. Not sure what the default is, or if this would make a difference, just something I noticed.

I'd also try reducing your Z max feed rate. Try 500 and see if it makes an improvement.

Also check your BLTouch mount to ensure that it's stable and fully vertical. Also the base of the probe should be ~2mm above the nozzle tip for best results.

that may have actually helped I rebooted 3 times and got 1.1x trigger heights each time. which is what i would have expected and wasn't seeing. so i'm going to adjust and try it all again.
1 question, my bltouch is set to be 8.3 mm above. most of my google searching says that's the number. i printed a 8.3mm jig and used that to set the height. is there something specific with the duet that it has to be 2mm??
appreciate the help!

M307 H0 R1.0 K0.250:0.000 D5 E1.35 S1.00 B0
been trial and erroring this.. that setup seems to heat up fast and not give a fault.

M307 H0 R1.0 K0.250:0.000 D5 E1.35 S1.00 B0
been trial and erroring this.. that setup seems to heat up fast and not give a fault.

@droftarts

got me again today, you can see it was almost to 90c
then
Heater 0 fault: temperature rising too slowly: expected 0.40°C/sec measured 0.12°C/sec
I set my m570 more aggressive.

I don't think 3 minutes to 90c is long to wait at all. sure I'd love it faster, but there are limits to how fast you can heat something up.

hey what do you know.. no faults after adding m570 command, default i think was 3 seconds, i set to 10 and number of times set to 10 and it's off an printing.
it took 3 minutes to go from 20c to 90c, as i watched, it appeared to go slower as it approached set temp. so I'm guessing I can tune it better. but 3 minute is fine for me to heat up.

Looking through more post and docs, i think M570 is going to be my friend.
am going to try that out

@gloomyandy appreciate the reply. No fans running during warm up.
the bed does heat up just fine and holds the temp during prints perfectly.
i just get a fault that it's taking too long to heat up, when I searched the forums, I see a few other folks
with the same / similar setup (750w heaters) also mention slow heating or issues. I don't have any issues waiting as it doesn't take all that long. my problem is duet is generating a fault and saying it's rising too slowly. I would like to make that go away, if it take 5 minutes then fine. i just don't want the fault, i clear it. heat the bed up and start the print and it's fine from there.

@jens55 appreciate the reply. In my case, if I heat the bed before i print. it's fine
so that would rule out connector issues. once it's up to temp, it stays there until the print is over. that will rule out the thermostat. I think it's my PID settings are not right, I'm just not sure what i need to tweak, I've ran auto tune many times, but the values are fairly similar each time, yet i get the heating too slowly message.

duet3d v2 latest firmware
I have a 300x300 aluminum bed with magnets and magnetic build plate.
heating source is 750w mains (120v) silicon heating pad
hooked to a uxcell ASH-25DA Solid State Relay 4-32VDC to 24-480VAC 25A Single Phase SSR DC to AC Relay
I get a heater fault almost every time i print. I have to heat up the bed to the desired temp and once it reaches, it stays, but if i start a print and the bed isn't heated, i get a fault.
"Heater 0 fault: temperature rising too slowly: expected 0.43°C/sec measured 0.12°C/sec"
I have tried PID auto tune many times and even when i plug the suggested numbers in, i still have issues.
looking for suggestions?
current settings.

; Heaters
M308 S0 P"bed_temp" Y"thermistor" T100000 B3950 C0 R4700	; define bed temperature sensor                    
M950 H0 C"bed_heat" T0
M140 H0
M143 H0 S120 ; set temperature limit for heater 0 to 120C
M308 S1 P"e0_temp" Y"thermistor" T100000 B4725 C7.060000e-8	; define extruder temperature sensor
M950 H1 C"e0_heat" T1 ; heater 1 uses the e0_heat pin and sensor 1
M143 H1 S300                           ; set temperature limit for heater 1 to 280C
M307 H0 R0.797 K0.250:0.000 D7.14 E1.35 S1.00 B0
M307 H1 R3.615 K0.413:0.000 D2.40 E1.35 S1.00 B0 V24.6

also of note, after having "heater issues" with my revo, i purchased a replacement heater and things seemed to be fine for a while. I had to some noise issues which was the result of a Y bearing rod rubbing. i fixed that and tried to print again and that's where these issues started. so i figured I need to re-calibrate everything, and ended up with this issue I posted about. after thinking it was fixed, i tried some more prints tonight and it really has smelled up my office. i chalked it up to the filament and threw on a known good roll. as I began to extrude 100mm, it was nearly falling out of the nozzle. I then saw the temp jump to 240 c and got a heater fault.. hmm as i touched the wires, yep the temps start moving all over the place.
so I have an issue with the heater, thermistor or wiring. the smell probably was because the filament was being heated way to hot and the temp readings were false. and that also of course explains, why things seemed fine and now all of a sudden all kinds of PID tuning issues.
so i posted this incase anyone finds it helpful in the future.

@deckingman no - nothing was in config-override.g file
interesting result tuning just the heater worked and gives no error when printing now.
it also only took a few minutes where the other way was taking 30-60 minutes.
so i guess i'm good now. thanks for the replies.

11/7/2022, 8:31:13 PM	Auto tuning heater 1 completed after 3 idle and 5 tuning cycles in 572 seconds. This heater needs the following M307 command:
 M307 H1 R0.741 K0.195:0.000 D5.31 E1.35 S1.00 B0 V24.6
Edit the M307 H1 command in config.g to match this. Omit the V parameter if the heater is not powered from VIN.
11/7/2022, 8:27:44 PM	Auto tune starting phase 3, measuring
11/7/2022, 8:24:20 PM	Auto tune starting phase 2, settling
11/7/2022, 8:21:46 PM	Auto tune starting phase 1, heating up
11/7/2022, 8:21:41 PM	m303 p1 s200 h1
Auto tuning heater 1 using target temperature 200.0°C and PWM 1.00 - do not leave printer unattended

@gloomyandy I will get some screen shots posted asap
thanks!