Wrong Temp Monitored at Chamber Heater Fault

baua1024

@jay_s_uk Good to know that this is just a display issue. It's a weird issue then as the patchontes say that the reading time of the heater has been increased but it feels like it has been reduced as the chamber temp is rising VERY slowly as the heating element is not super powerfull. I even get negative readings due to fluctuation. Is there a way to disable this temp rising reading?

jay_s_uk

@baua1024 you might want to take a look at this https://forum.duet3d.com/topic/26733/3-4b7-7-chamber-heater-faults

baua1024

@jay_s_uk Thanks! I just had a read through it and unfortunately the C parameter got deprecated for the final 3.4 release. I will have to play with the E/K parameters although it reads like they have a different purpose(Cooling Curve) than the C.

baua1024

@jay_s_uk So I played around with E and K but I couldn't get the heater to stay on for longer without having the same error again. I also increased the dead time to 45 without any change. I think I don't understand how E and K fundamentally work. In the documentation there was the C parameter which simply said how long in seconds it would take for the heater to reach temperature but it was deprecated in favor for K and E. The docs say this is the formula: K*((Th-Ta)/100)^E. What is taken as the ambient temperature? I'm getting a bit frustrated as the only way I can heat the camber currently is manually increasing the temp by 1C at a time.

jay_s_uk

@baua1024 whats your current M307 line for the chamber heater?
I don't have one but I would suggest looking at changing the R value to something below 0.01 and increasing the dead time

baua1024

@jay_s_uk My current line is "M307 H2 B1 R0.016 D60" E&K value don't positively influence the successrate. Also all parameters seem to influence each other. So i can't go lower on R than 0.016 but if I set E&K on something i can't even go lower than 0.1.
I changed the Deadtime to 330 (that's the max) and this way it takes quite a bit longer until the fault occurs.

martin7404

@baua1024 With 3.4 I got this error only once for 48 hour printing already
My chamber heater is this link text
run trough SSR, I am using standard E3d V^ thermistor
this is my config line

M308 S2 A"Chamber" P"temp2" Y"thermistor" T100000 B4725 C7.06e-8
M950 H2 C"out2" T2                                 ;
M307 H2 A11 C99000 D2000 B1   ; 
M141 H2
M143 H2 S70

baua1024

@martin7404 Thanks! I will give it a shot. My heater element is 300W so it's fairly similar. I'm curious about the C parameter though as the docs say it's not supported anymore.

martin7404

@baua1024 it is left from older version, my point it trigered this error only during start of a print in a cold morning in the shop 20 minutes in.
Before that 20 hour print was finished

baua1024

@martin7404 Thank you Martin! With these values I can get it to heat up until 70C without any errors. I still wish there would be a better solution like a "dumb" heater but at least I can work with it now