Large format heated bed + 3.4rc1 and Error: Heater 0 faults

madeinta1wan

Hi all,

After upgrading to 3.4rc1 I've been really struggling to reach 55-60 degrees after running auto-tune half a dozen times. I've adjusted the dead time until I get an 'Error: M307: bad model parameters' error, adjusted the R value all with seemingly little effect on the heating rate.

The bed I'm heating is 3200mm long and divided into three sections. Previous to the update there was a steady temperature increase and now the heating only seems to work 2-3/10 times if the bed section is started from room temperature. If the bed error is cleared and the section turned back to active while warm (35-45) the temperature seems to struggle to heat smoothly, fluctuates around the 'warm' temperature and slightly decrease before another error/fault arises.

I've tried setting the auto-tune from room temperature to S75 with the idea that the elevated temperature might give different PID results but now the auto-tuning won't reach the set temperature and cancelled with the message 'Auto-tune cancelled because target temperature was not reached' .

I've left one section with the previous M307 code and have tried using that for the other bed sections to no avail, nearly every attempt to heat the bed(s) fails.

; Heaters
M308 S0 P"temp1" Y"pt1000" A"bed Heat1"        ; configure sensor 0 as thermistor on pin temp0
M950 H0 C"out2" T0                             ; create bed heater output on out0 and map it to sensor 0
M307 H0 R0.070 K0.416:0.000 D22.44 E1.35 S1.00 B0                 ; disable bang-bang mode for the bed heater and set PWM limit
M140 P0 H0                                     ; map heated bed 0 to heater 0
M143 H0 S90                                    ; set temperature limit for heater 0 to 90C

M308 S1 P"temp0" Y"pt1000" A"bed Heat2"        ; configure sensor 1 as pt1000 on pin temp1 (T100000 B4138)
M950 H1 C"out1" T1                             ; create bed heater output on out1 and map it to sensor 1
M307 H1 R0.083 K0.405:0.000 D15.33 E1.35 S1.00 B0                ; disable bang-bang mode for the bed heater and set PWM limit
M140 P1 H1                                     ; map heated bed 1 to heater 1                              

M308 S2 P"temp2" Y"thermistor" A"bed Heat3" T100000 B4138   ; configure sensor 2 as thermistor on pin temp2
M950 H2 C"out3" T2                             ; create bed heater output on out2 and map it to sensor 2
M307 H2 A32.7 C156.4 D4.0 S1.0                 ; disable bang-bang mode for the bed heater and set PWM limit
M140 P2 H2                                     ; map heated bed 1 to heater 1

Any direction would be great.

Thanks

Nate

madeinta1wan

Hi,

Checking back in to see if anyone has any advice on how best to adjust the M307 code.

Previous to 3.0 I think it heated well with no issue and the new heater algo means that it really struggles to both Autotune and reach 70-75 degrees

M308 S0 P"temp0" Y"pt1000" A"bed Heat1"        ; configure sensor 0 as thermistor on pin temp0 T100000 B4725
M950 H0 C"out1" T0                             ; create bed heater output on out0 and map it to sensor 0
;M301 H0 P-10 I0.2 D50 T0.3
M307 H0 R0.051 K0.098:0.000 D32.76 E1.35 S1.00 B0
; old M307 H0 R0.066 K0.191:0.000 D45.54 E1.35 S1.00 B0 ;M307 H0 R0.076 K0.292:0.000 D42.95 E1.35 S1.00 B0 ;M307 H0 R0.070 K0.416:0.000 D62.44 E1.35 S1.00 B0                 ; disable bang-bang mode for the bed heater and set PWM limit
M140 P0 H0                                     ; map heated bed 0 to heater 0
M143 H0 S90                                    ; set temperature limit for heater 0 to 90C

That's the current setting for one of three heat beds.

Thanks in advance,

Nate