Duet 2 Wifi Nozzle heater not stable
Hi all i have just upgraded my Anycubic Predator with a Duet 2 Wifi board and 7" Screen I have everything working apart from a very annoying problem I have run the Auto calibration on my nozzle heater and it will not stabilise if I ask the nozzle to be heated up to 200c the nozzle will heat up past that says 208c and when printing it is deviating up and down by a good 3 - 4 celsius the nozzle was a lot more stable with the original board has anyone come across this and can suggest a fix I can try many thanks.
@kenbigt I assume your M307 command for that heater outputs the result of the M303 (i.e. you have confirmed its applied?)
Try increasing the "D" parameter that the autotuning came to by 50%.
the temperature shot up to 210 then dropped to 197.5 this is a big part of the problem i print stuff at 230 -235 and if i let this continue i will melt my heater
; config-override.g file generated in response to M500 at 2019-09-10 17:41
; This is a system-generated file - do not edit
; Delta parameters
M665 L440.000:440.000:440.000 R227.000 H456.000 B185.0 X0.000 Y0.000 Z0.000
M666 X0.000 Y0.000 Z0.000 A0.00 B0.00
; Heater model parameters
M307 H0 A137.8 C533.3 D1.5 S1.00 V24.3 B0
M307 H1 A582.0 C154.9 D7.7 S1.00 V24.2 B0 can i confirm this is the D you were meaning
M307 H2 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H3 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H4 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H5 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H6 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H7 A340.0 C140.0 D5.5 S1.00 V0.0 B0
G10 L2 P1 X0.00 Y0.00 Z0.00
G10 L2 P2 X0.00 Y0.00 Z0.00
G10 L2 P3 X0.00 Y0.00 Z0.00
G10 L2 P4 X0.00 Y0.00 Z0.00
G10 L2 P5 X0.00 Y0.00 Z0.00
G10 L2 P6 X0.00 Y0.00 Z0.00
G10 L2 P7 X0.00 Y0.00 Z0.00
G10 L2 P8 X0.00 Y0.00 Z0.00
G10 L2 P9 X0.00 Y0.00 Z0.00
Yes that's the right D value. However, initial overshoot usually means that the gain value A is set too low. That can happen if you tuned the heater with the part cooling fan turned on, but you heat up with it turned off, especially if you don't have a silicone sock over the heater block.
If the hot end temperature oscillates when the printer is idle, increase D. If the temperature is slow to recover from deviations caused by outside influences, reduce D.
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@dc42 so i have to stop my cooling fan to do the calibration is that correct
@kenbigt sorry just want to be 100% understanding do you want me to turn of the cooling fan that stops heat creep i do not have the part cooling fan on just the fan that comes on and of with the nozzle heating up
@kenbigt no, you should do the calibration with both the part cooling fan and the extruder heater cooling fan running - so that you don't get errors when they come on during a print.
I have spotted in another post that the 40watt Heater that comes with the Anycubic Predator is to powerfull for the Duet 2 wifi setup is this true and if so what would you recommend as a setup
@kenbigt its not too powerful for the Duet - its just capable of getting very hot. Depending on how you use your printer and what you view of failing safe(r) is depends on if this is a probelm. many people use 40W heaters in aluminium blocks - if the heater is on full power and not controlled then it can get very hot.