Heater 1 error after M303 T0 tune with fan on
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I recently upgraded my FFF printer running on a Duet 3 MB6HC with SBC to RRF 3.3 stable release. After the upgrade I retuned all heaters which ran fine for the heatbed (H0) and chamber heater (H2) but for the extruder heater (H1) I ran into a problem after completing the tuning. I am now getting the "Temperature rising too slowly" error.
The tuning command I used was M303 T0 S240 A50.0 F0.3. The tuning ran through all its cycles with fan on as well as fan off so I thought all was good. However after trying to print I started getting the Temperature rising too slowly error soon after the extruder heater was switched on. After a lot of back and forth I ran the M303 H1 S240 A50.0 tuning which does not do a tune with the fan on. After that I stopped getting the error but obviously I have no compensation for when the fan switches on during printing. The fan is not on during the heat-up phase. Both tuning commands were run with the heatbed and chamber heaters at temperature.
My H1 heater config is :
M308 S1 P"spi.cs0" Y"rtd-max31865"
M950 H1 C"out3" T1
M307 H1 B0 S1.00
M143 H1 S450My H1 heater config override after the second (H1) tuning is :
M307 H1 R2.218 C344.600:344.600 D8.70 S1.00 V23.6 B0With the T0 tuning it was something like :
M307 H1 R2.218 C344.600:61.000 D8.70 S1.00 V23.6 B0I have the M501 command at the end of my config.g file.
Any idea on what the problem could be?
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@h975 said in Heater 1 error after M303 T0 tune with fan on:
My H1 heater config override after the second (H1) tuning is :
M307 H1 R2.218 C344.600:344.600 D8.70 S1.00 V23.6 B0
With the T0 tuning it was something like :
M307 H1 R2.218 C344.600:61.000 D8.70 S1.00 V23.6 B0The only difference between those is the second C parameter, and that is exactly as it should be. So the behaviour with fan off should be identical.
Are you certain that the fan wasn't accidentally left on when you tried to heat the hot end the first time?
btw the very large change in C parameter between fan off and on suggests that the fan is over-cooling the hot end.
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@dc42 said in Heater 1 error after M303 T0 tune with fan on:
@h975 said in Heater 1 error after M303 T0 tune with fan on:
My H1 heater config override after the second (H1) tuning is :
M307 H1 R2.218 C344.600:344.600 D8.70 S1.00 V23.6 B0
With the T0 tuning it was something like :
M307 H1 R2.218 C344.600:61.000 D8.70 S1.00 V23.6 B0Are you certain that the fan wasn't accidentally left on when you tried to heat the hot end the first time?
btw the very large change in C parameter between fan off and on suggests that the fan is over-cooling the hot end.
Yes the fan was definitely off when the extruder was heating up. I double checked a couple of times.
I will have to look at the overcooling but as I designed a new air distributor last week I will run a new tuning to see if the second C value comes up.
Could this cause a problem with the tuning though?
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@h975 Ok, I did another tune with the new air distributor which brings the second C value up somewhat (to an 87.8).
After that I tried to run the heating cycle with the new tuning values (after doing an M500) which again gave the error.
I then followed this up by trying different 2nd C values starting at a value only slightly lower than the 1st C value and slowly reducing that. Initially none of that seemed to make a difference in the expected heating rate. (I still have a screenshot of the log from the console if you want to see that)
After that I retried the different 2nd C values while doing a reset of the board every time I changed the C value.
Doing this brought the expected heating rate down sufficiently to allow me to work with 1st and 2nd C parameters which are different from each other. I then slowly started reducing the 2nd C value to a point at which the heating cycle would again fail (at a 2nd C value of 120) due to the mentioned error. The lowest 2nd C value at which the system worked without the error (with a 1st C value of 345) was 130.
It therefore seems that the system expects a higher heating rate when there is a large difference between the 1st and 2nd C value even during initial heat up when the fan is off.
Shouldn't the heating rate with the fan off (given a specific R value) be determined by the 1st C value and by the 2nd C value in the case when the fan is on?
