Auto tune cancelled because target temperature was not reached

[TimVukman]

I recently switched to 24V from 12V. I am most pleased overall as the motors are pretty much silent at this point.

I replaced the hot end heater module, hot end fan, printed part cooling fan and the heated bed. The heated bed is larger than the old one, but it is clearly marked for wiring for 24V. It seems to be working fine.

The hotend is not. It is connected directly to the duetwifi and it does work in that it starts up. As indicated by the message in the subject line above, it does not get up to temperature during the auto tune.

It gets to almost 130C after the five minute window. I expected it to get up to temperature faster on 24V, than on 12V, but I'm don't think it is the same wattage as the 12V module was.

My heater section is:
; Heaters
M305 P0 T100000 B3988 C0 R4700 ; Set thermistor + ADC parameters for heater 0
M143 H0 S240 ; Set temperature limit for hotend heater 0 to 240C
M305 P1 T100000 B4725 C0 R4700 ; Set thermistor + ADC parameters for heater 1
M143 H1 S120 ; Set temperature limit for bed heater 1 to 120C
, but that may be from the original 12V setup.

Since M303 failed, I don't expect any new information was written to the file.

Is there documentation on how to calculate the value for B?

Thanks
Tim

[aidar]

Hi

By default H0 is bed heater, H1 is first hotend heater and so on. With your config you limit your hotend heater to 120C, so it can not reach much more duering auto tune.
And B value is termistor value, it has nothing to do with voltage. If it worked with 12v, it will work with 24 v as well.
In online configurator there is calculator for termistor values in heater section, but you have to know some resistant-temperatures values for your termistor to let calculator to find B value.
Sorry, english is not my first language, so i just hope i made it clear enough.

[TimVukman]

Hi aidar

Your english is fine and I understand what you are saying. Thanks for clearing up the heater numbering. Your response is appreciated.

Tim

[TimVukman]

I made the changes I thought would fix the heater settings

; Heaters
M305 P0 T100000 B3988 C0 R4700 ; Set thermistor + ADC parameters for heater 0
M143 H0 S120 ; Set temperature limit for bed heater 0 to 120C
M305 P1 T100000 B4725 C0 R4700 ; Set thermistor + ADC parameters for heater 1
M143 H1 S240 ; Set temperature limit for hotend heater 1 to 240C

I received the same autotune failure message.

Autotune ran for exactly 5 minutes, the nozzle temp reached 127.6 and it stopped because it took too long. I had set it to 200C.

Can I change the time to 10 minutes instead of 5?

Thanks,
Tim

[dc42]

What M303 command did you send? Perhaps you limited the PWM.

[TimVukman]

Thanks for your reply.

I used
M303 H1 S240

which I got from
https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control

I changed S240 to S200 because I read that it's better to set the temperature for what you are going to use, or even set up different profiles based on the specific filament and the results of testing to identify the ideal temperature.

I have never played with these settings before, or had a problem with the default.

Should I run the configurator again? I would think I can just key in the settings, but obviously the tuning has to pass first.

So, I'm kind of stuck

Tim

[dc42]

@timvukman said in Auto tune cancelled because target temperature was not reached:

I used
M303 H1 S240

That's correct. It sounds as thought your hot end heater is under-powered, which is unusual. I suggest you check the connections. If you have a multimeter, measure the resistance of the heating element.

[TimVukman]

Hi:

Fresh battery in the meter, I get 13.5 ohms.

Tim

This is what I bought for the conversion + the heated bed.
1 x E3D Ceramic Cartridge Heater
(Voltage, Wattage: 24V, 40W)
1 x 24V Cooling Fan - Ball Bearing - 30mm x 30mm
1 x 24V Cooling Fan - Ball Bearing - 40mm x 40mm
1 x Power Supply - 24V, 400W

[TimVukman]

I am so sorry. I have to send a nasty note to my supplier. I ordered a 24V 400W power supply as noted above. After sending the resistance info I thought I should indicate what the duetwifi is showing.

It shows 12.4V. It also says 12V 400W on the case.

I will have to get them to send me a replacement that is 24V.

I'll be away for a week, so I will get back to you.

Tim

[TimVukman]

Hi:

Autotune Passed

Warning: Heater 1 appears to be over-powered. If left on at full power, its temperature is predicted to reach 518C.
Auto tune heater 1 completed in 333 sec
Use M307 H1 to see the result, or M500 to save the result in config-override.g

M307 H1
Heater 1 model: gain 493.7, time constant 225.4, dead time 5.4, max PWM 1.00, calibration voltage 24.4, mode PID, inverted no, frequency default
Computed PID parameters for setpoint change: P15.1, I0.434, D57.0
Computed PID parameters for load change: P15

Sorry to have wasted your time. I will be sure to check the voltage when the replacement supply arrives.

Tim

[T3P3Tony]

The value for B in M305 is for the thermistor beta value, not the heater model

Try removing the current M307 valuer from your config-override.g and then running M303 again.

also check out: https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control#Section_Troubleshooting_auto_tuning

[dc42]

@timvukman said in Auto tune cancelled because target temperature was not reached:

Hi:

Autotune Passed

Warning: Heater 1 appears to be over-powered. If left on at full power, its temperature is predicted to reach 518C.
Auto tune heater 1 completed in 333 sec
Use M307 H1 to see the result, or M500 to save the result in config-override.g

M307 H1
Heater 1 model: gain 493.7, time constant 225.4, dead time 5.4, max PWM 1.00, calibration voltage 24.4, mode PID, inverted no, frequency default
Computed PID parameters for setpoint change: P15.1, I0.434, D57.0
Computed PID parameters for load change: P15

Sorry to have wasted your time. I will be sure to check the voltage when the replacement supply arrives.

Tim

I'm glad you solved it! I presume you reverted to the 12V heater cartridge.