Major bug in 1.18.1 “Heater fault” with high temperature on HotEnd ?



  • I have install 1.18.1 (from ver 1.09) and printed about 20 pieces with PLA ( 210 Celsius ) without any problem, but when I start to print ABS pieces ( 250 Celsius) then I got major problems 😞
    I've got the status “Heater fault” when I'm printing ABS and the printer are stopped after ~10 minutes.
    With ver 1.09 I have printing ~500 different types of plastic pieces, both ABS and PLA without any "heater fault" problem.

    After the first failed attempt I set M570 “Configure heater fault detection” to
    M570 H1 P10 T25
    (increased the default value ?, the pure command “M570” doesn't works, so I can't see the default values, except what I have reed on http://reprap.org/wiki/G-code for M570 command), but the problems didn't disappear and the printer get the “Heater fault” state again after ~10-15 minutes of printing.

    Now I start to be little frustrated, so I change the M570 values to
    M570 H1 P1000 T200
    But, after ~15-20 minutes printing the printer get in “Heater faults” state again 😞
    How could the printer get in “Heater fault” status with these extreme M570 values ?

    This time I was little more observant when I printing and notice that the heater temperature fall down from 250 C to 220-230 C when I printing (40mm/s feed rate).
    Strange, because I haven't these problems with ver 1.09.
    Are there some problems with the PID-regulations in ver 1.18.1 ? Has any default PID-parameter changes from ver 1.09 and 1.18.1 ?
    With 1.09 it could be difficult to reach 250C all the time when I printing ABS and the temperature could fall down to 245 Celsius and also sometimes to 240C, but never as low as 220-230 C.

    So I did a new printing attempt and decrease the feed rate from 40 to 30 mm/s, if the maximum power of the HotEnd cause the problem.
    (I using Ormeod 1 Duet 0.6 with the standard 40 W 12V heater.)
    But, I got the same result with “Heater faults” again after ~20 minutes printing.
    The temperature was set to 245C, but when I printing the temperature fall down to 220-230 C again.
    Printing ABS with 220-230 C is not good…

    I haven't change the default PID parameters either in 1.09 or 1.18.1.
    I using the hardware Ormerod 1 with Duet 0.6 board.
    I don't know what I should do now. Should I down grade to Ver 1.09 again to see if the problem disappear.
    I'm not 100% sure if this is a bug or a local hardware (wiring, heater) problem on just my machine.

    Why does it work perfect with PLA printing (210C), but not with ABS (250 C) printing ?
    Why does it work perfect with ABS before the firmware upgrade ?
    Could there be a combination of hardware errors (cables) and software bugs (PID controller and M570 command) ?
    Why could the printer not reach higher temperature than 230 C when I printing with ver 1.18.1 ?... temperature regulation PID-problems ?

    Any suggestions what I should do ?

    ======================
    Here are the web console message (“G-code Consol” on the GUI)
    12:42:52 File xxx.g selected for printing
    13:06:56 Error: heating fault on heater 1, temperature rising much more slowly than the expected 0.4 C/sec.
    Warning: Tool 0 was not driven because its heater temperature were not high enough or it has a heater fault
    13:06:59 Warning: Tool 0 was not driven because its heater temperature were not high enough or it has a heater fault



  • Hmm, maybe I should do some oscilloscope measurement over the HotEnd heater , when I'm printing, to see why the temperature only reach 220-230C instead of 250 C. If the heater is set to 250 C and the real temperature is only 220-230 C the PWM pulses should be close to 100 % modulation in ON-state, because the "I"-part (integration) should push the PWM close to 100% after a while.
    If I remember right the PWM of the HotEnd is using relative high frequencies (many khz ).


  • administrators

    I suspect that your print cooling fan is over-cooling the nozzle and heater block. What are your M307 H1 parameters? You may need to reduce the gain parameter to make allowance for the effect of the print cooling fan. Using a silicone sock over the heater block will also help avoid excessive cooling by the fan.



  • I found the problem 🙂
    I've used "M570 S999" command in config.sys, but this command is only valid for ver 1.14 or earlier.
    The first attempts the printer was stopped because the heater temperature drops more than 10 C.
    Later attempts failed, with increased M570 P and T parameters, because the printer time out after 999 seconds (with unspecified heater…:-O ).
    The strange thing now is the heater temperature are stable close to 250 C when I'm printer ABS.... but I don't care to found the main reason or faults behind the earlier temperate drops, because the printer works perfect now 🙂
    Thanks DC42 !


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