Heater Fault - Using old style E3D v6 hotend



  • I've recently had to replace the heater block due to a nozzle shearing in the new style one. Due to cost I'm now using the old style, with a 100K ohm thermistor rather than a thermistor cartridge.

    Due to connection issues (probably duff ethernet on the Duet 0.8.5, different thread) I'm using pronterface, but now get the following whenever I try to heat the hotend:

    Setting hotend temperature to 210.000000 degrees Celsius.
    Error: heating fault on heater 1, temperature rising much more slowly than the expected 1.4°C/sec
    [ERROR] Error: heating fault on heater 1, temperature rising much more slowly than the expected 1.4°C/sec

    Thoguhts? Suggestions on how to fix it? I've tried reflashing firmware, no obvious effect….

    EDIT: Forgot to mention that the temperature seems to be rising fine, goes from room temp (~15 C) to 60 in significantly less than the 30 seconds maths seems to require....



  • Have you re tuned your heater? - See this wiki entry - https://duet3d.com/wiki/Tuning_the_heater_temperature_control



  • Just ran it, got:
    Auto tune cancelled because target temperature was not reached.

    Heater got up to 210, target was the 240 from the wiki page. is it worth trying "M303 H1 S210" as that was reached?


  • administrators

    Which firmware version are you using?



  • RepRapFirmware-1.19



  • I had the same thing happen to me with me during a recent autotune. I ended up adding a p1.0 in the m303 command and had no more issues. example M303 H1 P1.0 S240

    I'm running Duetwifi with 1.19 firmware.



  • Tried M303 H1 P1.0 S240 - got to 211 then timed out. I'm wondering if the replacement blocks are made from a less heat conductive material? Then I'd need to increase the time allowed? Plausible?



  • @TinkerBill:

    ….....................I'm wondering if the replacement blocks are made from a less heat conductive material? ............... Plausible?

    More than possible if the blocks are, shall we say clones of oriental origin. I once tried to help someone who had similar problems with a Diamond hot end clone. It turned out that instead of being made from brass, the hot end was made from brass plated steel of some sort. Brass has a thermal conductivity of about 120 Watts\Kelvin Metre and steel about 45, hence the problem. Aluminium is better than both at about 235.



  • Ok… so on the assumption that it's taking longer due to me being broke/cheap rather than a fault (as it is heating up, just not quickly) what do I change? I would guess "M570 S180" as the description states it is basically defining how long the hot end can take?



  • Before we get on to that, can you check your M143 in config.g to see what the limit is set to. You should have something like M143 Snnn. If nnn is set to 210, that would explain why it times out at 210 deg C.



  • M143 is set to 290


  • administrators

    It sounds to me that the heater is under-powered. Might you be using a 24V heater cartridge on a 12V system?



  • @dc42:

    It sounds to me that the heater is under-powered. Might you be using a 24V heater cartridge on a 12V system?

    The heater and power supply are both 12v



  • One final thing to check. As you've changed the thermistor, have you got the correct values in M305 for that new thermistor? The only other possibility that I can think of is that it might be the cartridge itself. Do you have another that you can try?

    You could try setting a lower target temperature but it's a bit like having a warning light appear on the dashboard of your car, and putting a bit of tape over it. It hides the warning but the underlying problem is still there.



  • Well the new thermistor is 100k ohm, same as the thermistor cartridge. Also, the ir thermometer I have says it's accurate to within 5 degrees, so probably just tolerance difference.



  • My config file doesn't have a M307 line, are the values on http://reprap.org/wiki/G-code#M307:_Set_or_report_heating_process_parameters worth using?

    Sorry if these are dumb questions - not much software experience…



  • I'm not sure what default values duet uses but they should be "good enough". Run M307 without any parameters and it will report what is in use. If the gain (the "A" value) is low, you could try setting it higher.



  • I sent a M307, didn't get anything back… Probably the problem then?



  • Sorry my bad. You need to add the heater number. H0 is the bed and H1 is the first hot end, so M307 H1 should report what's in use.



  • Should have tried that myself, no worries.

    SENDING:M307 H1
    Heater 1 model: gain 340.0, time constant 140.0, dead time 5.5, max PWM 1.00, mode: PID
    Computed PID parameters for setpoint change: P13.4, I0.095, D51.4
    Computed PID parameters for load change: P13.4, I0.949, D51.4

    Is there anything wrong here? Reaally don't know what I'm looking for 😕



  • Those number don't look far out IMO - not enough to cause the problems you are having. Everything is pointing to your heater block as that's the only other thing you have changed and it's after that change that things went awry. It's possible that you have a "lazy" heater cartridge. Do you have spare you can try? One other thing, can you hands on any copper grease? If you coat the heater cartridge in that, it will help thermal transfer between the cartridge and the block. Just a thought…..



  • I've not got a spare heater cartridge, will try the copper grease. If that doesn't work, what bodge could I do to just stop the software worrying about the time taken to heat up? Rather not order another new heater cartridge…. (again I'm cheap/broke)



  • @TinkerBill:

    If that doesn't work, what bodge could I do to just stop the software worrying about the time taken to heat up?

    Like I said, that would be like putting a bit of sticky tape over a warning light on your car dashboard. It will hide the warning light but the problem still exists. You could for example send M302 to enable cold extrude but it still won't print.



  • So there's no way of changing the expected rate of heat increase? I can't tell the printer I expect it to rise by at least 0.5 deg/s instead of 1.7?



  • @TinkerBill:

    So there's no way of changing the expected rate of heat increase? I can't tell the printer I expect it to rise by at least 0.5 deg/s instead of 1.7?

    I don't know of one personally. You could try increasing the heater fault detection time and or temperature excursion limits -see here https://duet3d.com/wiki/G-code#M570:_Configure_heater_fault_detection. That may allow you to print in some sort of fashion. I think (but I'm not sure) that you would still see an error if you tried to tune the heater).


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