24 Volt Prometheus Hot End only reaching half power

  • Hello everyone,
    I’m new to the forum and the Duet WIFI but not 3d printing. I have a few questions on the set up if you wouldn’t mind? Here is my set up for a core XY.

    1. Duet WIFI version 1.02 hardware and 1.18.1 firmware
    2. 7" Panel Due
    3. 24 volt Prometheus hot end (including fans, heater and 100K Semitec 104GT2 NTC thermistor)
    4. Prometheus Extruder set up
    5. 24 volt dedicated power supply 20 amps and 500 watts
    6. 3 x Nema 17 Stepper Motor Bipolar 2A 59Ncm(84oz.in)
    7. 300x300 heated bed (not installed)

    Initial set up was a breeze no issues at all. Steppers and extruder running and scaled, now comes the problem the hot end is about a third/half of the desired temp ie if I set 150C i get about 85C. However the temp on the panel due and on the web page says 150C, at room temperature it gives me 23C (that’s about right give or take 2C). To me it looks like the voltage is halved, however I can’t find a parameter that regulates this (the thermistor is correct at 100k and the R value is right at 4700k) how does it know if its 12 volts or 24 volts?. I have ordered a 12 Volt heater for comparison.
    Any thoughts, hints or anyone experienced this? I have checked the forum but can't seem to find anyone with this issue. Sorry originally posted in the wrong place
    Thanks in advance Mark in Detroit

  • How are you checking the actual hotend temperature?

  • I'm using a laser thermometer directly on the tip and also on the heater, I questioned myself on that then powered up my modified Rostock Max V2 the readings are correct, unfortunately.

  • I have a laser temp sensor and could never get an accurate reading.

  • Have you tried setting the temperature and extrude?
    Also please attach your config.g

  • Jackal,
    I'll try to extrude again tomorrow had some issues tonight tried to upgrade to version 1.19 but ran into problems so took me some time to recover. Whenever I have tried in the past I doesn't do anything except make the extruder slip, ill recheck my config.g file and my override file and post them tomorrow. Thx for the help

  • Number40fan,
    I agree but in the same room over a 60C difference between to hot ends on the same laser? doesn't seem realistic for it to be a laser issue, more of user input in the parameters somewhere. Thx for the he help

  • administrators

    When you say a laser temp sensor I presume it is an IR thermometer with a laser sight. You cannot read the hot end temperature with an IR thermometer. If you want to check the temperature against the reading given by the Duet, insert a thermocouple probe into the hot end in place of the filament.

    Are you able to extrude PLA with the temperature set to 205C?

    What parameters do you have in your M305 P1 command in config.g?

  • Gentlemen,
    thanks for all the help I actually found the problem today after using a thermocouple purely on the hot end and heater. The problem was the new all-metal hot end (well new to me). The Bowden tube actually feeds about 30mm into the hot end and touches the nozzle in the cold area, the nozzle is about 44mm for configuration purposes. I had a gap of approx. 3mm that caused the filament to snare, ran the heater at 220 with PLA and it worked perfectly (I still need to set up room temp settings I'm about 2C off).
    I still cant understand why the thermometer actually gives decent readings on the Rostock and not the Prometheus but for future reference it now in the trash, DC42 thanks for pointing that out my shortcomings. Also DC42 my parameters for 305 are just standard until I tune it in properly ( M305 P0 T100000 B4388 R4700 H30 L0 ) I'm still in build faze.

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