Temperature Drop

Discussion in 'E3D-v6 and Lite6' started by ktoth, Aug 10, 2015.

  1. ktoth

    ktoth Member

    Joined:
    Aug 10, 2015
    Messages:
    3
    Likes Received:
    0
    I've been having trouble maintaining print temp with my e3d hot end... quite honestly I've never had much success with it. I got off two or three calibration prints before I started having a jamming issue (eventually corrected by chamfering the corners of the bowden tube) and I have since had trouble getting the hot end up to print temp (240). It takes about 20-30 minutes and then immediately starts dropping in temp to below 200 degrees.

    I'm not sure if this is a hardware (wiring) software (firmware) or user error (fan comes on) issue... I've tried everything and I'm ready to give up. I've replaced about 4 semitec thermistors before I got fed up and bought a screw in type... I've run PID autotune to 240. One of the other posts suggested that my heater block was screwed in to tight, so I loosened it a little and now I can get it to maintain 205... but its still below my recommended print settings.

    Any troubleshooting help would be greatly appreciated.
     
  2. elmoret

    elmoret Administrator

    Joined:
    Mar 1, 2014
    Messages:
    586
    Likes Received:
    91
    It sounds like the hotend is assembled improperly. Is there a ~3mm gap between the heatsink and hotend? Do you have a fan blowing on the heaterblock? Can you post a few photos of your setup?

    Also how are you breaking thermistors? I have over 1000 prints on my original Semitec 104GT2. Haven't ever broken a thermistor actually, with about 20 swaps between Lite6 and v6.
     
  3. ktoth

    ktoth Member

    Joined:
    Aug 10, 2015
    Messages:
    3
    Likes Received:
    0
    I broke the thermistors because my hands are big and clumsy and the leads are the width of a human hair. I broke the first one dissassembling the hot end to clear a jam from the heat break. I broke the next one because I thought it was faulty and I tore it in half when trying to seperate it from the 18 gauge wires that connect it to the rambo. I broke my spare trying to fit the insulation sheath over the leads during installation.

    The layer fan is a nuisance, but not the root problem. It kept coming on even when I disabled it, till I realized that I had set my minimum fan speed to 100% in matter control settings.... I'm sure my problem is somewhere in the eeprom or firmware settings because the temp drops down to 195 ish and than gradually returns to about 220 after 15-20 minutes print time.

    Another potential issue may be the seating of the cooling fan shroud causing too much air circulation around the block?
     
  4. TRN

    TRN New Member

    Joined:
    Sep 11, 2015
    Messages:
    1
    Likes Received:
    0
    Ktoth, a picture might help us understand(might not).
    I've got a question, what's the ambient temperature like where you keep the printer, and is there significant air movement around your printer? Either one could be a problem. Did it go up to the target temperature before you replaced the thermistor with a different type? I've had my matter control temps mis-set, so that when I took it off preheat it started dropping, that might be a possible source of your problem. You might also need to change the thermistor setting in your firmware if you haven't yet.
    What's the target temp say on the front LCD? Just as a double check the controller is aiming for the right temp.
     
  5. Jason_WI

    Jason_WI Member

    Joined:
    Aug 24, 2014
    Messages:
    5
    Likes Received:
    0
    If you are using Marlin firmware set your PID BANG_MAX to at least 180 in configuration.h Anything lower and you will have slow and lagging heat response.
     

Share This Page