1. Got a question or need help troubleshooting? Post to the troubleshooting forum or Search the forums!

Solved Extruder Calibration Issue

Discussion in 'Troubleshooting' started by Toro1966, Jan 23, 2017.

Thread Status:
Not open for further replies.
  1. Toro1966

    Toro1966 Active Member

    Joined:
    Jun 23, 2016
    Messages:
    398
    Likes Received:
    78
    Hey guys - went to recalibrate the extruder today and I'm having some issues. No matter what I set the esteps to, I am still underextruding (85 instead of 100mm). It's pretty consistent in its underextrusion, but no matter what I do, it won't extrude the full 100/100.

    I have checked the following:
    1 - All parts are tight - but not overtight. I have even tightened and loosened the hobb bolt just to make sure. No change in symptoms.
    2 - Adjusted tension on filament (two adjusting screws). Both tighten and loosened. No change in symptoms.
    3 - Tried different filaments. No change in symptoms.
    4 - Verified no clogs at all in nozzle. Cold pulls come out perfectly formed and clean shaped.
    5 - Sent M502/M500 commands to ensure the esteps I am increasing are being taken by the printer.

    The only thing that changes the amount of extrusion at all is the temperature. I generally print at 188. It is at this temp that I am calibrating. If I raise the temp to about 195-200, it will extrude the correct amount (100). I don't want to print at that temp, however, because the filament prints better at 188.

    I have thought about just adjusting my extrusion multiplier up to compensate at 188, but this is not making sense why changing the esteps will not change the amount extruded.
     
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    Did you flush the EEPROM and reload?


    ==== EEPROM GCodes ====

    M500 Store current settings in EEPROM for the next startup or M501.
    M501 Read all parameters from EEPROM. (Or, undo changes.)
    M502 Reset current settings to defaults, as set in Configurations.h. (Follow with M500 to reset the EEPROM too.)
    So after firmware is fixed you need the M502 and an M500 at some point for them to work.
     
  3. Toro1966

    Toro1966 Active Member

    Joined:
    Jun 23, 2016
    Messages:
    398
    Likes Received:
    78
  4. Toro1966

    Toro1966 Active Member

    Joined:
    Jun 23, 2016
    Messages:
    398
    Likes Received:
    78
    I even can see on the LCD what value is in the printer.
     
  5. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    OK, then ... the filament is not melting and flowing correctly at the temperature you are printing it at :)

    While you are not getting a full-on cold extrusion, you are under extruding.

    That is rare, I have not been able to reproduce this... but I can see where it would be easier with certain filament types
     
  6. Toro1966

    Toro1966 Active Member

    Joined:
    Jun 23, 2016
    Messages:
    398
    Likes Received:
    78
    Thanks Mark - any thoughts on corrective measures? Just print at a higher temp? I can do that of course, I just get concerned about stringing. The other weird thing is that even though I know it is underextruding by about 15%, my prints do not really reflect that. They are not brittle and seem to have good adhesion between layers.
     
  7. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    Well, about all I can suggest is to bump the temperature to the minimum you need for correct extrusion and then start playing with retraction to minimize the stringing.
     
  8. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
    Staff Member

    Joined:
    Feb 18, 2015
    Messages:
    5,905
    Likes Received:
    3,593
    It is harder to determine the exact eSteps number when there is no back pressure, everything else seems to affect it to a greater extent.

    If you are forced to print at a higher temp just compensate by increasing the print speed. The side benefit is that your stuff will print faster.
     
    mark tomlinson likes this.
  9. Toro1966

    Toro1966 Active Member

    Joined:
    Jun 23, 2016
    Messages:
    398
    Likes Received:
    78
    That's unfortunately what I was thinking. Thanks for the quick help.
     
  10. Toro1966

    Toro1966 Active Member

    Joined:
    Jun 23, 2016
    Messages:
    398
    Likes Received:
    78
    Thanks Waldo - we must have posted at the same time. Just saw your response. Appreciate it.
     
  11. Toro1966

    Toro1966 Active Member

    Joined:
    Jun 23, 2016
    Messages:
    398
    Likes Received:
    78
    What's amazing is if I bump it up to 195 it extrudes perfectly. I've already ran autotune as well....
     
  12. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    The exact temperature for perfect extrusion is not an exact science :)
    By that I mean that every batch of plastic is (or can be) slightly different.
     
  13. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
    Staff Member

    Joined:
    Feb 18, 2015
    Messages:
    5,905
    Likes Received:
    3,593
    Just for grins, I started increasing the temps on my PLA prints to get superior intra-layer adhesion and the stringing was there, although not bad. So I slowly kept increasing the print speed and the stringing went away. I now print all my PLA at 210°C
     
    mark tomlinson likes this.
Thread Status:
Not open for further replies.

Share This Page