Inconsistent Extrusion

Discussion in 'Calibration, Help, and Troubleshooting' started by Springfield-Jack, Mar 4, 2016.

  1. Springfield-Jack

    Springfield-Jack Well-Known Member

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    When calibrating E-steps I am getting Inconsistent Extrusion!I thought I had pinned it down to a loose hobbed bolt, but after fixing that, extrusion is still wildly variable.Anybody have any suggestions as to what I should be looking for?
     
    #1 Springfield-Jack, Mar 4, 2016
    Last edited: Mar 4, 2016
  2. Mike Kelly

    Mike Kelly Volunteer

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    Might be the case of a stepper driver over heating, or being under currented.

    Take off the extruder or hot end so you're not feeding into the melt zone. Then try gripping the filament as it enters into the extruder and try preventing it from feeding in. Increase the current on the stepper driver if you can stop it very easily.

    If increasing the current causes it to overheat it may be a bad stepper driver
     
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  3. Springfield-Jack

    Springfield-Jack Well-Known Member

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    Thanks for the help.I can't stop the filament feeding in -so it's not under powered.As an experiment I switched to the second extruder. having made sure they were set at the same current and this one was also inconsistent- not quite as bad as the first-there was some repeatability but still varied considerably in the extruded length.Both drivers run hot, too hot to keep a finger on -is this normal?What is the likelihood of having two defective drivers?
     
    #3 Springfield-Jack, Mar 4, 2016
    Last edited: Mar 4, 2016
  4. Mike Kelly

    Mike Kelly Volunteer

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    What voltages are you running at? I'm not sure what the likelyhood is but I had a bad stepper driver. It shouldn't get so hot you can't keep your finger on it, especially at a reasonable voltage.
     
  5. Springfield-Jack

    Springfield-Jack Well-Known Member

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    0.58v should I turn them down?
     
  6. Mike Kelly

    Mike Kelly Volunteer

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    No that's adequate. Sounds to me like all symptoms point to overheating from faulty stepper driver.

    Fan above them doesn't help?
     
  7. Springfield-Jack

    Springfield-Jack Well-Known Member

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    Moving the fan directly above the driver increases consistency considerably-still the occasional error-but I think it confirms your diagnosis.Time to get new drivers(with heatsinks) and an additional fan.Thanks again for the help.
     
  8. Mike Kelly

    Mike Kelly Volunteer

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    I think they're also running a 24v fan on a 12v output, at least for dual. That would reduce cooling capacity as well, but much quieter
     

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