Extruder calibration

  • I read a lot of guide on internet regarding the extruder calibration .
    I found some guides on internet that suggest to make measurement with the filament running through the hotend , other state that is sufficient measure the filament extruded from the extruder even if non mounted on the printer.

    Also If I extrude 100 mm i obtain
    99,58 mm with 401 microstep
    100,5 mm with 402 microstep
    Are acceptable measures both?

  • Both acceptable but I'm curious to know how you managed to mark and measure the filament to an accuracy of 0.02mm over 100mm in length.

  • I used a digital caliper. I know that at max I have an accuracy of 0,1
    I didn't marked the filament I cut it at emergence of the bowden.

    Can we use decimal measures? example 401,5 microsteps?

  • Yes you can. It sounds odd to do so, but the firmware multiplies the steps/mm by the amount of filament required for a move and moves the whole number of steps closest to that number. So 401.5 is going to move it occasionally one step more than 401.

    Plus when you consider from one reel to the next, and within one reel, filament diameter can vary 10% its not hard to see that until someone cracks a really good filament sensor which can measure filament in 3 dimensions and feedback to the controller, if you get it to within 0.5mm of 100mm and then trim the flow rate during the first layer you'll be there (provided your first layer height is reliably the same each print). Come to think of it setting "print objects sequentially" would allow a small test cube to be printed before moving on to the main event, as a tool to getting the hang of it. After a while you learn to eyeball it and adjust flow, then go back to your slicer and change the extrusion multiplier by that amount for the next print (remembering to return flow to 100).

Log in to reply