Calibrate extruder stepper motor



  • Hi,

    I have read, and follow the guide to calibrate de steps in extruder motor… but i am no convinced.

    the method i have follow is this: https://reprappro.com/documentation/commissioning-introduction/calibration-duet/#X_Y_and_Z_axis_calibration

    This idea… what mistakes have....

    1 - My printer, a TLM, uses a Nema17 Stepper motor in extruder, with a Step of 1,8º
    2 - Think, i am not sure, i have to check, the extruder have a gear to drag de filament of external diam. 12mm
    3 - If external diam=12 mm, the perimeter is Per=2xPIXr, in this case Per=2 x Pi x 6 mm = 37.69 mm
    4 - If 1 step is 1,8º --> 360º / 1,8 = 200 steps for revolution
    5 - 1 revolution -->360º --> 200 steps --> 37.69 mm: 1 step advance --> (37.69/200) = 0,1884 extruded filament

    In gcode, E92, you adjusts the steps .... but ,

    A)- What are you adjusting? The steps in M92... what represent, 1 mm (notes in config.g, say that)? in teory, no. Why think this, i have this E92, in my config.g

    [[language]]
    M92 X160 Y160 Z160 E837 ; Set steps per mm
    
    

    If the theory show up its true, I suspect that no. When stepper motor, runs 837 steps, it would have to extrude: 837 x 0,1884 = 157,6908…. and NO. The theory its WRONG.

    What are the correct maths?
    I could light up someone?

    Thanks



  • Check out this guide - http://reprap.org/wiki/Triffid_Hunter%27s_Calibration_Guide#Measure

    Basically I'd disconnect your hot end, cut the filament flush with the extruder and extrude 100mm of filament not faster than 5mm/s and then measure what you get, You can then adjust the steps with this equation.

    G91 ;relative movement
    G1 E100 F300 ; extrude 100mm at 5mm/s

    new_e_steps = old_e_steps * (100 / distance_actually_moved)



  • What you've linked to seems to be a way to load the filament so I can see why you are confused. There are better guides such as this one http://reprap.org/wiki/Triffid_Hunter%27s_Calibration_Guide. Or simply put "Calibrating a 3D printer extruder" orr some such into your favourite search engine.

    Edit. Typing at the same time as DADIY (funny how we both chose the same guide).


 

Looks like your connection to Duet3D was lost, please wait while we try to reconnect.