Extruder calibration help needed please. I was looking on Reprap development blog on calibrating the extruder and the information it has is a little different than what is in the Marlin firmware. The blog says that the number would be something like 700 steps per millimeter for the extruder but in the firmware it shows 760*1.1
I have a Wades extruder…does the 1.1 have something to do with the gear ratio? If so what would that number need to be? The gears that I have are a 10 tooth on the stepper motor and a 43 tooth on the hobbed bolt.
Using tooth count ratios might be an OK starting point for extruder calibration, but the irregular teeth on a hobbed bolt (I’m being kind here) and the way it interacts with different kinds of filament and different amounts of tension on the extruder idler will dictate using an empirical method that will work fine without any prelimary math. Try Triffid Hunter’s Calibration Guide.
Mike, I suggest using this method to calibrate your extruder initially: http://richrap.blogspot.com/2012/01/slic3r-is-nicer-part-1-settings-and.html
Stop when it says “Now you have a perfectly calibrated extruder, you are well on the way to perfect printing”
And then follow the ‘fine tuning’ section here: http://reprap.org/wiki/Triffid_Hunter’s_Calibration_Guide#E_Steps_Fine_Tuning
@ThantiK can you tell me what the 1.1 is after the steps per mm in the Marlin firmware…
#define DEFAULT_AXIS_STEPS_PER_UNIT {159.487,159.487,200.32832/1.25,7601.1}
Reason I ask is that I told the extruder to extrude 30mm and it only did 20.09 so doing the math the number in the firmware needs to be 1140 instead of the 760 that I started with. I just wanted to make sure I was doing it right. Also I have the stepper driver set at 1/32 micro stepping and I didn’t know if that has anything to do with the number
Yes, microstepping does have to deal with the steps per mm. You increase the microstepping and you DOUBLE the steps per mm it takes. Don’t worry about what you see as defaults in the firmware, those are for a different set of hardware, with different drivers than your machine, different setup, etc. That’s why it’s all editable. If you want to get rid of the *1.1, it doesn’t matter.
For example, if you have a single step go 1mm, and increase it to 1/2 stepping, it takes 2 steps to go the same distance. 1/4th takes 4 steps, 8th takes 8 steps, and so on until 1/32 takes 32 steps for what would have been the equivalent distance of a ‘single’ step.