Commissioning
Calibrating the Extruder
In the motherboard firmware, you must edit the configuration.h file in order to have your RepRap/RepStrap working correctly.
- (if you only see a configuration.h.dist, copy it to configuration.h)
E_STEPS_PER_MM
This is set to 0.706 which is the 5mm splined shaft, with no gearbox, on a motor with a 1.8 degree step, and 3mm filament. If this is what you are using, change nothing. However if this is not the case you will need to make some measurements and jot them down. (0.743 is the value for the above with a 3/16" splined shaft).
- Filament Diameter
- Nozzle Diameter
- Pinch Wheel Diameter
- Steps of stepper
Adrian B. used the formula:
<math>\frac{1}{\frac{\pi\varnothing_{pw}}{Steps_{360}}.Ratio_{Nozzle to Filament}}</math>
Where as in the recent blog post the formula is
<math>\frac{\varnothing _{Nozzle}^2 . Steps_{360}.Ratio_{gearbox}}{\varnothing _{Filament}^2. \pi . \varnothing_{pw}}</math>
Both of which are confusing, so Grogyan came up with
<math>(\frac{Steps_{360} . Ratio_{gearbox}} { \pi . \varnothing_{pw}}) . (\frac{\varnothing _{Nozzle}}{ \varnothing_{Filament}})^2</math>
Essentially what is happening is having the ratio of filament and nozzle squared, multiplied by the arc of one step of the stepper motor.
Note to self add a method of putting values on this page and output the correct value.
Personal thanks to for enabling formulas to be put into wiki's
sitmo for their equation editor
Formula Help for the correct syntax
