Quote:

The Cube firmware uses 8 as the diameter of the "gear" when in actuality the OD is 9.5 with

a tooth depth of .45 makes the ID 8.6. The circumference varies from 29.83 for the 9.5 OD

to 27.04 for the ID 8.6. Therefore, the extruder INPUT length is 29.83-27.04mm per revolution regardless

of the number of steps. Neither of these would work very well because they are the extremes.

BFB Gcode M108 Sxx.x specifies the number of RPMsx10 of the extruder. So, one parameter is in TIME, RPM

and the other is DISTANCE, mm/step. Things can get confusing.

As an example M108 S29 = 2.9 RPMs.

Using a median circumference of 28.435mm*2.9RPM = 82.4615mm/minute or 1.3744mm/sec.

Using the median circumference of 28.435mm per revolution/200 steps per rev = 0.142175mm per step.

Or, expressed as steps/mm = 7.03358537014243 steps. Very unyielding.

Specifying RPM instead step/mm results in a fixed length of filament per minute regardless of the number of steps.

BTW, beautiful work on ur Mods. You continue to impress me !!!

G70

Thank you so much! I will try to use this parameters for the extrusion. Do you know the parameters for the XYZ movement as well? Number of steps per mm?