Tuning Skeinforge

Skeinforge has *lots* of parameters to set and not much information on what they all do. To help me set my version up I found the following page very useful (although some of the parameters have changed name or no longer exist) Skeinforge Wiki.


In the end I went with the default parameters for PLA with the following changes.


Feed Rate = 40mm/s
Flow Rate = 57.6 
Retraction Speed = 250
Distance = 30mm
Extra = -10mm


The last 3 settings help with the blobbing that you get at the end of each thread by sucking the excess filament back into the nozzle by momentarily retracting the filament. I've found PLA to be very oozy. 


I found the best page to help me set up the feed rate and flow rate was this one from Tony @rapman3. Since I'm using a stepper based extruder the flow rate setting, which appears to be a PWM control value was a bit meaningless, however, I followed Tony's instructions to set up the deposited filament width to 0.72mm with a height of 0.4mm by varying the Flow Rate setting for the specified Feed Rate setting. By trial and error I found that the setting for a feed rate of 16mm/s (bed speed) required a flow rate of 23.

Final Test Print, 0.4mm Layer Height plus Warts

At 16mm/s, this printed too slowly and I know that the Mendel can print much faster, so I upped it to 40mm/s and found that the Flow Rate scaled in a near linear fashion. To test the various parameters, I used Tony's approach of printing a single filament walled object, a 3cm diameter, 1cm high cylinder. The end results were quite pleasing, except for the warts, which is the subject of a future investigation.