ProfileMaker thoughts…

Looking at Dave’s Profileinator seems really well suited to a stepper extruder.  However, he also suggests adding a “Flow Fudge Factor.”  I just use this set to 1.0, so I’m not sure if I’m using it correctly.

Flow Fudge Factor: I have to enter 1.0 into the flow rate to get 2.0 RPMs on the extruder.. I got tired of doing this math so I added flow fudge factor and set it to 0.5. This doesn’t change the volume calculations – it just modifies the flow rate on the table. If you have a MK4/MK5 extruder with a DC motor, start this at 127.5 to get the PWM value to use

In any case, it looks like by multiplying it by 127.5 you can get the required flowrate for a DC motor.  In printing with a DC motor, I never wanted to drop the speed below 255, because the DC motor had such a small range of speeds.  I could print between about 230 – 255.  Given this, I can understand why so many others, probably using a DC motor, would rather pick their flowrate as 255 and then determine the proper feedrates.

Skeinforge calibration test 1, 2

Test 1, Test 2

Test 1, Test 2

For these tests I used the “single walled test piece” from Da3v

  1. Test 1 on the left
    1. Temperature: 220
    2. Skeinforge -> Carve -> Layer Thickness (mm): 0.36
    3. Skeinforge -> Speed -> Flowrate PWM Setting (if PWM Setting is Chosen): 230
    4. Skeinforge -> Speed -> Feedrate (mm/s): 40
    5. Skeinforge -> Speed -> Travel Feedrate (mm/s): 40
    6. Extrusion diameter: 0.57
    7. Skeinforge -> Speed -> Extrusion Diameter Over Thickness (ratio): 1.583
    8. Wall thickness of the test piece: 0.40
  2. Test 2 on the right
    1. Skeinforge -> Speed -> Feedrate (mm/s): 30
    2. Skeinforge -> Speed -> Travel Feedrate (mm/s): 30
    3. Wall thickness of the test piece: 0.40
    4. Skeinforge -> Speed -> Extrusion Diameter Over Thickness (ratio): 1.583
    5. Skeinforge -> Carve -> Extrusion Width over Thickness (ratio): 1.583
    6. Skeinforge -> Inset -> Extrusion Perimeter Width over Thickness (ratio): 1.583

That’s a pretty big improvement.  I haven’t tried printing something small with lots of details, but now I’m curious how well these settings hold up.  My previous settings (which I zipped in case I totally messed this up) were reasonably good, but the layer adhesion was merely adequate.