This test print is a little better...

2016-05-13 09.50.24.jpg
I find several type of 2 color dual extrusion objects. Side by side stuff (embedded) and overlapping.

I use two different types of nozzles, one very pointy and one flat.

Questions:
I set my steps per unit to 660... I find a flow rate of 80% in Cura (not from printer) works well.

- Should I remove nozzle, set to extrude 300mm, measure and repeat until it is exactly 300 mm?

Or, should I calculate 80% of the cross sectional area by length (volume) and use THAT as length?

- Different filaments PET-G, verses pure PLA, verses other PLA have different flow
rates at different temperature/pressure extrusions. Noticably so... I use flow rate
on the printer to correct (that affects RETRACTION!!!)

A) Is there a formulae for setting temperature / flow rate?

B) Does one switch to hardware retraction or just overkill it in cura so lowering the flow rate won't leave filament too close to the nozzle causing more ooze?

- Changing 660 steps per mm unit to 614 decreases or increases the amount of filament extruded?


Code:
// GDD // Explanations are here: http://reprap.org/wiki/Triffid_Hunte...ibration_Guide
    // GDD //----------------------------------------------------------My Settings ---------------------------------------------------------------------------------------
    // GDD // NEMA 17 with standard pitch M8 threaded rod:
    // GDD //(200 * 16) / 1.25 = 2560
    // GDD // NEMA 17 with SAE 5/16" threaded rod. It has 18 threads per inch (25.4mm / 18):
    // GDD //(200 16) / (25.4 / 18) = 2267.7165355
    // GDD // E-Steps: small_gear (motor) drives big_gear turns hob_bolt friction pushes filement.
    // GDD // e_steps_per_mm = (motor_steps_per_rev driver_microstep) (big_gear_teeth / small_gear_teeth) / (hob_effective_diameter pi)
    // GDD = (200steps/rev x 16microsteps) * (80teeth / 20teeth) / (6.325 mm * 3.14159) = 644.2
    // GDD James Clough (Manufacturer of hob gear & Itty Bitty Flex Extruder) suggests starting at 615


    // default settings

    #define DEFAULT_AXIS_STEPS_PER_UNIT   {80,80,2560,660.0}