Extrusion multipliers for 2.85mm filament

[dennisjm]

I think some of the quality issues I"ve faced have to do with over extruding. So today I've been trying to get a good extrusion multiplier for some plastic and print some tests. I keep going lower and lower. For my 1.75mm filament I've always used in the .9-1.0 range depending on the material. For the 2.85 stuff I have I'm going much much lower and I almost think I could still go lower. Something seems a little fishy that the calculations for plastic would be 30% off. I just printed a perfect flat bottom several layers with no gaps at a .65 multiplier for filament measured at 2.94mm.

Attaching factory.. maybe you can see something. That seems screwy to me though.

aw3d_calibration.factory

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[AndersE]

Have you calibrated your extrudermotor steps/mm (with extrusion set at 1.0)?
I think "most" printers are off on that.

If you have you "should" not need to change extrusion multiplier (set to 1).

What printer do you have? I have read that solodoodles over-extrudes factory set.
My own K8200 did also over-extrude factory set.

A good guide here: http://reprap.org/wiki/Triffid_Hunter%2 ... tion_Guide

[dennisjm]

Well I didn't do anything with extrusion steps. I'm using the stock Airwolf HD2X firmware, stock profile and just starting from there to try to get things printing. I just printed a bunch of parts with the multiplier set at .72 and they worked pretty well though.

Also, steps/mm is only something used on the x3g generation. The hd2x is Marlin based firmware that directly consumes gcode.

[AndersE]

Don't know what you mean with "directly consume g-code".

K8200 is also a marlin based machine.

[dennisjm]

Don't know what you mean with "directly consume g-code".

K8200 is also a marlin based machine.

I mean that the printer prints gcode files directly. It doesn't print x3g files.

[AndersE]

I dont think that that means anything, all printers use g-code the x3g is probably just a "codec" so to speak so you can't run any slicer you want without it supported.

The steps/mm is set in the firmware.

[dennisjm]

There is also a steps/mm set on the x3g generation tab under firmware configuration.

I'll check in the firmware and see if I can find out what it's set to and what it should be set to. I know at one point I had to do a firmware upgrade because the temperature settings became all messed up.

[AndersE]

Do that. And read the link i posted earlier. There are other guides also. Just search for "extrusion multiplier calibration".
If you haven't, also calibrate x,y and z steppers to get all printed sizes correct..

[dennisjm]

I shouldn't technically have to do any of this as this all pre-configured from AW3D. Not that I'm saying they got it right. I can vouch that parts are dimensionally accurate though. I'm printing some fairly tight tolerances on a number of parts and haven't had any issues.

[dsegel]

Marlin extruder steps are set with the M92 command, like ' M92 X80.00 Y80.00 Z2020.00 E94.50'. The value you use for the E value will depend on the drive system and gearing you use. For example, the value I listed is for a Printrbot direct drive extruder.