New option "Calibrate E" in firmware 3.0.10-alpha2  

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

hi patrizio.b
can you explain the 10cm extrusion trick ?

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

The 10cm calibration trick:

You choose a spot on your filament about 15cm from the top of your extruder, and make a mark with a sharpie. Be sure to measure exactly the distance from your mark to the top of your extruder.

Then you go into your favorite slicer or pronterface, and send a command to the extruder (remember to preheat) asking it to extrude 100mm.
When it's done, you measure again the distance from your mark to the top of the extruder.. If the extruder is calibrated right (and your settings for the filament is correct, ie. diameter etc.) you will have extruded exactly 100mm of filament.

If it's off, you can calibrate by adjusting the settings in the firmware accordingly.

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

Where can I download this alpha release?

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

as you can see by the version number, the release is still in alpha status. acatually it's neither officially released nor will you find the *.hex file for download here.
but, at your own risk, you can download the source files from the git repository and build/compile them yourself. 😕
the result could be either this 🙄 or that 😥 .

to do so, you have to set up a proper arduino 1.6.8 IDE with the correct boards and libraries installed and no interfering with other arduino installations.
thanks to allen.d, that's no longer a pita.
💡

@klaus: thanks for the explanation ! until now i didn't notice that there is a need for E-calibration. 😀

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

...
Then you go into your favorite slicer or pronterface, and send a command to the extruder (remember to preheat) asking it to extrude 100mm...
❓
can i invoke the same through the i3/mk2 menue: <settings> -> <move axis> -> <extruder> ?

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

Try it and see! 🙂
Joan

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

Try it and see! 🙂
Joan

ok my lady, i followed your advice 😎 .

and i encountered that a "+100" will push 93mm of filament through the nozzle.
so i guess i have to adjust something.

i think tomorrow i'll compile and flash the 3.0.10-alpha2.
or are there other simple ways to correct that value ?

btw: wouldn't it be necessary to do that adjustment for all the different types of filament at the shelf, or is the friction for the different materials nearly the same as long as the extruders drive gear doesn't slip ?.

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

I haven't studied the dynamics of filament management, however I would expect similar delivery rates for all filaments as long as the hobbed gear doesn't slip.
I expect a hard filament would extrude marginally greater length because the drive is provided by the tips of the hobbed wheel teeth, whilst a softer filament, may allow the teeth to sink into the material, resulting in a little more surface deformation and an effectively smaller diameter drive mechanism. but I suspect that the difference would be minimal.

Regards Joan

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

Try it and see! 🙂
Joan

ok my lady, i followed your advice 😎 .

and i encountered that a "+100" will push 93mm of filament through the nozzle.
so i guess i have to adjust something.

i think tomorrow i'll compile and flash the 3.0.10-alpha2.
or are there other simple ways to correct that value ?

btw: wouldn't it be necessary to do that adjustment for all the different types of filament at the shelf, or is the friction for the different materials nearly the same as long as the extruders drive gear doesn't slip ?.

i have devised a method that may or may not be accurate, but it seems to work for me.

I mark the filament, then use the knob on the LCD controller to extrude 100mm (Settings>Move axis>Extruder), then measure actual extrusion. Like you, I find around 94-95mm actual extrusion for most filaments.

Then, I calculate how much more should be extruded: 100mm / 94mm = 1.0638

Then I create a custom filament setting in Slic3r for that particular filament, setting the 'Extrusion multiplier' to 1.0638 .

I try to give the Filament settings descriptive names, like: Polymaker-PC-Plus_EM1.053_270-120_NoFan_2016-12-26

I am glad you are looking into this, I have mentioned this method a few times before in this forum, but no-one seemed very interested in it. Either they just ignore filament calibration, or they are using Pronterface or whatever to write some code to achieve calibration. i am however at this stage mostly interested in any technique that can be accomplished without a USB cable, PC, or anything other than the one knob on the LCD control unit.

It could be that I am getting good results simply because there is a lot of tolerance in the system, or my tweak has no real effect. I have not systematically tested it. But, I get good results, and, so far, no-one has replied with any theoretical or tested objections to this method.

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

I've used the exact method MrMik described, and it's worked very well for me. I've needed an Extrusion multiplier range of about 1.07 to 1.1 for the various filaments I've used so far.

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

I've used the exact method MrMik described, and it's worked very well for me. I've needed an Extrusion multiplier range of about 1.07 to 1.1 for the various filaments I've used so far.

Ah, good to hear!
Have you tried to print without the Extrusion Multiplier adjustment and the results were different?

I never tried that, I really should do it though. Maybe I'll print a series of Benchies with different extrusion multiplier settings and then I'll know if the EM=1.06 or thereabouts is really the best, or not.

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

I've used the exact method MrMik described, and it's worked very well for me. I've needed an Extrusion multiplier range of about 1.07 to 1.1 for the various filaments I've used so far.

Ah, good to hear!
Have you tried to print without the Extrusion Multiplier adjustment and the results were different?

I never tried that, I really should do it though. Maybe I'll print a series of Benchies with different extrusion multiplier settings and then I'll know if the EM=1.06 or thereabouts is really the best, or not.

I am VERY interested in your results and looking forward to what you find. I am fairly new to 3d printing and found this topic very interesting. But, as someone said, many seem to ignore this aspect. I understand why, I have not concerned myself with it and I am getting great prints. But the amateur scientist/perfectionist that I am makes me very intrigued to learn what you find out.

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

I confirmed with a systematic test that my method of extruder calibration without firmware programming works accurately.

I printed a series of Benchy's from PLA, with the only difference being the Extrusion Multiplier setting in the Slic3r Filament settings.

The Benchy printed with EM 1.075 is the best, and the further the EM value is changed in either direction, the worse the print gets.
EM 1.075 is the value I have chosen and used for several rolls of this filament already, after comparing actual extrusion to dialled-up extrusion of 100mm.

I learned a few things, for example that the silvery streaks through the printed purple material represent under-extrusion.

I printed Benchys with EMs of 0.900; 1.000 ; 1.050 ; 1.075 ; 1.100 ; and 1.150 .

So here it is again, how to calibrate the extruder using only the LCD control knob, a pen and a ruler:

I mark the filament, then use the knob on the LCD controller to extrude 100mm (Settings>Move axis>Extruder), then measure actual extrusion.
I find around 94-95mm actual extrusion for most filaments.

Then, I calculate how much more should be extruded: 100mm / 94mm = 1.0638

Then I create a custom filament setting in Slic3r for that particular filament, setting the 'Extrusion multiplier' to 1.0638 .

I try to give the Filament settings descriptive names, like: Polymaker-PC-Plus_EM1.053_2017-03-02

Re: New option "Calibrate E" in firmware 3.0.10-alpha2

Very interesting results, MrMik, and very conclusive. I haven't done such a test myself, but recently I accidentally printed with the extrusion multiplier set to 1.0 for a part which I needed very high dimensional accuracy. The resulting dimensions were not as accurate as when I used the correct multiplier.