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Fletch
(@fletch)
Active Member
setting esteps for extruder calibration

I know how to calibrate my extruder. What I don't understand is an easy way to store the calibrated esteps into the firmware. I have watched many videos on different ways to include it in g-code but it just seems like it would be better to input and store this directly in the firmware on the printer. One guy using a MakerFarm printer had this ability in his firmware and it looked super easy. Maybe the prusa firmware has something similar but I cannot find it.

Is there a way to do this?

Posted : 30/06/2017 4:31 am
cory.w
(@cory-w)
Estimable Member
Re: setting esteps for extruder calibration

Do you have a computer software to send custom GCodes?

All you need to do is:
M92 E(New Calibration Step #)
M500

Posted : 03/07/2017 3:22 am
TiccTech
(@ticctech)
Eminent Member
Re: setting esteps for extruder calibration

Note that in firmware 3.0.12, M500 no longer stores extruder steps per unit. 😯
Unless you have a multi-material printer, you may want to stick with 3.0.12-RC2 until this gets sorted out.

The 3.0.12 release note saysExtruder axis steps per unit excluded from M500:

M500 is gcode which serves for saving currently set parameters to EEPROM. If M500 is called, printer saves parameters such as max. feedrate, PID etc. to EEPROM and from this time saved parameters are used instead of default parameters.
M500 saves also axis steps per unit. For single material printer and multi material printer, different axis steps per unit values for extruder are needed. Using M500 (for example running PID tuning) with single material printer and then upgrading to multi material leads to faulty extruder behavior. Thus axis steps per unit for extruder were excluded from M500.
EEPROM version was not changed to achieve this, thus flashing 3.0.12 has no influence on other stored parameters such as PID calibration results.

Posted : 16/07/2017 10:23 pm
Barry
(@barry)
Active Member
Re: setting esteps for extruder calibration

On my MK2S, the factory default Extruder step count under extrudes by nearly 8%!

I've very carefully tuned this and my prints with v3.0.11 firmware have been very acceptable. Looks like I'm going to stay on that version until they fix this again.

This is not optional, it is required if you want any quality from your prints.

Posted : 26/07/2017 6:15 am
Robert Bonham
(@robert-bonham)
Estimable Member
Re: setting esteps for extruder calibration


On my MK2S, the factory default Extruder step count under extrudes by nearly 8%!

I've very carefully tuned this and my prints with v3.0.11 firmware have been very acceptable. Looks like I'm going to stay on that version until they fix this again.

This is not optional, it is required if you want any quality from your prints.

I much prefer having the M92 settings saved to firmware, but....
You can also and the M92 command to your start up gcode in your slicer or adjust the feed rate in you filament settings.

Robert B.

Posted : 26/07/2017 11:41 pm
PJR
 PJR
(@pjr)
Antient Member Moderator
Re: setting esteps for extruder calibration

I much prefer having the M92 settings saved to firmware, but....
You can also and the M92 command to your start up gcode in your slicer or adjust the feed rate in you filament settings.

It is better to have this setting in GCode, especially "Material GCode" as different filaments can require different values.

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…

Posted : 27/07/2017 2:18 pm
Barry
(@barry)
Active Member
Re: setting esteps for extruder calibration

I would think this calibration setting is specific to each printer. Dependant on the diameter of the extruder feed gear and the steps per revolution of the extruder servo.

Possibly harder or softer filament would feed through at a different 'radius' on the cogged feeder gear. So calibrating cold or hot might affect the results a small amount. Unloading filament would show roughly how much the size alters by the size of the extruder teeth marks in the filament.

The extruder gear has an effective feed radius of about 6.0 mm (plus half the filament diameter). Soft filament might reduce that radius by about 0.2 mm, or about 2.9%. Incidentally, my Estep is increased by 3.5% to calibrate with PLA.

Different filament types might feed through at a slightly different 'radius', again due to their hardness and how much they squeeze as they go through the extruder gear. I wouldn't expect this to vary by much.

I'd also think that the physical diameter of the filament might also affect this step count. Filament tolerance of +/- 0.03mm would make a different radius by 0.4%. I'd think that adding in the size correctly would compensate for this small amount.

So, I don't expect this number to change based on material, and is more dependant on the physical characteristics of the printer.

Posted : 31/07/2017 2:02 am
Ro Derrick
(@ro-derrick)
Active Member
Re: setting esteps for extruder calibration

I have the flex3drive installed and am trying to work out gcodes at startup.

I would very much like to have the 40:1 reduction hardcoded into the firmware (40x speed up) so things like filament change will work straught when powered up...

anyone ?

Posted : 22/08/2017 3:52 pm
Ro Derrick
(@ro-derrick)
Active Member
Re: setting esteps for extruder calibration

Also regarding the m500 command not storing steps , isn't that only for the MM firmware ?

In the firmware zipfile there are 3 epromfiles and some info :
M500 gcode now doesn’t store Esteps value to EEPROM preventing weird behaviour when upgrading MK2 to MK2 MM
Would make sense if the change only the affects the multimaterial firmware ?!?

Posted : 22/08/2017 4:41 pm
JeffJordan
(@jeffjordan)
Member Moderator
Re: setting esteps for extruder calibration


Also regarding the m500 command not storing steps , isn't that only for the MM firmware ?

In the firmware zipfile there are 3 epromfiles and some info :
M500 gcode now doesn’t store Esteps value to EEPROM preventing weird behaviour when upgrading MK2 to MK2 MM
Would make sense if the change only the affects the multimaterial firmware ?!?

I think it has been disabled accidentially for all versions. either wait for the next release or compile the firmware yourself and use the ConfigurationStore.cpp from the previous version (where it has still been enabled).

dem inscheniör is' nix zu schwör...

Posted : 22/08/2017 10:47 pm
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