CAlibrate Extruder E-Steps?  

Re: CAlibrate Extruder E-Steps?

I am trying to get an answer on this. Do we need to calibrate the extruder e-steps on the MK2? Is this not a known quantity if the setup is stock? Wouldn't we just adjust the extrusion multiplier to fine tune the extrusion?
yes.
just explained it here.

💡 inside the firmware (Configuration_prusa.h) the number of micro-steps required to move the filament 1mm is predefined with 161.3.
http://shop.prusa3d.com/forum/original-prusa-i3-mk2-f23/kit-printed-beautifully-now-under-extruding-t4060.html#p30210

➡ this value is determined from the design parameters of the hobbed pulleye.
but because the pulleye is a real made piece of hardware, you'll always get tolerances of a few microns... which will lead to a notable deviation to the required value (especially because the part is very small).

🙄 to do a proper e-steps alignment, you can test the actual extrusion with this method. and apply the new values with the required commands thru pronterface or octoprint.
M92 Exxx.xx
M500
M501
M503
while xxx.xx represents the new (calcualted) value for the amount of microsteps that you need to push the filament 1mm ( = 1000 µm).
in fact the M503 command is obsolet, just to check if the printer digested the new value properly.

Re: CAlibrate Extruder E-Steps?

Thank you very much for the explanation. Doing this through Pronterface writes back to the printer so I don't have to add it to a start script?

Re: CAlibrate Extruder E-Steps?

So once I determine the new value I can just send the commands -

E92 Exxx.xx
M500
M501
M503

To set the new value in the EEPROM?

Re: CAlibrate Extruder E-Steps?

damned... had a typo: must be:
M92 Exxx.xx
M500
M501
M503
not: E92....
with this sequence the new e-steps value should be stored inside the eeprom and you don't have to tweak this inside your scripts...
but beware that you need to have firmware 3.0.10 installed.
in previous firmware releases of the prusa branch the M500 command (the one that stores the values inside the eeprom) was disabled.

Re: CAlibrate Extruder E-Steps?

Thanks, I am on the latest publish which I believe is the one you mention. Can these commands be sent via S3D? I have never used Proterface!

Re: CAlibrate Extruder E-Steps?

I am trying this but it is nor storing the new values.

Re: CAlibrate Extruder E-Steps?

Thanks, I am on the latest publish which I believe is the one you mention. Can these commands be sent via S3D? I have never used Proterface!
damned, it happens always to me that i mix up the G and the M commands.

the command to set the steps per unit is the M92 command !

just checked it with the machine control inside s3d, and it works.
but i unchecked the nasty temperature monitoring, which was annnoying for me.

try to send the M503 command first.
you should get back a lot of information. at the first lines you should get something like:
SENT: M503
READ: echo:Steps per unit:
Steps per unit:
READ: echo: M92 X100.00 Y100.00 Z400.00 E171.78

then send something like:
M92 E171.79
which should be confirmed with "READ: ok"

then sending the M500 command to store the value inside the eeprom, you should get the following:SENT: M500
READ: echo:Settings Stored
Settings Stored
READ: ok

retrieving the settings from the eeprom into the actual configuration should be acknowledged as well with a READ:ok:SENT: M501
READ: echo:Stored settings retrieved
Stored settings retrieved
READ: ok

when you then sent the M503 command (to display the printer settings), you should read the new value at the 4th line, like:SENT: M503
READ: echo:Steps per unit:
Steps per unit:
READ: echo: M92 X100.00 Y100.00 Z400.00 E171.79

sorry for the mess with the M and G ....

Re: CAlibrate Extruder E-Steps?

No problem and thanks! I got it with the M command from another post!! I think I got it done. Thanks for all the help.

Re: CAlibrate Extruder E-Steps?

This process is need to be done every time I change filament?

Re: CAlibrate Extruder E-Steps?

This process is need to be done every time I change filament?

normally the values shouldn't change when you change filament, because they are mainly determined by the physical dimensions of the extruder pulleye .... as long as the filament doesn't start to slip at the hobbed pulleye.

but it might be that you wear down the little brass pulleye when you often use abrasive materials and that you need to recalibrate the parameter before replacing the pulleye with a new one.
it's a little bit like the clutch between you car's motor and its gear box.

Re: CAlibrate Extruder E-Steps?

Ok thank you very much.

Re: CAlibrate Extruder E-Steps?

On a follow up question. Now that I have calibrated the extruder would I drop the extrusion multiplier to .9 instead of the 1 that it is set at for PLA as is the norm?

Re: CAlibrate Extruder E-Steps?

On a follow up question. Now that I have calibrated the extruder would I drop the extrusion multiplier to .9 instead of the 1 that it is set at for PLA as is the norm?
no.
your printer should now print the objects with extrusion multiplier 1.00 as they were sliced and intended to appear.
and they should have the calculated weight as well.

normally you'll only have to mess around with the extrusion multiplier when you've got filament with a diameter out of specification (for example 1.8mm instead of 1.75)

if you got "over-extrusion-effects" with a certain .gcode that you print, then it's most likely that somebody has pre-compensated expected under-extrusion.

Re: CAlibrate Extruder E-Steps?

Ok, was just wondering since in S3D for example on my other printers we normally set PLA to .9 and ABS to 1 for the extrusion multiplier as a starting point.

Re: CAlibrate Extruder E-Steps?

no.
your printer should now print the objects with extrusion multiplier 1.00 as they were sliced and intended to appear.

This doesn't work on every PLA. White PLA being the most serious offender.

I've calibrated my E-Steps on the stock Prusa MK2 Extruder, and now on the upgraded Titan Extruder again and again, also did the 2 Shell wall thickness correction. (which is about 0.98 EM)

While black PLA prints beautifully with absolutely no flaws, it's impossible for me to get a smooth wall with white PLA.

See here: http://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/help-getting-rid-of-z-banding-visible-horizontal-l-t4069.html

The only thing that i can do is drop the Extrusion multiplier way down to 0.8 or 0.85 (20% less material) go get smooth and shiny wall. At the cost of gaps in the top layer.
Over the weekend i've printed about 20 white Benchys with various settings in the Advanced Tab and the Filament Tab in Slic3r, only a combination of 0.8x with 0.6x top infill works.

I've tried various white PLAs, from brand manufacturers like Hatchbox, Das Filament or Verbatim. Current Filament thickness is on average 1.76mm

I don't get whats causing this whit white filament

Re: CAlibrate Extruder E-Steps?

One reason I was asking is I did a Benchy in silver after calibrating and it came out good but the letters on the stern were not clear. Dropping to .95 was a little better and have not tried at .9.
I know there are a lot of factors so just interested in opinions and thoughts.

Re: CAlibrate Extruder E-Steps?

@devilhunter & wirlybird:
at which resolution (with which perimeter & infill settings) did you both tried the benchy ?

Re: CAlibrate Extruder E-Steps?

@devilhunter & wirlybird:
at which resolution (with which perimeter & infill settings) did you both tried the benchy ?

0.10mm
0.15mm

with 10% infill, 2 shells and 0.45 perimeters in advanced (stock prusa settings)

black Benchys come out splendidly, white Benchys look like it randomly overextruded

Re: CAlibrate Extruder E-Steps?

This is interesting:

http://makerstoolworks.com/all-filament-is-not-created-equal/

All Filament Is Not Created Equal

In this month’s tech note I wanted to discuss a question that has came up several times in our chat channel concerning choice of filament color. We recommend that you do not choose white or black as the filament color if you are new to 3D printing. There are a couple of reasons for this that I will try to explain.
The first would be regarding black filament. When first learning to use your printer getting your hotend temperature set properly can be a bit tricky. To get the best setting requires looking at your test prints and determining if you need to increase or decrease your temperature. The black color can make it difficult to see the subtle difference.

With white filament its even a bit more tricky. The pigments used in almost all white filament change the flow characteristics as well as being difficult of seeing the subtle differences that temperature can make. Concerning the flow issues it has to do with back-pressure, the white filament has more viscosity and can drive you nuts trying to fine tune. This issue can be seen on the image in this article.

For users new to printing, the artifact can be difficult to minimize. Bowdens style extruders amplify this issue.

For people new to 3D printing choosing a color such as blue, red, green, yellow will make it much easier to learn to print instead of fighting issues related to color specific problems.

No wonder i have such problems with white filament.