Thanks to you both ! It is awesome to find such great support in this forum ! I cant tell you how happy it makes me to see a new drawing-bot will do its first correct moves soon

Hello All.

as the official release, at least the RC-Versions of the firmware now seems to support Dual-Scara.... yeehaa.
thx to Jörg, Bondus, DC42 and all the other people made this possible !!!

Before running in a completely wrong direction i wanted to ask you if there is in your opinion a disadvantage of placing
the steppers like in the Photo. This ways both arms have the same "pivot-point". I am not sure If it is a bad idea because of leverage etc. or the firmware runs into some 0-degree problems....

photo_2020-03-03_17-03-22.jpg

Hopefully i can do my first tries the next days with a new config on the Duet2Wifi.

Best, Johannes

@deckingman said in massive overextrusion, E-Steps are calibrated:

@Enpixa You need to adjust that first layer. The nozzle is too near the build platform. You can see it in the fact that it's leaving a line in the non-print moves between those circular features are the rest is just too squashed. So it looks like over extrusion because it's being forced out sideways due to the proximity of the nozzle to the build plate. Use baby stepping if necessary but whatever means you use, the nozzle needs to be 0.2mm or so higher on that first layer.

Deckingman, you are right, that was due the testing-phase, will increase the distance and show you updates soon. Had tested everything from very close (now) to very far ) Didnt help with the overextrusion.

I wanted to thank you all for your input.

Atm the main-problem is still not solved but before further hunting for the overextrusion-issue and all the suffering :), i thought it is a good time to replace the old part-cooling-system which i got from Grabcad and never convinced me because the ducts were oriented 90° directly to bottom (but it looked awsome )

So i opened my old loved Rhino3D an started to model a new cooling-system from scratch, simple, but hopefully well performing:

I keep you updated ! When i approved that the new cooling fans are doing well, i will provide the model on grabcad.

Hunting over-extrusion will start soon again.

@Veti said in massive overextrusion, E-Steps are calibrated:

what temperature are you printing at?

also make sure your retraction settings are working
print this
https://www.thingiverse.com/thing:2766430
and check with differernt retraction distances

Veti, at the moment at 205°, but had pretty the same results with 190°

@Phaedrux said in massive overextrusion, E-Steps are calibrated:

It's not uncommon to set the extrusion factor in the slicer to 90-95% to get clean prints. I'd say your first layer just needed to be a bit higher. The layers afterwards look ok.

there is one example with offset 0.25 and 100%, for me it already looks like too far away. Lines on first layer diesnt stick together anymore. Thats why i went for the 0.2 & 100%

Next Update:

measured the Filament, it is ~1.75

Checked Z-Movement: G92 Z0 & G1 Z150 :
Started at 25cm on ruler and it ended at exactly 10cm.

Starting-Point:

End-Point of G1 Z150:

Next printed the Calibration Cube several times. Layer Height 0.16.
1st layer completely, 2nd Layer to the half to show nicely :

Offset 0.15 ( Babysteps ), Extrusion Factor in DWC 70%

Offset 0.20 ( Babysteps ), Extrusion Factor in DWC 85%

Offset 0.20 ( Babysteps ), Extrusion Factor in DWC 90%

Offset 0.2 ( Babysteps ), Extrusion Factor in DWC 95%

Offset 0.2 ( Babysteps ), Extrusion Factor in DWC 100%

Offset 0.25 ( Babysteps ), Extrusion Factor in DWC 100%

Thought, Offset 0.2 and EF 100% didnt look too bad. so went for it
to print it:

View to Infill at about 50% Printtime

Photos of Calibration Cube. It is the same cube, just rotated it for the Photos, Printed with 0.16 Layer-Height:

Any ideas, how i could proceed to get a good print result ?

In Germany we have a saying: "It is the same in green"..... fits perfect to my print result Meanwhile tried it with 4 different filaments. ( All from "high quality" filament companies.

Will measure tomorrow, have my calipers in office. But the filaments work on my other printers fine.

@Veti said in massive overextrusion, E-Steps are calibrated:

1611847978080-iphone_halterung_v26.txt

rename to zip and extract.

Veti, thx alot. Here comes the result of your gcode printed:

@Veti said in massive overextrusion, E-Steps are calibrated:

maybe we could send you a known good sliced g code and you can print that to rule out any misconfiguration in the slicer

Hello Veti, that would be very nice !

Here is a link to the file i am doing all my tests with atm:
iphone_halterung_V26.stl

If someone could slice that proper for further testing. Would be great ! thx alot.

Some more checking:

Now disconnected the stepper from the printers daughter-board on top of the extruder Carriage and connected the stepper directly to the Duet Wifi to double check that there is no issue with the connections or daughtboard. Checked. Seems to perform the same. So connected back to daughterboard again.

Also send some "G1 E7.7" ( trial and error for a full 360° revolution value) which gives a full revolution at the bare stepper. Sent via console, working. fine.

Then wrote a little gcode file for execution:

M83; relative extrusion
M302 P1 ;allow cold extrusion

G92 E0 ;extruder 0

G1 E7.7 F200
M118 S"Round 1"
G4 P4000

G1 E7.7 F200
M118 S"Round 2"
G4 P4000

G1 E7.7 F200
M118 S"Round 3"
G4 P4000

printed via DWC:

Works fine:
Video of executing that file: video_2021-01-28_15-52-49.mp4

Performs like it should. No "over-extrusion" or double revolution seen here. Maybe this helps to get a step closer to the origin of the
over-extrusion problem.

Little Update: Meanwhile i replaced the Duet Wifi mainboard with another one i had here in my shelf. Rewired everything.

The whole story again. Reinstalled Firmware 3.2 completely new. ( Also DWC 3.2 etc. ) Also used another SD-Card. deleted all folders before. The only thing i copied was the config-files to sys folder from the "old" board.

Did new PID for heater.

Checked again, 100mm is moved when doing the G1 E100.

Heightmap doesnt look too bad:

Checked nozzle distance to bed again with the good old "paper-method" using standard 80g paper. Nozzle is barely touching the paper. Really only slightly, it doesnt bend nor really scratches it. just a little feel of.. there could be paper

Print result at 100% Flow: same old story.

i am going crazy !

@droftarts said in massive overextrusion, E-Steps are calibrated:

M92 M350 M221

Hello Droftarts, thx alot. Always the same result.directly after starting, after homing, while printing, after printing/aborting:

27.1.2021, 19:23:00	M92 M350 M221
Steps/mm: X: 80.040, Y: 80.040, Z: 800.960, E: 415.800
Microstepping - X:16(on), Y:16(on), Z:16(on), E:16(on)
Extrusion factor(s) for current tool: 100.0%