Blobs and under extrusion with S3D

[pogo1213]

Hardware
Titan and v6 direct

Adjusted retraction distance and speed and with each retraction on the outside shows a blob and under extrusion after the blob. Any ideas?

[Phaedrux]

If you have firmware retraction setup for S3D you could try this to help make it easier to tune:

https://forum.duet3d.com/topic/5993/firmware-retraction-tuning-with-macros/9

What are you currently using for retraction and extruder speed settings?

[pogo1213]

Started with .8mm retraction at 1200mm/min now up to 1.8 at 3600mm/min with no fix

[Phaedrux]

@pogo1213 What's your extruder max speed, accel, and jerk set to?
What material and temp? What is your unretract speed? Pressure advance? Travel speed and acceleration? Are you using S3D coasting? Have you run a PID tune on your hot end heater? Have you measured your filament diameter and calibrated e steps? How fast are you trying to print?

I can give you my settings I use for my Titan Aero, and while similar to the V6, there's no guarantee they will fix your issue. There's a lot of variables at play.

M201 E8000                         	; Set maximum accelerations (mm/s^2)
M203 E15000                        	; Set maximum speeds (mm/min)
M204 P3000 T4500					; Set printing and travel accelerations
M566 E3000                            	; Set maximum instantaneous speed changes (mm/min) (Jerk)
M207 S0.8 R0 F7200 T1200 Z0.0  ; retraction settings
M572 D0 S0.05 ; pressure advance for PLA direct drive

[pogo1213]

I am currently testing this
M566 X900 Y900 Z12 E3000 ; Set maximum instantaneous speed changes (mm/min) start 900
M203 X6000 Y6000 Z180 E15000 ; Set maximum speeds (mm/min)
M201 X500 Y500 Z250 E8000 ; Set accelerations (mm/s^2)
M906 X800 Y800 Z1200 E1200 I30 ; Set motor currents (mA) and motor idle factor in per cent
M572 D0 S0.05

but so far still having blobs

[dc42]

Your extruder speed and acceleration are set very high. Are you sure you are not getting missed steps during retraction?

[pogo1213]

@dc42 I started far below as noted below:
M566 X900 Y900 Z12 E120 ; Set maximum instantaneous speed changes (mm/min)
M203 X6000 Y6000 Z180 E1200 ; Set maximum speeds (mm/min)
M201 X500 Y500 Z250 E250 ; Set accelerations (mm/s^2)
M906 X800 Y800 Z800 E1200 I30 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

and I was getting similar results that was discussed here:
https://forum.duet3d.com/topic/849/tweaking-for-perfect-jerk-accel-pressure-advance-blob-removal/28

I have dropped my retraction all the way down to 0.2mm but after the retraction it under extrudes for ~15mm. I have a print running with a higher pressure advance to see if that makes a difference

[Phaedrux]

@dc42 I only got hiccups when testing 256 microstepping. With 16 Ive never noticed any.

[pogo1213]

i attempted 0.2 pressure advance and it looked better so Im attempting 0.5

[Phaedrux]

@pogo1213 are you using a Bowden setup or direct drive? 0.5 is quite high for a direct drive.

[pogo1213]

direct but Im running out of possible solutions

[pogo1213]

0.5 was to much but 0.2 has worked pretty well but it hasn't solved it just made it look slightly better

[pogo1213]

I have retraction down to 0.2mm without stringing and no longer leaving blobs just leaving a void immediately after the retraction

[dc42]

@pogo1213 said in Blobs and under extrusion with S3D:

I have retraction down to 0.2mm without stringing and no longer leaving blobs just leaving a void immediately after the retraction

You can use "Extra restart distance" to avoid that.

[zerspaner_gerd]

I also have a larger Z-seam with S3D.
With Cura I have much smaller nicer ones.

I could not find any differences between the two gcode files.

Here are the two gcode files:

1_1532300304525_S3D.gcode
0_1532300304525_Cura.gcode

[pogo1213]

@zerspaner_gerd what type of extruder?

[pogo1213]

This post is deleted!

[pogo1213]

After a large amount of tweaking Retraction speed and distance (ending with 0.2mm distance and 5000mm/min speed), Pressure advance (0.05) and extra restart distance (ranging from 0 to 0.2, settling on 0) I still have a small seam. Any other suggestions?

https://drive.google.com/file/d/176qYIU3DtLloxzfob3uDFD5SV3tU5ere/view?usp=sharing

https://drive.google.com/file/d/1rS7onyxYcRK3mBEMIRk2-sgEGEXSywZ0/view?usp=sharing

https://drive.google.com/file/d/1-vrav9f9cwBVXSd_euZr62YmYs5Tix7e/view?usp=sharing

[Phaedrux]

That's a quite good seam actually. You'll never completely eliminate it. Now the trick will be trying different options to hide it in the model. I'm not very familiar with simplify 3ds options but I assume it's similar to slic3r and Cura and gives you the option to try and hide it on the sharpest inside corner or align it to a specific place. It'll depend on the model on which will work best. On angular shapes I find it easier to align it to the sharpest corners. On more organic shapes I usually just align it to a single side.

Have you also tested for stringing between travel.moves yet? 0.2mm is fairly low. How about an actual print?

[pogo1213]

I ran a retraction test (4 spikes in a 20x20mm square) with great results at 0.2. I also printed a few parts in pla with no issue, PETG Im bumping it up to 0.5-0.8 to get great results.