Posts made by jatmn

@T3P3Tony That is correct a "bulge than gap" and in my tests pressure advance has more effect on the gap and start point and less of an effect on the stop (bulge). Values high enough to affect the bulge result usually in a significant gap (actually a hole all the way thru) and under extruded start point.

@Phaedrux

That was posted above already, but here it is.

Grey was RRF
Red was Prusa Mini

Video with more clear detail of the issue

@Phaedrux said in Bug? In Retraction and Movement Junction:

@bot Well he did try these settings: https://forum.duet3d.com/post/202855

M566 X900 Y900 Z120 E3000               				; set maximum instantaneous speed changes (mm/min)
M566 P1                                            ; Set jerk policy to mimic Marlin and uses jerk between all moves.
M203 X12000 Y12000 Z600 E6000          				; set maximum speeds (mm/min)
M201 X4000 Y4000 Z300 E3000             				; set accelerations (mm/s^2)
M204 P800 T2500								   ; set print and travel accel
M572 D0 S0.035 ; PRESSURE ADVANCE
M207 S1 R0.0 F3000 T1500 Z0.0 ; firmware retraction

I thought the results looked better, but ¯\_(ツ)_/¯

I think that was only with 3.1.1 though, and not 3.2.

these settings were tested again on 3.2 results was basically same as in 3.1.1

@dc42 said in Bug? In Retraction and Movement Junction:

@jatmn, have you tried using jerk policy 1 with RRF 3.2 yet?

yes

Sorry this has been an.. lets go with an emotional day so my testing started late today.

Im still running a number of tests with the new 3.2 firmware as well as attempting to try and tune the motion system better..

As I mentioned in my very first post, slicer does not matter.
I am well aware prusaslicer's default settings do no use retraction usually in this junction.
However to rule out that therefore its not related to the issue is a little short-sighted and rather just raises more concern.
Your analysis as stated would mean that prusa's own machines print with results like this, my A/B prints show a print off my Prusa Mini which was sliced with prusaslicer and does not have this issue as shown. (powered by marlin)

However in saying this. This actually further proves at least to me there is indeed some sort of issue in the junction planning on RRF. You don't see the pause because your not retracting but still see the issue I see. This issue wouldn't matter to me if it was a issue found in marlin, having used marlin for several years prior to RRF I can for sure say this issue does not exist in marlin which is why it sticks out as a issue to me in RRF.

While I am currently still running tests for firmware 3.2 currently I can say the results are.. sorta? better? ish? may just not as predominate for sure still producing more or less same issue. Again with minimal influence by Pressure Advance settings as im currently running PA towers right now to see how it changes. I can say my same settings and gcode as posted before in this thread produces basically the same results.

Using low values encourages more of a bulge on the stop point and when the value is increased enough to resolve that, the start point is under extruded causing the same "step" effect in the surface. Im not referring to a seam, im referring to a miss-matched surface.
(
General like the image above, while this is normal with a PA value that is too high causing under extrusion. My issue is similar except the start point is the correct width but the stop section is larger than the nozzle diameter.

I am not the only person with this issue i know many people with this issue that have shelved their RRF powered machines or just completely pulled the board out and loaded a Marlin powered board in the machine.

As I have mentioned in my first post, every time this issue comes up everyone either writes off the issue as resolved when its not, or just abandons the thread. Usually resulting in the user being frustrated and discarding the duet product for something else.

@dc42 said in Bug? In Retraction and Movement Junction:

@jatmn, thanks for your clear description of the issue.

@jatmn said in Bug? In Retraction and Movement Junction:

please let me know if it was fixed in 3.2.x ...

I fixed a bug that caused pauses between moves during the 3.2 firmware development cycle. I think that this bug was only introduced earlier in the 3.2 cycle, but I am not completely certain. So it's worth trying firmware 3.2 if you haven't already.

I will look in to this in the 3.2 update today. However it has for sure existed in 3.1.x as my machines all run 3.1.1 as well as at least 1-2 versions prior to that and had the stated issues.

@jatmn said in Bug? In Retraction and Movement Junction:

The printhead will dwell for just a moment (sometimes an unmeasurable amount of time but can be seen in the print result) during a retraction before moving to the next position.

The print head is supposed to dwell at the current position during any pure retraction move, until the retraction is complete. This is how slicers generate the code, and also how firmware retraction works. But as soon as the extruder motor has completed the retract movement, then of course the next move should start immediately. However, if pressure advance is in use, then depending on the pressure advance setting and deceleration, a retraction may have started even before the retraction command.

I am not a programmer so I don't actually know how this is being done in marlin from a programming standpoint however from a visual standpoint let me describe how this appears. The personality between the two firmware are very much different in this action when you start watching them closely side by side.
Note: This is using slicer retraction not firmware retraction.

RRF

• Move while extruding
• Stop, Dwell
• Retract
• Dwell
• Move to new position
• de-retraction

Marlin

• Move while extruding, Quick junction to retraction
• Dwell if retraction is long (more than about 1.5mm, or has slow retraction speed/jerk)
• Quick junction to new position and de-retraction.

Even while Dwelling Marlin still appears to complete the actions faster, or produce less issues at least.

Anyhow I will give 3.2 a go now as well and report my findings.

@hackinistrator
1, gcode you want is in this thread already
2, don't assume everyone uses S3D just because you do
3, it's 3am here I'm going to bed and not wasting more time on this back and forth with you.

@hackinistrator Uhm please refer to the start of the thread. You appear to not be understanding the root issue or the tests already preformed in this discussion. As your disputing findings unrelated to your assumptions on a test that was already discussed and reviewed with the person that requested it.

@hackinistrator I have posted gcode in this thread of 2 different examples.

And why would you not retract leaving a perimeter? Just because you leave a perimeter it does not mean the layer has completed. Im sorry I don't quite follow your logic on this one.

@hackinistrator it only happens on the stop point. Not the start point or "de-retraction"
Coasting and wiping does not resolve the issue either.

@hackinistrator if you watch the last I think 5 seconds of the video I posted this appears to have the best shot at the very end of the video showing the issue.

In the video if you turn the sound up you can hear my finger nail catch on the red print (prusa mini) this is my nail catching inside the seam which is otherwise even on both sides. The grey print which is the one in question you can clearly see my nail get stuck on the seam but only going over it from one direction. This is the step in the surface between stop and start point, not a gap between the 2 that my nail catches. This is why it's only catching from one direction.

The stop point where retraction is triggered is over extruded. This results in a "bump" in the surface of the shell of the model which generally causes significant issues with parts I print as it causes issues for round objects and thru holes.
It also results in a square having one corner being budged out while the other 3 are clean.

@davekeogh said in Bug? In Retraction and Movement Junction:

@jatmn cheers. I do try. I'll try the same print on my skr running RRF tomorrow.

Do you have shots from prints running Marlin?

my post just before my comment to you has a link to a video showing a print off my prusa mini vs my first print shown in tests here off the RRF test machine.

@deckingman said in Bug? In Retraction and Movement Junction:

@jatmn Just had a quick flick through this thread so I might have missed something. But in a recent post, you mentioned a 1mm nozzle. Is that what you are using? If so, that is the most likely cause of your issues. It most certainly explains why you don't need to use pressure advance because it is highly unlikely that there would be any build up of pressure that needs to be compansated for.
Have you tried a more "normal" size nozzle?
Another thing, have you ruled out all mechanical defects? Are all the gears and hobbed bolts secure on their shafts inside the extruder?

Uhm.. please read just the first post, forget all the rest of the thread it will give a more clear answer of whats going on.. unfortunately non of your comments applied to anything going on at all.

@davekeogh Those are some clean prints, but I do clearly see my issue on them.

@jatmn said in Bug? In Retraction and Movement Junction:

However, it has little to no impact on the stop points.

I'm not sure why you think that. It would have an impact on both. Think about what it's doing. It's shifting the amount of extrusion forward or back in time. It's reducing the amount of extrusion before a stop.

I know this is how it's supposed to work in theory. (or by design)
However literally every one of my tests proves otherwise, or at least the results of the print are proven otherwise.
This is significantly more clearly shown when you run a 1.75mm or 2.85mm Filament on a 1mm nozzle (Which I have noted to have done already)
With an excessively high Pressure Advance value you can cause a significantly delayed start point resulting in a measurable gap between the stop and start points. (on one test I had a 1.5mm gap between the points!)
However, with that, you can still have this over extrusion effect on the stop point even with those settings.
Sorry, I don't have a picture of that, it was a test I had done about 2-3months ago.

As for the result I am looking for, something like this.
Top is Original #1 test from this thread
Bottom is a random print I just did on my Prusa mini

Here is a video that details the 2 prints above
Grey is off mentioned test machine, Red is Prusa mini
Video Link

(also screw Akismet.com spam checker flagging my posts as spam when I edit them)

@Phaedrux said in Bug? In Retraction and Movement Junction:

M566 X900 Y900 Z120 E3000 ; set maximum instantaneous speed changes (mm/min) M566 P1 ; Set jerk policy to mimic Marlin and uses jerk between all moves. M203 X12000 Y12000 Z600 E6000 ; set maximum speeds (mm/min) M201 X4000 Y4000 Z300 E3000 ; set accelerations (mm/s^2) M204 P800 T2500 ; set print and travel accel M572 D0 S0.035 ; PRESSURE ADVANCE M207 S1 R0.0 F3000 T1500 Z0.0 ; firmware retraction

Retuned the motors to 70% of rated max (double-checked the specs first of each motor) which resulted in a slightly higher value on most of them, extruder went down slightly.

Slicing - Ideamaker

• RRF is already set (they have this setting because the Raise3D E2 is RRF)
• Jerk & acceleration control has always been turned off but verified it off
• Coast & wipe has been off for the duration of this testing as requested earlier, confirmed this is still off.
• Retraction on layer change has always been on but verified it on
• Inner perimeter first, outer perimeter second, then infill is default settings in ideamaker but confirmed they were still set
• Set to Firmware retraction in machine settings in Ideamaker
• New Gcode

Image
#1 Original Gcode and firmware/slicer settings as outlined in the initial request of print examples.
#2 Changes as noted above as requested, with the new included gcode.
#3 Same as #2 but changed firmware value of M572 to 0.05 per original gcode to attempt a better start point

Observations
There does not appear to be a real meaningful change in this configuration.
The only real difference has somehow resulted in a now detuned start point that has resulted in it actually under extruded slightly now, which is why I ran an additional test with my old known "good" value for pressure advance which no longer appears to be accurate with these changes. I am guessing this is in relation to your set 1.5mm retraction where I was using 1.25mm or the possible slight speed differences in our retraction settings.

Additional
Im not sure why everyone is still obsessed with Pressure Advanced Tuning.
As I have mentioned, I think a few times now.
In all my tests, yes it can significantly impact start points. However, it has little to no impact on the stop points.
My issue is STOP points not Start points.
In my past tuning, I have tested values from 0.0 to 2.0 in increments of 0.05 and in some ranges when I felt I was close to increments of 0.005
Yes, I have run literally 100's of prints on shapes like this little rod stl trying to tune this issue. It is nothing to do with the STL, I can download any stl from any website or any stl someone generates themselves I can reproduce this issue every single time in any slicer on any of my machines running RRF.
I am not kidding I have literally filled my trashcans many many times with these tiny prints, 25KG+ is a lot of these little buggers.

Did another test because people appear to be fixed on the fact that my z axis speeds are too low.

#1 is the same as the included gcode in the initial request.
#2 is with the following changes as well as pressure advance turned off in the gcode.

M566 P1

M201 X800.00 Y800.00 Z2000.00 E5500.00            ;Z changed from Z200 to Z2000
M203 X12000.00 Y12000.00 Z7500.00 E5000.00        ;Z changed from Z750 to Z7500
M205 X3 Y3 Z3 E50				 ;Z changed from Z2 to Z3 to match XY

This results more or less in the same print I did prior with pressure advance turned off.
It did however make my z axis quite fast and make some really funny winey sounds

You might say that it appears to reduce alot of the banding along the z axis however this appears to mostly be from the rods getting cleaned up and relubricated from the repeated test prints today. This machine has sat mostly abandoned for a few weeks until recently due to the issues.

config-override.g as requested

; config-override.g file generated in response to M500 at 2020-06-08 22:33
; This is a system-generated file - do not edit
; Heater model parameters
M307 H0 A114.3 C401.1 D2.6 S1.00 V23.8 B0
M307 H1 A571.4 C175.6 D5.1 S0.25 V24.1 B0
; Workplace coordinates
G10 L2 P1 X0.00 Y0.00 Z0.00
G10 L2 P2 X0.00 Y0.00 Z0.00
G10 L2 P3 X0.00 Y0.00 Z0.00
G10 L2 P4 X0.00 Y0.00 Z0.00
G10 L2 P5 X0.00 Y0.00 Z0.00
G10 L2 P6 X0.00 Y0.00 Z0.00
G10 L2 P7 X0.00 Y0.00 Z0.00
G10 L2 P8 X0.00 Y0.00 Z0.00
G10 L2 P9 X0.00 Y0.00 Z0.00

Pressure advance turned off as requested
same first 3 as before
#4 Gcode as Provided with firmware changes M566 P1 & M205 ... E50 change as well as setting pressure advance to 0.0
Made the stop point worse, as well as started to cause issues for the start point.

Requested STL model
STL Model
However this request actually makes zero sense, it does not matter what my slicer is generating, I already clearly stated I can 100% reproduce the issue in nearly any slicer.
Also as mentioned, I do not see this issue with Marlin-powered machines with similar configurations or hardware.

Made some tests by feedback noted so far.

Top down
#1 Gcode Provided with no changes
#2 Gcode Provided with firmware change M566 P1
#3 Gcode Provided with firmware changes M566 P1 & I changed M205 ... E50

No notable difference in the issue.

Those values are in mm/sec not mm/min im not using the default M566 version your referring to.
https://duet3d.dozuki.com/Wiki/Gcode?revisionid=HEAD#Section_M205_Set_max_instantaneous_speed_change_in_mm_sec