Firmware 3.4b7 - firmware retraction bug

natthapol.v

@dc42 Hi, I haven't enable Pressure Advance on this firmware as seen in the attached filament config file.
I've had issue with pressure advance grinding the filament in the extruder on long bowden setup. Probably due to my pressure advance, extruder jerk/acceleration settings so it has been disabled on this machine.

system config.g
filament config.g

danzaywer

@dc42
I can confirm this strange behavior. I have an afterburner direct and from 3.4b6 I started to have problems with clogging in the parts where there were many retraction commands during the prints and the sound of the retraction was accentuated compared to 3.3. Same with 3.4b7. The parameters were M207 S0.5 F2100 Z0.0, I changed to M207 S0.2 F500 and for now it seems that the clogging is gone.
No pressure advance.

bberger

I can also confirm that something is off with PA in the 3.4 beta release(s?). I just upgraded from 3.3 to the 3.4b7 and with PA on the printer doesn't feed enough filament anymore.

Basically similar behaviour you'd get when either turning up PA too much (I use 0.15 on a very short bowden tube on a flying extrude) or use too low retraction speeds.

When I turn off PA the issue is gone.

Argo

@bberger

I had similar issues with input shaping + pressure advance in 3.4b6:
https://forum.duet3d.com/topic/26062/3-4-0beta6-new-input-shaper-disturb-pressure-advance/8?_=1641083316188

Maybe there are issues with higher PA values in general.

natthapol.v

@argo I have not had my PA activated for this issue to happen. I believe this issue neither related to Pressure Advance nor Input Shaping.

dc42

Can any of you provide a short print (preferably only one layer) and associated config.g file that reliably demonstrates this issue? Preferably in the form of the sound being different between RRF 3.3 and 3.4beta7 when the printer settings are identical. I don't mind whether PA is needed or not.

natthapol.v

@dc42 Hi, I will setup some print files and all the associated settings and send it to you in couple of hours.

dc42

@natthapol-vanasrivilai @danzaywer has either of you been able to produce a GCode file and associated config.g file that reliably demonstrate this problem?

@Argo if your issue only occurs when high PA and IS are together then I think it is a different issue. We already know that when input shaping is enabled, PA is affected and may need to be tuned again.

danzaywer

@dc42 My current configuration would not work on 3.3, I have to bypass the toolchange macros. Anyway, can I downgrade from 3.4b7 to 3.3 simply by uploading the 3.3 files?

dc42

@danzaywer said in Firmware 3.4b7 - firmware retraction bug:

@dc42 Anyway, can I downgrade from 3.4b7 to 3.3 simply by uploading the 3.3 files?

If you are running the Duet in standalone mode, then yes.

natthapol.v

@dc42 Hi sorry that it took too long on my part.
I've attached the zip containing the files from SD card.

config, gcode, filament and macros that are used in startup/ending sequences.

The forum doesn't allow me to upload zip file, so please rename the file extension to ".zip" afterwards
repo.txt

The attached gcode file is just a bunch of 5x0.2mm hollowed cylinders. The machine and gcode is setup to do firmware retraction.

Argo

@dc42

Coming from 3.3 the same PA values (with input shaper enabled) result in more or less bulging corners with 3.4b7. Increasing PA (from 0.065 to almost 0.1) then to get almost as sharp corners as with 3.3 results in starving infill lines which do not connect properly to the perimeter.
I‘ve added pics in my other thread.

danzaywer

@dc42 I still can't downgrade but I found out what could have caused the problem: the M563 command in config.g (but also from the console) resets the retraction of the tool, so M207 must follow M563.

natthapol.v

@dc42 I have found something interesting. Since the firmware retraction behave unexpectedly, I've switch to slicer retraction and ran some test prints. The retract/unretract or let say any commands that involve extruder movement. Sometime the extruder move at a very high speed as well (Command that involve pure extruder move e.g. G1 E5).

This show that the issue is not purely related to retractions.

I think it will be easier to debug the issue by simply setup a gcode with a bunch of G1 E** commands and observe the extruder speed.

Hope it help for further investigation.

dc42

@natthapol-vanasrivilai I've run your test file several times using both RRF 3.3 and 3.4b7, but I was unable to detect any differences in the sound. I disconnected the X and Y motors so that I could hear only the extruder motor.

However, when I enabled debug output I did see a different between RRF versions. This difference might occasionally cause the first 2, 4 or 8 microsteps of an extruder movement to be performed rapidly instead of at the correct speed. It is possible that this might explain the difference in sound you heard.

I have corrected this and put a new RRF firmware build at https://www.dropbox.com/sh/up0gytwkxcn4if2/AACO6rIrTu5kPSgMxOmjmxdZa?dl=0. Please try it.

Diamondback

@dc42 When this behavior happens to me, it lasts for the entire commanded movement of the extruder, so I don't think that anything about a few microsteps would create that sound. I'm confused why it only happens to rarely, just yesterday night it happened again during my normal filament unload macro.

dc42

@diamondback can you provide a test file that reproduces this behaviour?

Diamondback

@dc42 I'm afraid I can't, it happens seemingly randomly when unloading filaments via the DWC feature. The gcode that is running when it happens is posted in my first post in this thread.
For what it's worth, it's a TC design with 4 tools, it seems to happen on all of them from time to time (ie. I've seen it happen on every tool at least once, it's not restricted to a specific tool)

dc42

@diamondback the G91 and G90 commands in that macro will have no effect. You should replace G91 in that macro by M83 and remove the G90 line. That will probably fix the issue for you.

natthapol.v

@dc42 I'll test with the attached firmware and let you know how it is