Pressure Advance seems to not be working.

[burtoogle]

That crap in the last image is most likely to be caused by un-retracted travel. If you are using combing, you really need to set the max comb distance with no retract setting to something like 10, 20, etc.

[Phaedrux]

If you correct for the coasting issue mentioned you may get some better results on the seam from higher PA values than 0.7. I'd also try upping the extruder acceleration a bit. Say 3000ish.

[Phaedrux]

Also, as pressure advance increases the amount of retraction needed decreases, so even though it's noisy, some of that noise can be reduced after you find the PA value by retuning your retraction amount. You can also probably reduce the retraction speed a bit.

[Samuel235]

@burtoogle - I do have combing enabled, but its set to 10. Your branch of Cura freezes up when its idle for about an hour or so, I have to keep reopening it up when I get back to testing a new set of slicer dependant settings. Not a problem, just thought I would let you know

@Phaedrux - I have changed my retraction to 3mm at 40mm/s. I will increase the extruder acceleration now as you suggest. Would you go lower than 3mm, I can test this out myself but while I print a test with these new settings just thought I would ask.

[burtoogle]

@Samuel235 said in Pressure Advance seems to not be working.:

@burtoogle - I do have combing enabled, but its set to 10. Your branch of Cura freezes up when its idle for about an hour or so, I have to keep reopening it up when I get back to testing a new set of slicer dependant settings. Not a problem, just thought I would let you know

What OS and HW are you running Cura on? I haven't had any other reports of my builds freezing.

[Samuel235]

@burtoogle - Windows 10 on 8GB RAM, i5-3570K @3.4GHz (stock, not OC'ed) with a AMD Vega 56. If you need any specific information, please feel free to contact me privately to avoid clogging this thread up, more than willing to chat.

[Phaedrux]

@Samuel235 said in Pressure Advance seems to not be working.:

I do have combing enabled, but its set to 10.

I dislike combing, I'd much rather retract at all times.

[Samuel235]

@Phaedrux - Combing has now been disabled, i'm joining the dark side!

[Samuel235]

I'm getting a little confused between M201 and M204, the duet gcode page is saying that M201 is per axis acceleration and M204 is for printing overall, will only the lowest value get used when it comes to printing?

[Phaedrux]

M201 sets the maximum value for all cases. M204 is optional and gives a bit finer control by separating print and travel moves and lets you use higher acceleration on travel moves. This can be controlled in the slicer now as well with much finer grained control still.

It comes down to preference where and how you set those values. And as long as you're aware it doesn't really matter. Some people like to use M201 in config.g and leave it at that with acceleration set the same for all moves. Or maybe use M204 and split print and travel. And others like me use the slicer to have fine grained control over each move type. I use faster for travels, medium for internal areas, and lower for external surfaces. Cura is best for this. PrusaSlicer has more limited control over acceleration and no control of jerk.

[Phaedrux]

More to the point maybe. I'm not sure which will take precedence. If M201 sets a limit at 1000, and M204 sets print moves at 500 and travel at 5000, I'm not sure if M201 will override the M204 or if M204 just sets the new limit.

Even if using M204 you'd still need to use M201 to set the values for all axis since M204 only applies to XY movement I believe.

[Samuel235]

Thanks for that, much appreciated, makes a little more sense now.

I have now kicked off a print with no coasting and 3mm retraction at 50mm/s and the following acceleration/jerk settings:

M566 X700 Y700 Z60 E3000        ; Set maximum instantaneous speed changes (mm/min)
M203 X18000 Y18000 Z3000 E15000 ; Set maximum speeds (mm/min)
M201 X2000 Y2000 Z250 E3000     ; Set maximum accelerations (mm/s^2) 
M204 P1500 T2000                ; Set printing acceleration and travel accelerations

This print is testing the following PA values:

Layers    | PA Value
0 - 25    | 0.5
25 - 50   | 0.0
50 - 75   | 0.6
75 - 100  | 0.0
100 - 125 | 0.7
125 - 150 | 0.0
150 - 175 | 0.8
175 - 200 | 0.0
200 - 225 | 0.9

[Samuel235]

A PA value of 0.7 is still giving me issues. How low should I realistically be looking to take the retraction down to when PA on? This was down to 3mm retraction at 50mm/s...

The interesting thing is that the one line in the infil actually printed with the PA set to 0.9 but nothing else on those layers did...

[Phaedrux]

You could do a reverse test for finding the retraction value. Leave PA set at 0.7 and vary the retraction from 0 to 3mm.

[Samuel235]

This was with 1mm retraction, will be dropping it lower tomorrow:

[zapta]

I spent months struggling to get a decent print quality from my 600mm bowden setup and the problems went way once I switch to a direct extruder.

Just saying

[Samuel235]

I'm waiting for Voron Afterburner to get released out of Beta before switching back to direct drive (have two Wilson 2 printers with Direct Drive). This is simply to get me through to the point where I can print very nice prints until that point. But to be honest with you, I'm burning through filament and time at a crazy speed to get this single issue ironed out, I might just jump onto Voron's direct drive while its in BETA version.

[Phaedrux]

Have you printed much other than test cubes for pressure advance? You can still learn a lot by just adjusting it while printing an actual object. Some pressure advance is better than no pressure advance even if it's not the perfect amount.

The Wilson was my first printer by the way. Good little machine for the time.

[Samuel235]

I haven't, no. I'm about to start printing things with PA of 0.5 to see how it is, ill bring my retraction back up a little bit to 3mm and see how I go from there. I will pick PA testing back up when I convert over to Direct Drive I think, I hate having bowden in the setup, I would much rather sacrifice some speed for quality.

Its still bugging me seeing the extrusion just straight up fail with those PA values I were testing with, I feel like its just a single setting that is hurting my experiments but i'm unsure what it is.

I really enjoyed my time using the Wilson 2's, but I'm so over the sketchup design and the way it performs its probing. I'm all for CoreXY now since joining in with Voron 2.

[oliof]

I have completely disabled PA after switching to KISS with it's looping seam hiding. When going to Hemera, I also disabled KISS' PreloadVE settings which is like slicer based PA to my understanding (but working of an experimentally deduced viscosity model of the material used).

Supermerill's Slic3r++ fork includes looping seam hiding as well, but I haven't tried it yet (the latest build crashes at launch and I haven't tried to figure out why).