M572 settings

weput

Hello forum…

I'm just writing as im kind of pissed/desperate...

Happens that i enabled pressure advance with M572 D0 S0.15 and produced about perfect prints on my custom build i3... but honestly, never did a high retraction demand print...

now, i got this 3dhubs job and my e3dv6 jams and jams every time up to the point that my titan goblin is grinding the filament...

anyways, to stop wining, what retraction setting are you guys using/recommend?
shall i enable coasting on s3d for example?

my bowden tube is about 540 mm long...

deckingman

TBH if your nozzle jams and the extruder is grinding the filament, playing around with retraction is unlikely to help. It's more likely to be that you are trying to print too fast, or maybe the temperature isn't high enough for the filament you are using? I'd go back to basics. That is to say disable pressure advance then set to a lowish print speed and print tower, say 20mm x 20mm x 100mm high. Alter the temperature by 5 deg C every 10mm and observe the print finish and look out for any signs of under extrusion. Once you've found the best temperature for your filament/machine combination, print two towers spaced say 100mm apart and vary the retraction until you just lose any stringing. Once you done all that, then you can experiment with pressure advance and maybe revisit the retraction setting. That's what I'd do anyway…....

dc42

I've only used Bowden extruders, and I reckon on using retraction length around 0.9% of the Bowden tube length plus around 1mm. Use the minimum retraction that avoids getting tiny blobs on the print at the start of travels moves. Bear in mind that as you increase pressure advance, you need to decrease retraction distance.

If you only print PLA then the E3D Lite 6 may be a better option because it it much more tolerant of over-retraction without jamming.

weput

well.
i removed the M572 command and it didnt jammed.. so yeah…

thank you dc for your formula.. I'm 100% convinced that bowden IS THE WAY TO GO.
retraction was at 3.5mm @60mm/sec... went down to 3@40... no luck.

i made a print with no pressure advance and it did ok (it ozzed... but ok)
I'm testing now with 2.5mm and S0.1 to see what happens...