MK4S Incorrect Pressure Advance
Hello,
I realized that on the new Firmware PRUSA has changed the old Linear Advance technique with a new Pressure Advance (like Klipper calls it)
So the old M900 command has been deprecated, and on the new GCODE there are only M572 (Pressure Advance).
However, I noticed that I did not get good print after the MK4S HF upgrade, and I looked at the Pressure advance values on the stock profiles.
As example, for PRUSAMENT PLA @MK4S HF (nozzle 0.4) there is a value of 0.036
This stock value does not seem good for the new HF MK4S nozzle or the new firmware. So, I performed the Pressure Advance test, and the result was that the default value is incorrect as you can see. In the wide test, the 0.036 has still deformation:
It would be better values around 0.050. So I run the test again with fine values of 0.001 steps:
looking at it, 0.054 seems to be the best value. So I changed the Start-gcode settings in Filament Advanced for PRUSAMENT PLA, and now it is:
M572 S{if nozzle_diameter[0]==0.4}0.054{elsif nozzle_diameter[0]==0.5}0.026{elsif nozzle_diameter[0]==0.6}0.02{elsif nozzle_diameter[0]==0.8}0.015{elsif nozzle_diameter[0]==0.25}0.12{elsif nozzle_diameter[0]==0.3}0.08{else}0{endif} ; Filament gcode
M142 S36 ; set heatbreak target temp
I will change to this, on all my PRUSAMENT PLA filament settings. Then I will have to test on other PRUSAMENT filament types and other brands.
- Did someone else tested this ?
I attach the gcode-tests, for people that wants to try on printer.
Regards
RE: MK4S Incorrect Pressure Advance
- Did someone else tested this ?
Hi Antimix
I used your wide file and got similar results on my MK4S upgraded from MK3S using the high flow nozzle.
I was having trouble with a brim on a print looking very "lumpy" which was fine on my MK4S MMU3 with a regular 0.4 Nozzle.
I changed the value from 0.036 to 0.053 and the brim was pretty good. The rest of the print ( a thin flower stalk) was very similar to the print with the default 0.036 setting. It was just the brim which was different.
I tried your 'fine' file and got gradually worse results from the start of 0.044 suggesting that the 0.036 setting was best. I was confused.
wide test
Filament ran out and I changed colour during wide test.
fine test
So I tried the 0.053 setting as a start point based on the wide test and the resultant first photo looks good and replicates your results.
Apologies for the fine test photo, the sun came out!
Please forgive any bad formatting or incorrect posting as this is my first post to the forum and adding pictures was hard: OK when you know how to!
Regards
G7RUH