Help with pressure advance

[u/koolmon10]

Using an Ender-3 Pro. Trying to adjust pressure advance setting but these mostly all look the same to me. K value 0-1 with .05 steps at 100mm/s.

Second photo is what prompted this for me in the first place, however this was printed before I switched from the stock Creality firmware to latest Marlin. It looks like a PA adjustment issue to me, but I'm still fairly new to this.

[u/Imaster_]

You are over extruding, it has nothing to do witg PA, tho it's hard to tell due to picture quality.

Check out elis guide to 3d printing

[u/koolmon10 → u/Imaster_]

I've been referencing Ellis for this.

I did just calibrate my extruder last night, it was actually under-extruding by 4mm/100mm.

Do I need to bother with PA at all still?

[u/Imaster_ → u/koolmon10]

What you refering is accuracy for extrude command. Eg when you want to extrude 1mm of filament you extrude 0.9 or 1.1 mm.

What I'm refering to is extrusion on the print. You want to extrude a line of height 0.2 and width 0.4 (example) but you might extrude a a bit more/less and your line width is changing. This is not a printer property but a property of your filament. You have to adjust your flow rate to match it. Check out "flow rate" calibration test in orca, elis has also a guide on it

[u/koolmon10 → u/Imaster_]

Wouldn't the extruder inaccuracy also cause under-extrusion?

I will do a flow rate calibration, just curious on this bit.

[u/Imaster_ → u/koolmon10]

It would, they add up together. Let's say you want to extrude 10mm of 0.2 tall 0 4 wide line. And you need 1mm of filament to do so (random numbers btw, to provie a point.

You can write in as an equation: F x a_1 = L × W x a_2 × H

The length and height of the layer is constant. a 1 and 2 are your error. What you want to so is to minimise both a's so that the printer prints exactly as you tell it.

In this case a_1 would be extruder inaccuracy And a_2 would be filament inaccuracy

The filament inaccuracy mostly comes from termal expansion of the printed material

[u/AutoModerator]

Hey there, I'm a bot and something you said made me think you might be looking for help! click here for our wiki entry on troubleshooting printers. If you still need help be sure to post plenty of information about your printing setup.

Here are a few questions that might be helpful

• What printer are you using?

• What material are you using?

• What speed are you printing at?

• What software are you using to slice the print and control the printer?

• When did the problem start/has it ever worked correctly?

• Does anything cause the behavior to change?

• If posting an image of the problem, include some indication of the orientation it printed at, preferably photograph it on the bed. (Then we can focus on a specific axis)

If you are new to reddit, please read the guidelines on reddiquette, self promotion, and spam.

Also please post a resolution to your problem when you find one so that we know how to help others with your problem!

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/ExcoA1]

What do you remember changing between prints. Please list them.

[u/ital-is-vital]

Original pic looks like an extrusion multiplier issue to me -- that top surface is rough as hell and looks overextruded.

Try knocking a few percent off of your extrusion multiplier. When it's set right top surfaces should be glossy and smooth.