Pressure Advance

Pressure Advance is a firmware feature that compensates for filament elasticity and flow dynamics within the hotend. Properly tuning Pressure Advance improves print quality, particularly regarding sharp corners and the appearance of the print seam.

This guide explains how to understand, adjust, and calibrate the Pressure Advance setting for your Vision Miner 22IDEX V4 using PrusaSlicer. The goal is to fine-tune extrusion behavior to achieve sharper corners and minimize seam artifacts (bulging or gaps). While we provide well-tested default values in our PrusaSlicer profiles (optimized for a 0.4 mm nozzle), factors like nozzle diameter and filament moisture content can necessitate adjustments for optimal results.

Working Principles

At its core, you can think of Pressure Advance as a smart way the printer adjusts filament flow just before speed changes, somewhat like dynamically altering retraction during a print move.

Tools & Materials

• Computer with PrusaSlicer installed
• Vision Miner 22IDEX V4 connected and operational
• Filament (the specific type you are calibrating)
• Calibration model (e.g., a simple cylinder or 20 mm cube .stl)

Pre-checks

• Before printing, run Print Check List
• Have a suitable calibration model file ready

Step-by-Step Instructions

1. Understanding Pressure Advance Effects

Pressure Advance primarily affects two visual aspects of your print:

• Corners: Properly tuned Pressure Advance results in sharp, well-defined corners. If corners are rounded, Pressure Advance might be too high. If corners have excessive bulging or overshoot, it might be too low.
• Seam: The seam is where the printer starts and stops extrusion on each layer.
  • If the seam bulges outward significantly from the print surface, Pressure Advance is likely too low (or off), causing excess pressure release at the layer end.
  • If there is a gap or depression at the seam, Pressure Advance might be too high, retracting too aggressively before the layer change.

2. Locating the Pressure Advance Setting in PrusaSlicer

The Pressure Advance value is set via custom G-code within the filament profile:

1. Open PrusaSlicer.
2. Go to the Filament Settings tab.
3. Select the filament profile you wish to adjust from the dropdown menu.
4. Navigate to the Custom G-code section in the left-hand panel.
5. Locate the Start G-code text box.
6. Look for a line starting with M572, for example M572 D0:1 S0.045. This command sets the Pressure Advance value. The number after S differs from profile to profile, so do not expect the same value in every filament. If the line is not present, the printer will use its firmware default or none if not configured.

3. Baseline Values and Adjusting for Nozzle Size

Our default profiles often use a Pressure Advance value suitable for common materials with a 0.4 mm nozzle.

• Default (0.4 mm Nozzle): A typical starting value for many plastics (like PLA, ABS) is S0.035.
• Larger Nozzles (0.6 mm): Pressure effects are less pronounced with larger orifices. You should decrease the Pressure Advance value significantly. Try starting around S0.01 or even disabling it completely by setting it to S0.0.
• Very Large Nozzles (0.8 mm and up): It is generally recommended to disable Pressure Advance entirely for very large nozzles - set to S0.0.

Our profiles already do this selection for you. Instead of a single M572 line, they carry a conditional expression that reads the nozzle diameter and picks the matching value, so the same profile stays correct when you swap nozzles:

Reading the conditional, and editing the right part of it

This is where people get it wrong, so it is worth slowing down. The expression is two lines, one per toolhead, and each line contains four alternatives, one per nozzle size. It looks dense, but it is only saying "look at which nozzle this toolhead has, and use the matching number".

{if nozzle_diameter[0]<0.4}M572 D0 S0.049{elsif nozzle_diameter[0]==0.4}M572 D0 S0.035{elsif nozzle_diameter[0]<=0.6}M572 D0 S0.0105{else}M572 D0 S0{endif}
{if nozzle_diameter[1]<0.4}M572 D1 S0.049{elsif nozzle_diameter[1]==0.4}M572 D1 S0.035{elsif nozzle_diameter[1]<=0.6}M572 D1 S0.0105{else}M572 D1 S0{endif}

Decoded, each line means:

And the two addresses you need to keep straight:

• D0 is the left toolhead (Tool 0), D1 is the right one (Tool 1). The first line handles D0, the second handles D1.
• nozzle_diameter[0] and [1] are the nozzle sizes of those same two toolheads, taken from your printer profile.

4. Calibration Procedure

Finding a value: the Pressure Advance test

Do not guess your way there one print at a time. Use the dedicated test in Material Tuning. It prints a teardrop shape where the Pressure Advance value climbs from bottom to top, so the transition from blobs to gaps is visible in a single part and you can read the best value straight off it.

For most materials the useful range is roughly 0 to 0.15, and the test sweeps across it. Take the value you read off the print and put it into the matching branch of the conditional described above.

Confirming the value: print a cube

Once the test gives you a number, verify it on a shape that shows both failure modes at once. A simple cube is ideal, because it gives you two things to judge:

• The corners, where the nozzle changes direction sharply. This is where too little compensation causes overshoot and bulging.
• The seam, where each layer starts and ends. This is where too much or too little compensation is easiest to see.

Position the seam in the middle of a wall rather than on a corner. On a corner the seam hides in the geometry; in the middle of a flat face you can see exactly what it is doing. In PrusaSlicer this is Print Settings > Layers and perimeters > Seam position.

Print the cube with your candidate value in the M572 branch for the nozzle you are using, then judge it against the criteria below.

1. Evaluate: Carefully examine the corners and the seam of the printed model.
   • Seam Bulging / Overshooting Corners? → Pressure Advance might be too low. Increase the S value slightly (e.g., from 0.035 to 0.045).
   • Seam Gap / Rounded Corners? → Pressure Advance might be too high. Decrease the S value (e.g., from 0.035 to 0.010, or from 0.01 to 0.0 for larger nozzles).

2. Iterate: Modify the M572 S<value> in the filament's start G-code, re-slice, and print again.
3. Save Profile: Once satisfied, save the modified filament profile.

Ready-made calibration files

You do not have to model the cube yourself. These are the files we use, already set up with the seam placed for inspection:

Troubleshooting

FAQ

Support

If you could not find an answer here, reach out to our support team.