Step 14.17 — Generate and print the Ellis PA pattern¶
Step 17 of 36 · Chapter 14 — Calibration and tuning
(no image — the pattern and an annotated example are on Ellis' Pattern Method page)
Gather for this segment — steps 14.17–14.18 (~20 min)
Tools and consumables
- Prusament ASA, about 15 g
- good light
- loupe, optional
Parts:
- Prusament ASA, about 15 g · consumable
Do:
- Open ellis3dp.com/Pressure_Linear_Advance_Tool/ with nozzle 0.4, layer 0.2, ASA temps 260/110.
- Enable the acceleration-control option and set it to your external-perimeter acceleration, not your new
max_accel. - Sweep PA 0 to 0.10 in 0.005 steps and print it.
Check
Pattern prints cleanly with visible, distinct corner tests across the full sweep.
What you're looking at
Pressure advance compensates for molten plastic behaving like a spring in the nozzle: pressure lags the extruder, so corners under-extrude going in and over-extrude coming out. Ellis' pattern prints many corners across a sweep of values so the right one can be picked by eye.
Caution
If you leave the acceleration at the machine maximum the pattern will ring and the result is worthless.
Tip
if the extremes of your sweep both look equally bad, widen the range and re-run rather than guessing.
Source: Ellis' Print Tuning Guide — pressure advance, pattern method · Ellis' Pressure/Linear Advance tool