Starting point

Temperature tower

Print a tower with five bands across the range, keeping flow at 1.00 and cooling fixed.

Five bands: 240 · 245 · 250 · 255 · 260 °C

Print with the enclosure closed and the chamber stable; a draught changes the result.

Read the tower in this order:

• Layer adhesion — snap each band. A clean, strong break above the band is good; a brittle, flaky break means too cold.
• Stringing — look at the gaps between features. The cooler bands should have less.
• Surface and bridging — glossy, blobby or drooping bands are too hot.

Pick the lowest band that still gives strong layer adhesion and a clean surface. Lower is better for stringing and overhangs, as long as the part is not brittle.

Flow test

Print a single-wall cube with two perimeters, no top or bottom layers, and your normal line width. Measure the wall in several places with calipers.

extrusion multiplier = target wall width ÷ measured wall width

For a 0.45 mm line width, a measured 0.48 mm wall means 0.45 ÷ 0.48 = 0.94. Set the multiplier to 0.94 and print the cube again to confirm.

Change only the multiplier between tests. If the wall varies by more than 0.03 mm, fix mechanical issues (loose belts, a worn nozzle, inconsistent filament diameter) before tuning further.

Retraction starting points

Print a retraction test with two towers 30 mm apart. Increase the retraction distance in 0.2 mm steps until stringing stops, then back off one step to protect layer adhesion.

• Direct drive: 0.6 mm at 30 mm/s.
• Bowden: 5 mm at 40 mm/s.

Then print a 20 mm calibration cube and a 10 mm hole. FDM holes usually come out small; add 0.05–0.15 mm of hole compensation rather than scaling the whole part.

When is it good enough?

• The temperature band snaps cleanly and has no stringing.
• The measured wall is within 0.02 mm of the line width.
• Two towers 30 mm apart print with no visible strings.
• A 20 mm cube measures 20.0 ± 0.1 mm.

Tools that help

FAQ