PrintMath

PLA calibration: temperature tower and flow test

Two tests turn a PLA preset into settings that work on your machine: a temperature tower for bonding and surface, then a flow test for exact extrusion.

The default filament. Prints easily on almost any machine, holds detail well, and is cheap. It softens at low temperatures, so it is a poor choice for hot cars or functional outdoor parts.

Starting point

Nozzle190–220 °C
Bed50–60 °C
Drying45 °C × 4 h
EnclosureNot required

Temperature tower

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

Five bands: 190 · 200 · 205 · 215 · 220 °C

Read the tower in this order:

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.

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?

Tools that help

FAQ

What temperature should I print PLA at?

The usual range is 190–220 °C. Start in the middle and pick the final value from a temperature tower.

How do I calibrate flow for PLA?

Print a single-wall cube, measure the wall with calipers, and set the extrusion multiplier to target width ÷ measured width.

Do I need to dry PLA before printing?

Not usually. Store it dry, and dry it only if you see stringing, popping or a rough surface.