Dialling In Your Temperature Settings

James H.

Not All Filaments Are Created Equal

Here's something that surprises many beginners: even two spools of PLA from the same manufacturer, in different colours, can print optimally at temperatures 5–10°C apart. The pigments used to colour filaments are not inert, they change the thermal properties of the base polymer in meaningful ways. Red and black pigments, for example, tend to require slightly higher temperatures than natural or white filaments. Carbon black (used in black filaments) actually improves thermal conductivity, subtly changing how the plastic behaves in the hotend.

The manufacturer's recommended temperature range (printed on the spool label) is a starting point, not a finished answer. The range for most PLA is 190–230°C — a 40-degree window. Where within that window your specific spool prints best is something you need to discover empirically, and the temperature tower is the systematic tool for doing so.

What Is a Temperature Tower?

A temperature tower is a calibration model with multiple distinct segments (usually 5–8°C apart) that prints at a different temperature for each segment. The model includes features that reveal temperature-sensitive behaviour: bridging sections, overhangs, fine towers, corner sharpness. The slicer's post processing feature (or a specific plugin) inserts temperature change G-code commands at the correct layer heights. The result is a single print that shows you, side by side, how the filament behaves at each temperature in its recommended range.

Print the tower a light colour (white, light grey, or natural) so all the surface details are visible. After printing, examine each segment carefully. Look for: stringing (hairs between towers, usually worse at higher temperatures); overhang quality (cleaner at lower temperatures with good cooling); bridging quality (flat vs droopy); and surface texture (look for the temperature that produces the smoothest, most consistent walls).

Analysing and Applying the Results

The "Goldilocks zone" is where all these factors are best balanced. Often this means overhangs and bridges are cleanest, stringing is minimal or absent, and the surface finish is consistent. This temperature becomes your starting point for all future prints with that specific spool. Write it on the spool with a permanent marker, you'll thank yourself six months from now when you load it again.

A well chosen print temperature underpins everything else you'll tune. Retraction tuning results depend on temperature (a too-hot nozzle oozes too freely for any retraction to control). Pressure advance calibration assumes a stable temperature. Flow rate calibration results shift with temperature. First, complete the temperature tower, lock in the temperature, and then proceed to the other calibrations. Use quality, consistent filament from OzFDM, batch consistency means your temperature calibration stays accurate across multiple spools of the same product rather than needing complete recalibration every time.

Material-Specific Temperature Considerations

PETG is particularly temperature sensitive; a 5°C difference dramatically changes stringing behaviour. ABS is less sensitive within its range, but the upper limit matters; too hot causes poor bridging and bubbling. TPU generally prefers the higher end of its range for smooth flow, but excessive temperature causes yellowing. For every new filament type or brand, run the tower before committing to a serious print. The 45-minute investment of a temperature tower saves hours of troubleshooting failed prints.