Temperature Tower

A temperature tower is a fast way to pick the best nozzle temperature for one specific filament on your specific printer. You print one model that automatically steps temperature by height, then choose the coolest section that still has good layer bonding and clean surfaces (not stringy, not saggy, not under-extruded).

TL;DR

Print a temperature tower that changes nozzle temp by height (5–10 C steps), then pick the coolest section that still has strong layer bonding and no under-extrusion. Stop and lower temperature if you see smoke, harsh odor, or dark/brittle output.

A quick visual map of the main decisions behind a temperature tower.

When a temperature tower is worth doing

Run a tower when you change filament type (PLA, PETG, ABS/ASA, TPU), brand, or even color (pigments change flow). Also re-run after hardware changes that affect heat or airflow (new hotend, different nozzle material like hardened steel, different part-cooling duct/fan), or when you make a big speed/volumetric-flow change. If stringing or weak bonding appears “out of nowhere,” first confirm basics like dry filament, a clean nozzle, and stable cooling, then use a tower to re-establish the best temperature.

Setup (keep everything else constant)

  1. Start with the filament maker’s recommended temperature range as your test window.
  2. Use one spool for the entire tower and make sure it is reasonably dry (wet filament can make every section look worse and hide the real temperature sweet spot).
  3. Hold other variables steady: layer height, line width, speed, retraction, fan behavior, and flow/extrusion multiplier.
  4. Choose a tower that labels each temperature segment and includes features that reveal problems: overhangs, bridges, small posts/gaps (stringing), and fine text or corners (detail and overheating).
  5. Pick step size: 10 C steps for a first pass; 5 C steps to fine-tune around a winner.

Slicing and printing (make sure temps really change)

  1. Enable temperature changes by height using your slicer’s calibration tool, a post-processing script, or manual G-code (each segment should have one stable temperature).
  2. Set the start and end temperatures to cover the full range you want to evaluate, staying within filament and hotend limits. (Examples vary widely; follow the spool/spec sheet rather than copying numbers.)
  3. Use normal part-cooling for that material and keep it consistent through the tower unless your goal is specifically to study cooling effects.
  4. Let the tower finish and cool before judging; some artifacts (especially stringing and surface sheen) change as the plastic cools.

How to pick the best temperature segment

  • Stringing: prefer cooler segments, but only if the extrusion remains consistent (no gaps, no skipping, no rough under-extrusion).
  • Overhangs/bridges: look for the least sagging and the cleanest bridge lines and edges; too hot droops, too cool can snap or look patchy.
  • Surface and details: avoid blobby corners, swollen text, and overly glossy “melty” surfaces (too hot), and avoid matte/grainy, thin, or underfilled surfaces (too cool).
  • Layer bonding: gently flex a thin wall/tab or try to snap a narrow feature; reject temperatures where layers split easily (too cool) even if the surface looks nice.
  • Overall balance: choose the segment that looks good across multiple features, not the one that wins only one metric.

Lock it in (and verify on a real part)

Set the chosen temperature as the default for that filament profile, then validate it on a small “real” print that matches your typical geometry (walls, small details, overhangs). If the tower shows a narrow sweet spot, run a second tower centered on that range with smaller steps to confirm repeatability.

If your tower results are confusing

All sections look stringy

Likely cause: Moist filament, lots of travel over open gaps, or retraction/cooling not tuned

Fix: Dry the filament and re-run. If it’s still stringy, tune retraction and part cooling separately; temperature alone may not fix it.

All sections look under-extruded or rough

Likely cause: Partial clog, printing too fast for the tested temperatures (too much volumetric flow), or an extrusion setup issue

Fix: Clean/replace nozzle and check the filament path. Re-run the tower at a slower speed (lower volumetric flow) to separate “too cold” from “too fast.”

Only the hottest sections look bad (blobs, droop, glossy, loss of detail)

Likely cause: Temperature is higher than your cooling and feature size can handle

Fix: Choose a cooler segment. If you must run hot for strength, add cooling, slow down small layers, or increase minimum layer time.

Only the coolest sections look weak, have gaps, or layers split

Likely cause: Temperature too low for proper melting and bonding at your current speed

Fix: Choose a hotter segment or reduce speed/volumetric flow and re-test to keep bonding while staying as cool as practical.