What chamber temperature does ABS actually need?
An enclosed chamber at 45 to 60 °C. That’s the range on Bambu Lab’s ABS data sheet, and its slicer guide saves 60 °C for large, dense parts prone to warping. Prusa asks only for an enclosure and a bed of at least 100 °C. Either way, the air stays under ABS’s glass transition, 101 °C on Polymaker’s data sheet.
- Corner lifts off the bed
- Center stays warm and flat
- Heated bed
Chamber temperatures and what they do to ABS
The rows run from the coldest air to the hottest reference point. The first is the only warp test: Ramian, Ramian and Dziob printed ABS (acrylonitrile butadiene styrene) blocks on an open Ultimaker 3 with a 90 °C bed, then measured the lift at each vertical edge with calipers. Everything else comes from the makers’ guidance and data sheets.
| Chamber air | Source and setup | What the source reports for ABS |
|---|---|---|
| About 20 to 30 °C, open printer | Ramian et al., no enclosure, 90 °C bed | Average corner lift of 0.86 mm on a 30 mm cube and 4.27 mm on a 120 mm bar, which bent into a “banana-shaped defect” |
| Enclosed, no set figure | Prusa knowledge base | ABS “requires printer enclosure” with “a higher ambient temperature” and a bed of at least 100 °C |
| Enclosed, no set figure | Polymaker PolyLite ABS data sheet | “Closure Chamber Needed (ambient temperature)”, with a 90 to 100 °C bed |
| Enclosed, heater off | Bambu Studio default for ABS | Heater off for “other normal prints”, because “the air filtration will get worse” when it runs |
| 45 to 60 °C | Bambu ABS data sheet | The recommended chamber range, alongside an 80 to 100 °C bed |
| 60 °C | Bambu Studio guide, for large or high-infill parts | “Reduced warping”, better dimensional accuracy and, on some models, stronger layer bonds |
| 84 °C | Bambu ABS data sheet, ISO 75 at 1.8 MPa | Heat deflection: a printed bar bends under a set load |
| 94 °C | Bambu ABS data sheet, ISO 306 | Vicat softening: a loaded needle starts to sink into the plastic |
| 101 °C | Polymaker PolyLite ABS data sheet, differential scanning calorimetry (DSC) at 10 °C/min | Glass transition; Ramian et al. give about 105 °C for ABS in general |
None of these sources measured lift in a heated chamber. The enclosed rows are the makers’ advice, not test results.
Why warmer air stops the corners lifting
ABS warps on the way down, as it cools from its glass transition to the air around it. Ramian et al. put the damage “during the transition from glass transition temperature to chamber temperature.” Bambu’s guide blames the same gap. A high glass transition and a cold room leave “significant internal stress” in the part, which then shrinks and warps.
Ramian et al.’s thermal camera showed where that stress builds. On the open printer the bed sat near 90 °C, the middle of the part at 60 to 70 °C and the chamber walls at 20 to 30 °C. The edges ran cooler than the middle, and after two hours the top of a tall part was mostly below 50 °C. “This temperature gradient created stress and peeled off the cooler corners,” the authors wrote.
Their fix was less airflow, “by closing it or by printing in a heated chamber.” Warmer air shortens the drop from the glass transition, so less shrinkage piles up at the corners. Even 60 °C air sits 24 °C below the heat deflection figure on Bambu’s sheet. Bambu’s chamber heater setting runs from 40 to 60 °C.
More heat is not free. A hot chamber lowers how much Bambu’s activated-carbon filter can soak up. Above 45 °C, Bambu also blocks loading low-temperature filaments such as polylactic acid (PLA) and PETG (glycol-modified PET), since they can soften and jam the extruder. Prusa adds that the heat inside an enclosure can deform the printer’s own plastic parts, such as the fan shroud.
How to check it on your own print
- Measure the air, not the bed. Hang a thermometer in the chamber, clear of the bed and the nozzle, and read it mid-print. The bed warms the chamber only indirectly, so its setting tells you little about the air.
- Preheat without a heater. In a cold room, Bambu’s advice for its X1C and P1S is to run the bed at its maximum for 15 minutes before you start. That warms the enclosed air.
- Print a long test bar. In the Ramian tests, length drove lift more than height. Print a bar as long as your real part, then measure the height at each corner and at the tallest point with calipers. The difference is your lift.
- Cut the shrinkage load. Dense parts shrink harder. On ABS, Bambu suggests infill at or below 50 percent, walls at 6 or fewer and glue on the plate.
- Without an enclosure, add a draft shield. That’s Prusa’s fallback: PrusaSlicer prints a thin wall around the part that keeps it “slightly warmer.” If you ventilate the room, Prusa also warns against letting a draft blow across the printer.
Sources
- Bambu ABS Technical Data Sheet V3.0, Bambu Lab (accessed September 23, 2026)
- Bambu Studio chamber temperature setting, Bambu Lab Wiki (accessed September 23, 2026)
- ABS / ASA / PC Usage Guide, Bambu Lab Wiki (accessed September 23, 2026)
- ABS, Prusa Knowledge Base (accessed September 23, 2026)
- PolyLite ABS Technical Data Sheet, Polymaker Wiki (accessed September 23, 2026)
- Thermal Deformations of Thermoplast during 3D Printing: Warping in the Case of ABS, Ramian, Ramian and Dziob, Materials (2021) (accessed September 23, 2026)