WOBBLlid.py

Will this long ABS lid warp or lift its corners when I print it on an open printer?

Print warp report
2026-10-15 18:57
FAILS

Warps 3.81 mm off flat, over the 0.8 mm tolerance, with a corner lifting 3.81 mm when it comes off the bed.

flatness
3.81 mm
tolerance
0.8 mm
corner lift
3.81 mm
stress on the bed
15.8 MPa

Confidence medium

  • process estimate: the warp model is fitted to 48 measured ABS plates (median error 9%, worst 39%)

Simulation

The part after it comes off the bed, warp drawn larger, lift marked
The part after it comes off the bed, warp drawn larger, lift marked
Height of the face that sat on the bed, from its best plane
Height of the face that sat on the bed, from its best plane
Stress the print carries while held on the bed
Stress the print carries while held on the bed

Checks

statuscheckresult
passmesh convergenceflatness after release settled: 3.79 -> 3.81 mm over 2 meshes, last change 0.4%
passhand calculationa free plate 14.5 mm thick with the same shrinkage curves to 0.557 1/m, 3.62 mm over its 220 by 60 mm footprint; the solve gives 3.81 mm (1.05x)
passbalance on the bedthe shrinkage loads itself, so the bed's pulls and pushes cancel to 1.6e-08 of 9654 N
passunits and sanitylocked in shrinkage up to 0.72%, largest movement 7.57 mm on a 220 mm part
failflatnessthe face on the bed comes off 3.81 mm out of flat, its corners up to 3.81 mm, against a 0.8 mm tolerance
infobed peelwhile it prints, the corner at (220, 0) mm pulls up on the bed with 336 N, about 0.365 MPa over its 34.2 mm patch

How to fix it

Print in an enclosure near 45 C
The locked in shrinkage runs from the glass transition down to the air around the part, so air at 45 C instead of 25 C cuts the warp to about 2.86 mm.
Print it in PETG
PETG locks in 0.33% against 0.72% here, for about 1.75 mm of warp, if its strength and heat resistance suit the part.
Add a brim and keep the bed hot
While it prints a corner pulls up with about 336 N. A 5 to 8 mm brim gives that corner more bed to hold, and a bed near 100 C keeps the first layers soft and stuck, which this model assumes; it does not change the warp after release.

Assumptions

  1. Wobbl guessed: bed temperature not given, so Wobbl assumed 100 C, usual for ABS.
  2. Wobbl guessed: no enclosure mentioned, so the part cools in open air at 25 C.
  3. Wobbl guessed: print direction not given, so the part prints the way it is drawn, layers along z.
  4. Wobbl guessed: infill not given, so Wobbl treated the part as solid, as the calibration plates were.
  5. ABS: E 2200 MPa, Poisson's ratio 0.35, expansion 90 per million per C, glass transition 105 C. Tg typical of ABS (Stratasys ABSplus lists 108 C); warp ramp fitted to Armillotta et al. 2018.
  6. Printed with layers along z, into surroundings at 25 C (an open printer).
  7. Each layer locks in the shrinkage from the glass transition to the surroundings, up to 0.72%, rising from nothing at the bed to all of it 11.5 mm up, a profile fitted to the 48 ABS plates of Armillotta et al. 2018 (R2 0.94).
  8. The part is held flat on the bed until the print ends, then released; corners that peel during the print are not followed, so a part that lifts early warps more than this.
  9. The part is solid.
  10. Supports, the seam and the cooling fan are not modeled, and the layers are treated as one bonded solid.
  11. Predicted 9 min for the first 2 mesh levels against a budget of 10 min, so the meshes were left as they were. It solved 2 levels of 26,082, 52,070 nodes in 3 min. The budget can be raised with --budget.