Car Test

thingiverse

Some PETG will still warp in a hot car (looking at you, KVP!), but before you print something useful for your car and have it melt, wouldn't it be nice to make sure it holds up ahead of time? Enter the Car Test. Print one of these bad boys off, flip it upside down, and let it sit under your front windshield for a while. If it deforms, you'll know just by looking at it. And if you're not sure, a straight-edge of any sort will tell you (unless your bed is super warped, in which case, get a better bed... looking at you, Creality!) If you're still confused, there's a 42-second YouTube of how it works here: https://youtu.be/kqSLUHOnWW8 The flat part is 1mm thick, so 0.2mm or 0.25mm layer heights work best. Use enough shells to remove the desire for a slicer to attempt infill (3 for 0.2 layer height, 2 for 0.25 layer height -- any higher is wasted on the legs).The goal is to have the bridge section out of shells *only*, with no infill, for maximum stiffness. Infill at the lowest amount that you're comfortable with the shells on the legs printing correctly. No point in wasting *too* much filament in testing things, right? For a full list of PETG that passes (and fails!) the car test, please see here: https://shep.zone/3d/filament This list is community-driven, but due to the nature of anonymity and the potential for a filament manufacturer to bias the results, I can only add failed car test results to the list from people that find me through the above link.