Dimensional thermal test jig (for annealing)

thingiverse

This companion tool by LuckyPants allows you to position up to four dimensional calibration tools at a 45-degree angle inside an oven or thermal testing environment. I initially used it to assess how annealing my PLA-based parts enhances their heat resistance, specifically whether they could withstand being placed in a hot car. The design enables the weight of the part itself to apply pressure on its middle section. I printed mine using MakerGeeks PETG, but next time, I'll probably use PLA and then subject it to 80C for 40 minutes. Unfortunately, PETG didn't hold up as well as I had hoped under high temperatures. In addition to this jig setup, here are my notes from the experiment: Samples (each sample had a 20% gyroid infill and 0.20 layer height): * Brown Solutech PLA (which is mediocre and I expected poor results - but it performed better than anticipated!). * Yellow MakerGeeks HTPLA * Blue MakerGeeks PETG (this piece wasn't annealed) Test Environment: * A steam oven in Sous Vide mode allowed for precise temperature control and slow heating/cooling. * The PLA and HTPLA parts were annealed horizontally at 80C for 30 minutes. Initially, they were placed in a cold oven, then heated and cooled down inside the oven. * The PLA/HTPLA and PETG test pieces were positioned on the jig and heated in the oven at various temperatures. Each temperature was held for 30 minutes. The test temperatures were: 50C, 60C, 70C, 75C, 80C, 90C Findings: * HTPLA shrank by 1.7% in X & Y and expanded by 0.5% in Z during annealing. * PLA shrank by 3% in X & Y and expanded by 0.5% in Z during annealing. * PETG began to sag slightly at 60C, drooped to about a 15% angle by 70C, and was almost limp on the bottom of the test jig by 75C. * PLA showed minimal droop (1mm) by 70C but maintained its shape as well as HTPLA did under heat. * HTPLA didn't sag at any temperature. Conclusions: * If you can live with shrinkage, PLA performs almost as well as HTPLA. * HTPLA shrinks significantly less during annealing compared to regular PLA. * Annealed PLA has better high-temperature resistance than non-annealed PETG. Possible Further Research: * Test higher temperatures - I stopped at 90C because it was easy to test in my oven (and since I only need my parts to survive in a super hot car, which the internet says is around 75C).