After the first compression test, we did a second one. This time we chose a 50% infill for all the printed cubes, but with different pocket sizing. The pocket sizing starts at 0 mm and ends at 2 mm, with increments of 0.2 mm over a total of eleven cubes. In the pictures below, you can see the different pocket sizes. The numbers indicate the pocket sizes of the cube.
Looking at a different pocket size is rather interesting because you will create the same infill percentage with a different pocket size. In the pictures below you can see how the pocket size influences the pattern. It seems logical that a bigger pocket size means more area to move into when it gets compressed. Conducting this test will show us whether that is true and how the difference in pocket sizing will influence the printed products.
The cubes have been tested by the same machine, as the last post with the same load range. First test round was done with a load of 0-2000N and the second with a load of 0-4000N.
The results of the test can be seen below.
In the 4,000N test, you can see that the pockets for 0.0mm – 0.6mm has little influence on the compression. The 0.4 mm is hidden behind 0.6mm line. Starting from 0.8mm it starts to have some influence. While the pockets are bigger, the amount force that is needed also increases. 1.0mm becomes a less curvy line, meaning that the cube becomes stiffer.
From 1.2mm there is something weird happening, it is the most flexible cube together with the 1.4mm cube. The odd thing is, that 1.0mm is pretty rigid but if you increase the cube by 0.2mm it loses a lot of its stiffness.
The cubes become more rigid from 1.6mm till 2.0mm. A possible reason why the cubes become stiffer from 1.6mm till 2.0 mm pocket sizing is the internal structure. The cubes get a new structure when you increase the pocket size to more than 1.6mm. Cura also does not recommend the user to go above this threshold number, in this case 1.0mm. The new (extra) structure might distribute the force more evenly and results in less compression.
The cubes gets deformed quite a bit after each test, they do get their shape back after a few minutes, we have not measured this yet. Measuring the deformation might give us rather useful data. Especially for insoles as they will be loaded at all times when they are in use.