Today, Monday the 31st of October, we did a last minute test on our prototype cubes (2 x 2 x 2 cm) with a Zwickmachine: a drawbench that tests materials on their tensile strength. By applying a pressure of 500 N in ~16 seconds on each of the test cubes and measuring the compression, we obtained data of the 5 cubes. Then we compared the data in order to draw a conclusion on which material and pattern will suit the saddle the best. The 5 test cubes:
The first test cube was a pink cube made of 100% hard material:
This cube compressed with 0,159 mm.
The second test cube was a blue cube made of 50% hard material:
This cube compressed with 8,045 mm.
The third test cube was a soft cube with a hard spiral pattern in it:
This cube compressed with 0,271 mm.
The fourth test cube was a soft cube with a hard circular pattern in it:
This cube compressed with 0,399 mm.
The fifth test cube was a soft cube with a 50% hard circular pattern in it:
This cube compressed with 9,460 mm.
From least to most compressable:
0,159 pink cube 100% hard material
0,271 spiral pattern 100% hard material
0,399 circular pattern 100% hard material
8,045 blue cube 50% hard material
9,460 circular pattern 50% hard material
The results were mostly as we expected and with this information we can conclude that a circular pattern consisting of 50% hard material in a soft cube is best to use for suspension. Sadly, we don’t know how this pattern will work on a big scale (we are afraid it will rip easily).
This experiment was conducted on a short notice and we were unable to use the findings in our final saddle. It did give us an idea about all the variables that have to be taken into account when it comes to pressure distribution. Further research is needed to find the best combination of materials and patterns for optimal suspension. For our final saddle we decided to use a mix of hard and soft material (in a circular pattern) because we know from previous prototypes that this allows suspension to happen and is also strong enough to bear a person.