This Is Just A Test: Breaking Things

A project log for Mechanized Prosthetic Foot

The purpose of this project is to design and build a fully mechanized prosthetic foot that is more accessible than current solutions.

AractapodAractapod 09/14/2016 at 23:340 Comments

After printing the test samples the group used an Instron testing machine to gather data about the tensile properties of the proposed materials. Drawing the sample at 2.5mm/min provided valuable data about the materials being used in this comparison. The tensile data gathered shows the stress over strain curves for the six samples tested. The group concluded that the PLA sample tested at 75% infill provided the most strength, but proved to be very brittle.

With the tension data gathered the group continued to research the compression characteristics of the materials. Due to not having the proper fixtures needed to test compression on the instron machine the group was forced to use a hydraulic compression machine. This machine utilizes hydraulic pressure and manual controls to modulate the testing surface. The data gathered from testing on this machine provided the group with only the maximum compression values of the samples.

The compression data again proved that the PLA material printed at 75% infill was the strongest. Using ABS allowed the group to print more durable models in a very short period of time, which was the most ideal choice when choosing a material.