Week 10

     During class this week, we met with Dr. Gordon to discuss our progress on the project and then glued the bearings to the "arm" of the brace so that they did not move around. We believe that this was one of the reasons why we had issues last week while testing the new dual system.
     Once the glue had dried, we tested the dual system using the force plate. Isaac was also available for testing, so the leg brace was worn by its intended user (the current leg brace was customized to fit Isaac's leg). The glue seemed to help immensely, as the system worked far better this week.
     As stated in previous blog posts, our target is 140 N, as our research has shown that this amount of force should be sufficient to completely prevent bone density loss while in space. We were able to reach and exceed this amount of force during testing. The results for some of the testing we did can be seen below. (All of the data was gathered from Isaac standing vertically on the force plate.)

Data from testing summarized in a table. As can be seen, we generated approximately 205 N of force for some of the trials.

The data in the table was obtained from saving the data points during test and graphing them in a plot. This allowed the peak-to-peak force to estimated.

As can be seen from the two plots, the peak-to-peak force for different motor speeds (given in "Arduinos") may be estimated.

     This testing showed that we can reach our target force, which is encouraging. However, one of the issues we ran into was that the system was a bit uncomfortable to wear. We will look into addressing this, whether we need to make the brace more comfortable (such as by adding foam as a cushion) or decreasing the amount of time that the system needs to be worn during each use. 

     We also revised and reprinted the motor casing this week. The previous case had very tight tolerances, so the spinning brass masses were very close to the side/wall of the casing. We found that when we put the lid on the original case, it would push the sides in, which would interfere with the spinning masses. Our second version is slightly bigger to accommodate this, and has a shorter lid to help avoid the issue as well. The second revision of the case can be seen in the images below. (We did not have a chance to use the new casing as it was printed at the very end of the week. It will be incorporated into the system at the beginning of Week 11).

View of the new motor casing with the lid off.

The motor casing with the lid on.