Work to be Completed over Christmas Break
Silicone Boot
After a horrible failure, and being backed into a corner by his teammates and advisor, Evan will be spending Christmas Break constructing a new silicone boot. This hideous attempt at engineering can be found here. Additional information, including a masterful design and implementation of the silicone boot mold, can be found at Evan’s Wiki Report.
Complete Silicone Boot
You can see from the picture below that a complete boot was successfully constructed, thus allowing Evan off the hook.
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| Actuator Assembly Boot | Actuator Function |
Finger Material
After constructing a CFP, it was determined that the material used for the finger was too brittle. An evaluation of this CFP can be seen Here. Tyson is currently researching other materials that could be applied to the finger structure. More information on this can be found at Tyson’s Wiki Report.
SMA Spring Calculations
After benchmarking was completed, it was discovered that the required force of 10 newtons was not adequate. The previous design teams calculations (Last Year’s Team Robotic Hand 2005-2006 Home Page) did not meet the force generated by an average human hand. The new force requirement is 40 to 60 newtons. The background information can be seen at Bryan Adams Wiki Report. A new SMA spring will be made out of untrained Nitinol SMA wire.
Calculations for a new SMA Spring can be found in this Excel work sheet and if you do not have Excel, look at this photo.It is nearly impossible to find information about Young’s Modulus and spring constants for SMA wire. Preposterous assumptions were made to estimate the needed dimensions of the new spring. Rob Poulsen will be helping with the calculations to refine exactly what we need and how we are going to calculate it. Essentially, we need to determine the force created by the SMA spring when it changes between phases. More information about Robs contribution can be found at his Wiki report.
SMA Spring Calculation
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| Initial SMA Spring Calculations |