Table 6: Downward force (one time jerks) applied by Elsa over 7 trials
Trials
Force applied (lb)
1
3.2
2
3
3
2.8
4
2.5
5
2.2
6
3
7
2
Average:
2.67
Analysis, Conclusions, and Limitations
Analysis of Results and Conclusions
Shirt horn: The data shows that, given the device works the way it is designed to, the time
taken to put the shirt on is as average of 15.2 seconds. This absolutely meets the
condition that it needs to take less than 2.5 minutes as stated in the mission statement.
Pulley system: The figures indicate that the average force that Elsa can apply downward,
regardless of whether it is a onetime jerk or a sustained pull, is approximately 1.5 to 2.5
lbs. This, as seen in performance testing, is enough force to pull one’s shirt off one’s
body.
Limitations
Our mockup for the Shirt Horn was slightly damaged while carrying to the RIC. As a result, the
claws came loose and therefore were unless to support the tshirt resting on them. We had to
manually support the tshirt with our hands while tests were being conducted, and this may have
led to some skewed readings. Also, the tshirt that we were using with the shirthorn was very
large; far larger that her usual school uniform tshirt. It therefore may have been easier to put on.
However, a counterargument is that she was wearing a tshirt inside while putting the big tshirt
on, which she won’t be doing when she puts her school uniform tshirt on.
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