Design Rationale
The claws are designed to hold the shirt up before the Elsa begins putting on her shirt. A device
was needed which would not only support the shirt in order for the user to begin the process, but
also to allow the shirt to be released at a later stage of the process. The user demonstrated
adeptness in fitting her arms through the shirt as it was mounted on the claws during user testing.
While we were not able to successfully test the user’s ability to fit her head through the mounted
shirt without assistance (see Appendix E: User Testing Summary) we decided to continue using
the claws after deliberation.
Pulley System
Design Concept
The two pulleys (see Figure 11) are attached to the door assembly above the Shirt Horn claws.
They are positioned so that one end of the rope is attached to dynamic claw and the other is
positioned in front of the user. Each pulley has a diameter of 5.5 inches and a central opening of
1.125 inches. A wooden axle with a diameter of 1 inch goes through each of the central holes and
allows the pulleys to rotate.
Figure 11: Pulley System
Design Rationale
The pulleys are an obvious choice to assist Elsa in taking off her shirt. During the initial user
observation summary, Elsa was tasked with pulling on an iPhone cable as hard as possible,
simulating pulling on a rope in a pulley system. Since she accomplished said task with
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