Performance Testing II
This session was conducted to determine the optimal material to use for the rope in our pulley
system.
Date: February 20th, 2016
Time: 3:00 pm 4:00 pm
Location: Bobb Hall
Purpose
Are there any standout materials that would work best in our pulley system?
Methodology
1. A variety of strings including a thin rope (0.25” diameter), yarn, and thread were tied to a
metal bar that was left to dangle.
2. On the dangling side of the strings, forces were applied via a 15 lb weight to analyze how
the different materials would react (Figure 24 and Figure 25).
3. Each of the materials were pulled by the forefingers of a group member for 10 seconds
and the ease with which the material was pulled was observed. Table 7 shows results.
Results
Table 7: Performance Testing II results
Characteristic
Thin Rope
Yarn
Thread
Response to 15lb
force
Maintains firm
structure (Figure 24)
Yarn rips apart
(Figure 26)