Senior Design 04-05: Team 13

October: We packed a tire ourselves to see how they behave when they're full of dirt. This one held its dirt remarkably well, even 6 months later in March.

The big moment: can the crane hold Andrew if he uses it like a tire swing?

Shortly after this initial half load test, but before we performed a full load test, an error was found in one of our calculations, putting testing on hold until we could work the problem out. Out of curiosity, we tested our old design with a heavy object to check for yielding, and our prediction from the miscalculated quantity proved to be legitimate, prompting a redesign.

Our redesign featured a beefed up A-frame, and beefed up top connection, a beefed up truss, and beefed up pin joints. All of these things made our crane much more stable and strong.

After these design changes were fabricated, we lifted the same heavy block that had caused a failure before, and the crane had no difficulty lifting it. The swivel and roller track motion worked well during the testing with this block as well.

To test the crane for creep resistance, a packed tire was hung from it, and the distance from the tire to the ground was kept track of over the course of a few days. After 4 days of holding this tire, the crane had not sagged at all!