Our final machine was quite similar to the original design, but it had some definite differences. One such was the sliding method of the long arm. Initially, we planned on using a sliding dovetail bearing, but in the end we milled a channel in a steel arm and slid the arm along bolts. The Rack and pinion used to drive the extension remained the same.
The Worm Gear drive didn’t change until it was too late. The worm was under-constrained and we had some deflection issues, where the arm’s force caused the worm gear to deflect the worm out of the threads, causing stripping. We finally constrained it properly, but our intermediate constraint was poorly made and misaligned due to time limitations (we ignored this problem for far too long) and caused binding issues. This made our worm gear, which we relied on for a great deal of torque, to be seemingly weak and unable to lift any balls at all. At the very least it still prevented back-driving…
Our baseplate, mounts, and uprights were essentially identical to the original design. These parts were simply manufactured and used as initially intended. If the original design had been better, the need to add more in addition to the planned mounts and constraints would not have been needed. However, we were forced to add more stuff as the manufacturing went on, and we ended up with an over-constrained worm and a poorly constrained pinion drive.
The machine’s performance was poor, as earlier stated. The setscrews in the pinion stripped completely, and the worm was rendered near-useless by the binding issues. We believe that our concept was sound, and that if the design for the constraints were better, the machine would have performed extremely well and been very competitive in the arena competition.
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