Below is a brief discussion of how our initial plan changed over time, what those changes were, what caused those changes, and the result of those changes.
Our initial robot design was to have a large net to catch the incoming beach ball and have the ball launched using a sling shot that was driven by a cam system. The original net design did not change throughout the term and ended up working very well. The main difference between the initial plan and the robot we took to competition was the launching mechanism. Our original motor that we had selected to drive our cam system was not strong enough to pull back on the sling shot. Because of this, the robot was not able to launch the ball. We tried many different cam shapes and sizes came close to having a working system but in the end had to make a quick change to a pressurized air launcher that ended up working fairly well.
We spent a lot more time than initially intended on the 3D model of the robot and this put us behind for all the other aspects of the build.
cam launcher mechanism --> pvc air pressure tank for launching
transistor --> voltage larger than expected, had to add relay
solenoid valve draws more current than expected --> added a transistor and relay