1/12/2014 Day 8: Beginning of Week 2 and Exiting the Conceptual Design Phase

Today we were back to a full group, since the VEX Competition was finished and emergency work was taken care of the day before.  Our big decision today was whether or not to go with a puncher/jaws intake and shooter assembly, or to go with the intake roller that pivots with a catapult.  After reviewing the spreadsheet, the decision was inconclusive (slight majority for the independent systems, but not entirely conclusive), so the "Committee of Public Safety" (the three members, including me, and two mentors the team voted on to become the official tie breakers) voted 4-1 (split mentors, unanimous students) to go with keeping the intake roller and shooter/launcher separate.  As we decided on the catapult, we split back into our original groups, so I went back to work on the catcher.

Shooter

Today a group of 4 students and 1 mentor designed the shooter, which would be a pneumatic catapult, rather than a surgical tubing catapult, due to the small amount of space a pneumatic (flat) catapult takes up (picture below), as opposed to the spring powered shooter, which would have a tower attached.

By the end of the day, drawings for all of the gusset plates and the shooter as a whole were finished, ready for manufacturing tomorrow.

Intake

Today the intake team figured out how to fold the intake system in and out, so it can start within the frame perimeter, but extend outward the 20" it needs to.  The intake basically just required several pieces of square tubing, ABS sewer pipe, two pistons (one for each side), and coarse plastic/paper material.  The coarse material on a plastic pipe roller has been shown to be very effective, especially with picking up somewhat compressible objects.

Drivetrain

Not a lot was done with the drivetrain today, and was mostly worked on by programmers to make it drive.

Catcher

Today was a major advancement for the catcher.  As we now have a general concept of how it can be actuated, we worked on possible material to use for it.  After thinking about netting for previous days, we took a slightly different approach.  As we had lots of conduit, we decided to play around with that.  As a bumpers discussion was going on previously, pool noodles quickly came to mind, as those are what are used for bumpers, so we slipped on a pool noodle on the conduit (shown below), and tested both conduit with pool noodles and without pool noodles.

As expected. the pool noodle worked well to dampen the impact from the ball, and much better than the conduit on its own.  This meant the idea with folding out sides would work, so that method of catching was now out of the conceptual design phase and well into the preliminary design phase.  The only other concept for catching was the folding out corners, which had to be prototyped a different day.

In addition to the new possible sides, the catching subteam worked on a frame that goes on top of the drive base, including the catcher.  Since there is not much space on the drive base to mount things, and it is preferred to not have to deal with mechanisms being mixed into electronics, the elevated frame is necessary as something to mount the subsystems onto, as well as keep everything above the drive base.  We designed the frame, with the main purposes of elevating everything and having something to mount things onto, and laser cut wooden gussets over the course of the day, as well as going out to buy parts (wood) for the frame.

Approximate times of working: 12:00 PM - 6:00 PM