Our plan to gain new members for next year and get students interested involves showing off the robot directly, and so we are making a few modifications to increase show value. Because we are no longer limited to 8 motors, we have geared up our drivetrain and added an extra motor for each side. Once we have the controller set up, the robot should be much faster than it used to be. We also replaced the aluminum gears in the gear box for the scissor lift with chains and sprockets to make it more reliable. We are still having trouble setting up our wi-fi network to run our robot wirelessly. We need this to be able to do any sort of demonstration. We are working with the Tech officials at our school to help us do this, and are making good progress every day.
Now that we have been eliminated from the competition, we will begin repairing our robot and promoting the program within our school. Because we are such a small team, and Tyler and I are both Juniors, it is very important that we start recruiting members and showing them the basics of the program. By bringing in new members, we will be able to insure that the FTC program at CCHS will continue to thrive. To do this, we will be showing off our robot at a school assembly, and possibly going to the middle and elementary schools as well. We still have some work to do before the robot is ready, and we are planning on making some special adjustments to the robot to make it faster. Now that we aren't limited by the game rules, we can modify our robot in any way to make it do what we want for the demonstration. Tyler has also been working on replacing all of the gears in our gear box with sprockets and chains, in order to make the scissor lift more reliable.
Leading up to our final competition, Tyler and I made a few small changes to the robot in an attempt to keep our gearbox from failing during the competition. We also spent several hours practicing in the arena we have set up in our room. Saturday morning around 6:00 we packed up the robot and left for Humboldt. When we got there, we submitted our engineering notebook and signed in. We had plenty of time before the games began to make sure everything was perfect with our robot. We were scheduled to compete in 7 matches throughout the day, and our first three went very well. However, we began to have some mechanical problems halfway through. Unfortunately, by the end of the day our gearbox was almost completely shredded, and we ended up close to last place. At the awards ceremony, we won a trophy for our creative scissor lift design.
To fix the issues we had in the gearbox at the first few competitions we considered using sprockets and chains to run the entire gearbox, but we realized that we would have to make the gearbox much larger to achieve the same gear ratio, so we threw this out. We ended up keeping the same design for the gearbox, with a few minor changes to eliminate potential problems. Another major mechanical failure that happened was the final gear slipping. Because the 5/16" axle did not have collars on it to keep the gears in the correct place, the gear went to the side after torque was applied over time. We were not able to fix this problem during that competition, because the gear was completely destroyed, but we were able to replace the gear and make a collar to fit the axle to keep the gears in place. Since applying this collar we have not destroyed these gears, so it seems to be working, but we made the collar the wrong size, so tape is placed on top of the axle to make the collar clamp correctly.
The schedule for competitions has been packed ever since they began. Every saturday we have had a competition, and the last one is this saturday. The odds are against us, but we could potentially advance from there. At the recent competitions we have had several mechanical errors, mixed with electrical issues, some of which were unavoidable. The first major mechanical failure we encountered was due to the relatively weak axles used in the gearbox of the scissor lift. The pulling force the chain put on one of the 3/16" axles was more than enough to bend it towards the 1/2" axle, which was much too strong to bend. This axle was bent to the point that the chain began to slip on the sprockets. We fixed this problem after the first competition by replacing the 3/16" axle with a 5/16 axle, which would fit in the channels without bushings, eliminating play and increasing strength. We would soon find out that the next axle in line had also suffered damage from the immense torque required to lift the scissor lift with a 54:1 gear ratio. Fortunately this issue has not caused any major failures, yet. Today we will likely replace this axle with a 5/16 as well, to prevent future damage.