GEMS OF WISDOM
- Even if you've done a proof-of-concept on something, never underestimate the time it will still take to bring it to fruition. There will always be some complication or new requirement that you hadn't thought about.
- GrabCAD is your best friend.
- You only have one bot, and not everyone can work on it at the same time. Plan your schedules accordingly.
- Having a "works-like" prototype early in the game is huge. It is much easier to get away with scrapping the aesthetics than it is the functionality.
- printf statements take a long time and will mess up all of your communication.
- Consider voltage regulators with 7-segment displays for both the input and output, like these. They will save a lot of battery-level debugging time.
- Be prepared to use the Pro compiler for the PIC, especially if you are nearing your program data limit.
- The sooner communication is working, the sooner you can integrate and actually see the rewarding results of communication.
- Don't try to use a single drive fan. The groups that did this had trouble turning in tight spaces. Having two fans makes it possible to turn in place and makes navigating the crowded playing field much easier.
- The closer to the center of the bot your fans are, the easier it is to make tighter turns. If you put your fans at the back of your hovercraft, you won't be able to turn around in small spaces.
- Spend time getting familiar with controlling your bot. For example, knowing that your bot will rotate another 15 degrees after you stop turning (or creating a control loop that avoids that) is really important for the grading session and game day. Even driving it around for 20 minutes will improve your command tremendously.
- Spend a lot of time at the beginning prototyping skirts. Make one, test it, make another, test it, and repeat until you are comfortable making it and you have determined what works best for your geometry. This way, you can pound out another very quickly if you ever need to iterate again.
- Flexible skirts work best, but a drawstring on the skirt only works for circular geometries. Sandwiching the bottom of the skirt between thin sheets of Duron allows for a great deal of flexibility even over some rough surfaces but allows the skirt to balloon out evenly in all directions for non-circular chassis geometries. Also, it makes skirt construction easier, in our opinion.
- Ripstop Nylon from Joanne Fabrics is the class favorite for making the skirt.
- Learn to set up and use the Room 36 sewing machine so you can make a robust skirt. Don't rely on tape and glue more than you have to - it really makes the skirt unstable!
- Having a smooth skirt bottom can be both an advantage and a disadvantage. The decreased friction makes your hovercraft much faster but harder to control.
- Going in reverse and being able to brake will make your navigation SO much easier.