I’d also be interested to know what the reasoning is behind having three wheels on the goalie and four wheels on the offensive robot in spite of the weight penalty associated with that.
Also as a ref: Don’t forget to add handles to your bots, esp. with regard to the weight budget, handles are allowed extra height but not extra weight.
After researching past team’s robots, we saw a major issue with some of the designs, specifically the replacement of batteries. To combat this issue, we decided to use velcro strips attached on the robot and the battery packs so that the batteries can be easily removed from the robot. Additionally, we also kept in mind that the battery packs may fall out while the robot is moving around the field, thus we added small walls holding the battery packs in place, as can be seen in both Chassis designs.
The power regulator on the Leonardo wasn’t able to handle up to 500 mA, thus we used a L7805 1.2 Amp Voltage regulator and attached a TO-220 Clip-On Heatsink (found on Adafruit) with thermal paste to cool the regulator. With the assistance of the external regulator, the Leonardo was able to handle the amount of amps required for the different sensors and motors.
The weights on the spreadsheet for our poster was estimated to be the worst case scenario, mainly for our plates since at the time of making the spreadsheet we hadn’t completed our designs. When we actually printed our plates, they were much lighter than we projected them to be, especially with all of the holes we put into our plate to save weight. This made up for the overweight of the offensive robot on the spreadsheet. The spreadsheet contains inaccurate data, as we only used 20D motors. We have changed this in our poster.
We decided on using three wheels for the defensive robot because the robot didn’t require as much speed as the offensive robot and the loss of one motor compensates for the weight from the kicker and dribbler on the robot. On the other hand, the offensive robot relies on the momentum it generates to propel the ball, thus adding a fourth motor would allow for a higher maximum velocity. Thanks for your question, David.
