Week 2 has come to a close. Unfortunately the school board decided to cancel our Saturday build day due to the inclement weather so we only had 2 short build days this week. The team definitely made the most of them. Students were busy constructing and testing prototypes, specifically for the intake and indexer. This year our team has been using the ‘protopipe’ system that team 3847 designed for rapid prototyping. It allows for the use of ½” PVC pipe rather than wood or aluminum. It definitely saves time and resources. Special shout out to 3847 as well as the Burlington Public Library Alton branch for their 3D printer!
Here is an example of it in use:
The intake team was hard at work using the protopipe to mock up an intake. Their goal was to center the ball prior to it entering the robot. They tried a couple different types of intake wheels that use angled rollers to move an object sideways. They also needed to try different speeds, compression on the ball, and distance between the wheels and the robot bumper. After many iterations, they found success! They did note however, that if a ball was coming from each side of the intake, there would be a jam in the middle. They also weren’t sure if it would be possible to move a ball laterally while driving the robot forward. Next they are going to try to find a way to bring multiple balls into the robot at once over the bumper as quickly as possible while driving forward.
We have decided to use the same style of chassis that we built last year. However, we have decided to go with off the shelf gearboxes to accompany our new Falcon 500 motors. With so many other moving pieces to this robot (no pun intended) we thought designing and fabricating gearboxes for these new untested motors was too risky. Next we have to determine the dimensions of the drivebase.
The shooter team sketched up and cut side plates on the CNC for the shooter prototype. They also fabricated some ½” hex hubs out of Delrin for the main shooter flywheels. They were planning on shooting power cells on Saturday but will have to wait until our next build day on Wednesday. There are a lot of variables to consider when shooting these balls which include: Compression of ball, RPM of flywheel, hood material, and hood angle just to name a few. We’ll post some pictures and videos next week.
We are creating a small indexing prototype to see how the ball reacts to getting moved by timing belts. We are hoping to use this method to elevate the ball up to the shooter. During week 3, we plan on prototyping a mechanism which will serialize the balls from 5 balls to one at a time so that they can enter the mechanism previously mentioned. Photos and videos to follow.
The climbing team has been busy running calculations, sizing motors and gearing them properly in order to lift the robot off the ground quickly. They also have to consider how the robot will not fall back down when power is removed (game requirement). The packaging of the climbing mechanism on the robot will likely have to wait until some of these other subsystems have been somewhat finalized.
The team in charge of spinning the control panel has been busy building the control panel itself as well as determining which motor and wheel they should use to spin it (to win it)!
Next week’s goals are to test another intake and mount it to last year’s robot so that we can start driver trials, have a working and dialled in shooter, choose an indexing and serializing method, and begin building our drive base.