Weeks 2-5
Boy have we been busy! We are fighting hard to stay on track for our week one competition, and working on getting a comp-ready robot by the end of next weekend. Until then though, let’s look at what has happened over the past couple of weeks.
Manufacturing
Bumpers
This year, we decided to make our bumpers before week 8! We are using a uni-bumper for the first time, and had some difficulties while sizing the bumpers, but are at the point where all that’s left to do is finally mount the angle brackets to the bumpers and they should be good!
Chassis
By around the end of weekend 4, we finally finished our chassis! We are going with a 30” x 30” frame with the SDS MK4i modules in the corners, and had a nice fancy belly pan laser cut and spray painted. Once we got through the troubles with running wires and avoiding other components, the swerve was up and running!
We also got our 3D-printed swerve covers mounted. They simply clip onto the vertical spacers of the swerve units and were inspired by the clever design of Ajax Bachor. However, our design fully encloses the gearing of the MK4i units. Further, the covers accommodate 40mm muffin fans with snap-on filters to slightly pressurize the swerve units with clean air to keep carpet debris and other junk out. We have shared step files for the covers on GrabCAD here.
Intake
We used our routers to cut the side plates for our intake, and ran into some issues with not having the rollers close enough together to compress the game piece. Fortunately, it was easy to cut another piece with slight modifications and the intake has been tested on the robot. It finally works!
Shooter/Integration
Our shooter manufacturing came along pretty smoothly. We had some minor struggles with the pre-drilled extrusion from West Coast products. A number of the machined holes were slightly misplaced compared to the rest (not evenly spaced on 0.5” centers), so we had to drill out our polycarbonate holes slightly to align with the extrusion holes. We confirmed with both caliper measurements and other pieces of extrusion that the piece we had prepared for the shooter had the misplaced holes. We also had some issues with ordering the correct belts as well - oops. However, we found some work-arounds and the shooter has now been mounted. The initial transfer of notes from the intake to the shooter was not as smooth as we would like, so we are working to fine tune this. Our detailed CAD work this season has really helped minimize integration and configuration challenges prior to robot build.
Climber
We assembled our ThriftyBot telescoping tubes around weekend 2, and they came together pretty easily! We have also routed hooks to go on both of them out of ¼ inch polycarb. The hooks were designed with inspiration from 4481’s chain-catching design. Now, we are working on mounting the transmissions to the underside of the bellypan to drive the winches for the tubes. That should be the last step for the manufacturing of the robot!
Software
Auto
Before taking it apart for components, our swerve test base managed to follow some PathPlanner paths rather precisely! Now that we have the robot, we’ve been testing our auto system and it works well. We have an issue with path-following precision, so we aren’t able to pick up more than two notes precisely before the robot drifts off of the path, but hopefully we will be able to correct this with vision.
Vision
We briefly tested Photonvision’s pose estimator as well as Limelight’s pose estimator. We are hoping to go with Limelight’s software as we just picked up a Limelight 3, but we aren’t committed. Either way, it should prove very helpful with odometry.
2024 Robot
We have outlined all of our subsystems and tested our intake code. It works great, which is nice. Next weekend, we will be tuning our shooter setpoints - speeds and angles - for the speaker, amp, and hopefully trap. We will also be testing code for our climbers and building more autos. Our goal for Hartford - week one - is to have two shooter setpoints - from the subwoofer and from the protected zone on the stage - as well as to be able to shoot into the amp and theoretically the trap as well. From there, we will turn it over to drivers and keep building autos!
Oh, and one last electronics mishap…
We had a network switch short and it took out the vrm that was powering it as well as the Ethernet port on our Rio 2.0. We can connect to the Rio via usb and it works as expected. However, we get no comms when connecting via Ethernet. When a laptop is plugged into the rio’s Ethernet port, the Ethernet status lights will light up and stay on until the rio is power cycled, even if Ethernet is unplugged. Connecting the rio to the radio shows no status lights on the rio’s Ethernet port light. We didn’t see any visible damage to the rio when opening it. Figuring this out took a while as we were replacing everything on the networking stack trying to find the source of the comms failure. We replaced Ethernet cables. Tried connecting with different computers. Replaced our radio power module. Tried a new radio. We finally pulled the rio and replaced it with a spare and our issue was resolved. We are fortunate to have had a backup rio on our motor test board and have swapped the two, as we usually use usb to connect to the test board anyways. The only downside is that we are no longer working with a Rio 2.0, and hopefully we will not see any performance struggles as a result.
Design and drive team will be posting updates soon! I will also make a post ideally tomorrow with relevant media, like auto path tests.
Written by @kr1699 (me), Abby (senior captain), and @seth-crampton