End of Week 1 / Beginning of Week 2
Choosing a Robot Architecture
Our team’s big goal by the end of week one was to have a locked-in decision on our robot architecture, so that’s what most of our late-week-one activity was focused on.
Even though our amp testing showed that we could likely shoot notes into the amp from below fairly consistently, we still ended up deciding that we wanted to score into the amp from above. Like we said in the amp testing update, we believe scoring into the amp from above will be quiker and less sensitive to robot alignment.
Our 3 main ronbot architecture options reflected this:
Option 1
Slapdown intake that hands off to a pivoting shooter
The idea was loosely inspired by this early-season CAD. We liked that this architecture featured mostly mechanisms we were familiar with, but weren’t as happy about the idea of two servoed degrees of freedom interacting for a handoff.
Option 2
Tall, single stage elevator with a pivoting intake that passes through to a shooter
This was the only one of our 3 options that could score in the trap, and definitely the most complex. The climber is integrated into the elevator, with passive hooks at the bottom of the base stage and a set of hooks on the carriage, which saves a little complexity, but we still felt like this architecture would push our team’s limits, especially on the programming side for the elevator’s passthrough logic. We also didn’t feel 100% confident that this architecture would actually score in the trap, despite looking like it, as there are a lot of chain interactions that might not go as expected.
Option 3:
Under-the-bumper intake feeds to a large, pivoting shooter
This option is sort of a combination of team 95’s intake and the Unqualified Quokkas Ri3D. The under the bumper-intake felt unfamiliar, but we really liked how simple and robust it seemed, while still allowing us to have a full-width intake. This architecture does require a large mass to pivot to score in the amp, but we think that there’s plenty of room for ballast if it comes down to it.
Decision
After a team discussion on friday, we decided on option 3, which means we aren’t going to score in the trap. We think that by going for a less complex robot, we will be able to make a more polished robot that scores more points at the end of the day. We are aware that this will likely make it difficult to rank highly at our events, but still feel that the tradeoff is worthwhile.
Prototyping
We’ve been snowed in for the past four days (and maybe more to come), so we haven’t done a ton of prototyping, but we were able to get in one test to verify the geometry of our 95-style intake.
The intaking looked good, but the note got stuck against the ground when we tried to eject it. We unfortunately didn’t get video of this, and didn’t test further out of fear of damaging our only note, but we hope to run more tests once we get more notes. Our current guess is that moving backwards while ejecting will fix the issue.
CAD Progress
The CAD isn’t entirely done, so I won’t be going into too much detail on each subsystem yet, but here are the links to our CAD documents, along with some pictures:
Main
Drivetrain & Intake
Pivot Structure
Shooter
A couple of things to note on our designs so far:
- We haven’t done any design for our climber yet, but the current plan is to use one telescoping climber on either side of the robot for a basic chain climb that can reach the high parts of the chain
- The power transmission for the 95-style intake ends up being somewhat complicated (but not too bad). We’re currently using 4 timing belts and 2 polycord reversals.
- We opted to build our shooter out of HDPE. We wanted higher rigidity than polycarbonate, without the weight of aluminum, and enough thickness to counterbore mounting holes. As a bonus, notes slide well on HDPE, so we don’t expect to need to line our shooter with any other material.
