The Zebracorns - Behind the Stripes - Design, Code, and Build Blog (2023/2024)

[marshall]

This post has been a long time coming. Some folks probably know who we are and what we are all about but others might not so let me introduce any newcomers to The Zebracorns.

The Zebracorns (Team 900) started competing in FRC in 2002 (technically the name was “Team Infinity” back then). The team was started as a partnership between mentors and students at the North Carolina School of Science and Mathematics with the goal of introducing students to engineering principles through practical application. The team has since opened up membership eligibility to include students from the local community. Durham Public School students, other local public school students, private school students, and home school students are encouraged to join the team. The team now openly recruits students from all over the triangle area and routinely has over 50 student members (we don’t yet know what that count will be for the year).

The mission of The Zebracorns, a FIRST® Robotics Competition team, is to inspire and empower students across North Carolina to be exceptional innovators and leaders. Our students and adult mentors work together to learn and apply real-life multi-disciplinary skills, fundamental engineering techniques, and cutting-edge technologies through a creative design process within a culture of personal and team excellence.

Our Zebracorn mascot, though a bit fanciful, has a significant meaning. Our team was founded in a boarding school in Durham, The North Carolina School of Science and Mathematics, whose mascot is a unicorn; however, our team is made of students from various schools around the area and home-school students. To represent this diversity, we added stripes to the original unicorn mascot and created the Zebracorn (upon the chance of some re-branding).

We work out of our space in the Mechantronics Lab at the North Carolina School of Science and Mathematics. The lab is in the Hunt dorm (it’s a residential high school - some of our students live on campus!) and we share the space with robotics classes, programming classes, occaisionally the rocketry team, FLL teams, and FTC teams.

Our biggest sponsor (don’t worry, other sponsors will get their own posts later, we know some of you are watching), by far, is the NCSSM Foundation, an entity founded in 1979 to support the mission of NCSSM. The North Carolina School of Science and Mathematics Foundation has been organized to operate exclusively for charitable and educational purposes, including, but not limited to, receiving, administering and granting funds for the support of the academic and educational programs of, and any other phase of operation or program of, the North Carolina School of Science and Mathematics, as the Board of Directors of the NCSSM Foundation in its discretion may deem appropriate for the advancement of education. We can’t thank these folks enough for literally everything they do to enable and support us. It’s a tremendous amount of work and we’re humbled by it.

Ohh and we like to use ROS… and talk about it. We’re also big fans of neural networks and doing interesting things with them. Feel free to ask us questions about it! There will definitely be more posts about it as we work our way through the coming season.

• So what’s up with this post then?

Well… in true Zebracorn fashion, we are experimenting with what it means to have an open build process for the 2024 season (and possibly beyond). We already go above and beyond with sharing a ton of information with everyone, including teams all over North Carolina and all over the world so we are embarking on this effort as an extension of that work.

• Does this mean The Zebracorns will be an Open Alliance team?

We don’t know yet but we are hopeful we will be considered and plan on applying. Even if we aren’t considered one, we are going to document quite a bit here over the coming season, including opening our designs, our ideas, and our code.

• So what do The Zebracorns have to share today?

Ohh do we have some truly cool stuff for you today. We’ve got a long overdue revision to our very popular battery whitepaper (ZebraPower 2.0 - The Zebracorns's Battery Paper Update). We also have an update to our ZebraSwitch paper (Zebraswitch 2.0 - The Zebracorns upgraded Ethernet switch paper). They have their own threads but we’re happy to answer questions about them here too and felt like the combination of the two would be a pretty great way to kick this off.

We also released a paper from design and research work that one of our recently graduated seniors worked on this past year as part of the first ever cohort of the EE4300 Topics In Engineering - Robotics Design class at NCSSM: 2023 Intake Design Report

That’s all for now but you can expect more from us very soon. We are hopeful we can do about one post every couple weeks in the pre-season and average about one per week in build season. We’ve got a lot to share this coming year and we’re excited to share it with all of you. If you have questions then feel free to ask below.

Most of the posts here will likely be coming from Marshall (yeah we know, but he’s already on CD so it’s easier on us to get him to post) but the work going into those posts is coming from a lot of mentors and students and they’ll likely be posting and answering questions too so you can probably expect to see some new characters from time to time. While many of the posts might say “marshall” is the author, please note there is an army of people in striped pants writing things and contributing!

[Jimmyy]

Gotta love NC teams for being open! Excited to see what yall put out here!

[David_IsMe]

I’m very excited to not only see the progress but to get information on the why’s behind design choices! Gotta love NC teams for being mostly transparent.

[Katie_UPS]

I really like the intake design report and plan to share it in my engineering classes as an example. It hits all the documentation points that I want my students to demonstrate and its something half of them are already interested in

[marshall]

Ok, it’s been a while. We’ve been busy - but in a good way. Our pre-season has so far seen over 60 students join The Zebracorns for the 2024 season. Which is awesome but it’s keeping us very busy!

What’s a normal pre-season meeting like?

For us, we meet twice a week and broadly divide the team into two areas “mechanical design” and “programming”. That doesn’t mean that is all we do but we ask that all students choose one of those areas to focus on and learn about to help keep them grounded to the robot and the competition, no matter what they are working on. One meeting each week is a required curiculuum meeting and the other is a non-required but highly suggested project meeting. We alternate which sub-group has the required meeting so we can keep things reasonably divided but still have everyone meeting.

We’re very fortunate in that the school doesn’t just provide us with a classroom that we work out of but we’re also able to book other classrooms on campus and expand into them as we need quieter areas for more classroom based work. We’ve found this can help some folks focus a bit better than in our lab so we will hold curriculum lessons there!

The curiculuum meetings are where we teach the basics - things like OnShape and Python. Our aim is to get students familiar enough with some subset of tools/skills that they are willing to spend time outside of the lab on their own doing their own experiments.

The project meetings are more hands-on learning. Things like tool use… locations of parts. Taking old robots or game elements apart. Organizing and prep for the season. Lots of stuff. We also talk about ongoing projects and work on them, bringing new students along for the ride and helping them find their passions.

We finish every meeting with a really big human circle where we go around and have each person (mentors too!) say their name, their preferred pronouns if they’d like to share them, and something they learned that day. Sometimes, that can be something completely unrelated to robotics and it can be quite funny - other times it is something from the lessons and projects of the day. This process can be slow with 60+ people in the room but we’ve found it is one of the best ways to get to know each other and help build our team.

After the meetings are over, our leadership students (and others) will post a summary of events into the “Meeting Summary” channel in our Mattermost. We’ve found this helps us keep up with what happened and keep anyone who missed it informed:

What else have The Zebracorns been up to?

We took some time last weekend to compete at the Doyenne Inspiration East event. The Doyenne events are off seasons hosted by FIRST North Carolina and keep the pits and drive team roles restricted to female and non-binary participants (both mentors and students). The male members that went, were in the stands cheering and bringing the team spirit!

While we recognize that FRC is a sport for all genders, these under-represented groups deserve a day in the spotlight. We had a group of 3 female leadership students over the summer propose that we go and it was agreed, provided they helped recruit more young women to participate on the team in the fall. Not only did they hold up their end of the bargain but they’ve given us one of the highest percentages of female members that we’ve had since pre-2020. That’s a huge win for us and our team’s diversity goals!

At the Doyenne East event, after ranking 4th place, we captained the Winning Alliance (Alliance number 3) with our our first pick, the Eastbots (4795) and our second pick, The Chargers (5160). Huge thank you to both of those teams! And a huge thank you to all of the teams there and especially the Jag-Wires (7443) for hosting it!

We did learn one REALLY important lesson from the Doyenne East event that we want to share with everyone - teams… educate your drive teams (no matter how new or old) about the E-Stop button at the events. It’s the big red button in the driver station.

At some point, things in our driver station got swapped around and that resulted in our robot hauling itself at 2.5m/s across the field into the opponent’s community where it proceeded to fuse it’s wheels into the carpet (seriously). We had explained the E-Stop procedures in the lab to our new drive team members but… as it turns out… they are different at a competition. So, lesson learned. Big red button. Smack it if you need to or unplug the Driver Station from the Ethernet connection. We’ve also told our Friendly Neighborhood FTA (Hi David!) that they should have FIRST add something about the E-Stop to the drivers meeting script since teams can’t practice with it at home).

Pics of the damage (no, we really are not proud of this but we wanted others to know what can happen - even when you have a current and velocity limited robot with colson wheels):

Shockingly, after getting it back to the pits, all we had to do was scrape the major crude off the wheels and it went on to drive just fine for the rest of the event. Colson Collective FTW!

Anything else to share?

Our programming team has been hard at work! We’ve been working with NVIDIA and, thanks to a generous donation from them, we are getting ready to put an Orin AGX onto the 2023 season robot for testing. It was an extremely generous gift from our partners over there. We’re eager to do some testing with it and see what we can do with it beyond our existing vision pipelines. It might seem silly to some to put a piece of tech on a robot that is illegal under the current rules because of the cost limits but one of our goals is to put tech like this into the hands of our students and prepare them for what they’ll be working with when they hit college and beyond. We look at it like any expensive tool - the more exposure and experience we can provide, the better outcome for the students in the long term - teams aren’t putting Haas mills on their robots but that exposure and experience to machining is useful - same is true of machine vision and ML technologies.

Speaking of… our next ZebROS paper is coming very soon. It’s been in the works for a while and the students and mentors are putting the final touches on it… maybe one more week? We hope.

Stay tuned. More to come.

As a PSA: We highly recommend everyone get their COVID boosters and Flu shots as soon as they can! A lot of our members come down with illnesses this time of the year and we want them to stay as healthy as possible so they can be positive contributing team members. So get your shots if you can! It’s worth it for your teams! We won’t use it as the reason this post is so late but it was definitely a contributing factor! Go get your jabs!