FRC 2881 The Lady Cans - 2024 Open Alliance Build Thread

[LadyCans-FRC2881]

Hello and welcome to the 2024 build thread of FRC Team 2881, The Lady Cans! We are honored to be participating in openalliance again, and to share our ideas with the FRC community for the second time! Our team was founded in 2009, and we currently have around 40 team members on our team. We will post photos, software, and CAD screenshots weekly, along with any videos of the prototyping and testing process throughout the build season. Our team will be competing at FIT District events in Waco (week 1) and San Antonio (week 3). We’re all super excited for Crescendo in 2024!

2023 Season Recap

At Waco we earned our first Winning Blue Banner in 15 years of being an FRC team, as well as earning the Creativity Award for our 2023 robot, SCoRpion! At San Antonio, we were ranked 6th, and were awarded the FIRST Impact Award. At the FIT District Championship, we competed on the Mercury Field, and earned the Creativity Award. We ranked 23rd in the FIT district, earned a spot at the World Championships, played on the Galileo Field, and earned the Imagery Award!

During the off-season, we traveled to TRI, The Remix, and STEM Gals/NTX to compete with our 2023 competition robot, SCoRpion. We used this opportunity to train a new drive team, and introduce our many new team members to the competition experience!

[Larry624]

Lady Cans were awesome in 2023. Looking forward to 2024.

[moore_ryan]

So excited to see this thread! 8088 had lots of fun playing with your team at Waco last year. Good luck in 2024!

[LadyCans-FRC2881]

Kickoff Weekend Recap

Following the reveal of the game animation on Saturday, our team immediately went through the new game rules, to start thinking about possible ideas for our robot this year. The first thing that we noticed was that our bumpers must go all the way around the robot, and that the extension limit is more restrictive than usual. This was the main influence on the possible design ideas that the team came up with.

After mostly brainstorming and planning on Saturday, we had a general idea of what we are going to build. The first design decision was based on our experiment with an internal intake idea. With an internal intake, we wouldn’t need to extend outward to pick up notes from the ground, and could instead pick them up from under the robot. We also plan to create an arm to guide notes toward us from outside the frame, to make any autonomous pathways we include much more efficient. While we don’t have a specific material for these rollers yet, prototyping things in the coming week will help us narrow this down.

For the actual scoring of the notes themselves, we plan to design a shooter on a pivot, so we can score from multiple locations. The current plan is to adjust the angle with a lead screw (or two), as we have used them in the past. It will include multiple rollers on the top and bottom to give even compression, and allow the note to fly flat through the air. We did prototyping for this idea on Sunday, and found that it works consistently.

We are currently experimenting with the speed and angle of the shooter to see how it affects the flight path and angle of the note, and adjusting our strategy according to what seems to work the best. Since it appears we can change the angle that the note flies, we might be able to score in the amp with the shooter as well. We can do this by having the top roller spin slightly slower, resulting in the note eventually turning vertical. Videos will be added tomorrow.

While the climbing mechanism is still being developed, we are also going to incorporate lead screws into the design. They have worked well for us the past two years, and will allow the climber to stay in place when hanging. We plan for this climbing mechanism to have a part attached that will act as the scoring mechanism for a note to go in the trap, so we can get points toward the Ensemble RP during endgame. How this part will look/function is under consideration, and will probably be developed alongside the climber later on.

The programming team has also been hard at work preparing for all of the different subsystems that we could have on the robot, and outlining everything accordingly. These are going based on what we will likely have, but some changes might be made along the way.

[LadyCans-FRC2881]

Here is a link to our testing videos for the prototype scoring mechanism that we plan to use this season. We were experimenting with the speed of each roller to see how it affected the flight of the note, and these were a collection of the most promising results.

We were also able to switch the drive motors on our swerve drive base, so programmers can temporarily use the new NEO Vortex motors that we have.

[AllenGregoryIV]

awesome test video, what diameter wheels are you running on that test setup?

[LadyCans-FRC2881]

2.5" Vex Colsons. Each set of rollers is direct driven by a Vortex so we can easily adjust wheel speeds for testing. The gap between the rollers is about 1.25" in those videos, we’ll update if that changes.

[LadyCans-FRC2881]

2024 Robot

The robot is currently going to be a 25inch cube without bumpers, and the climber will be the tallest thing on the robot. We are planning to have our main intake be fully contained under the robot. While the possibility of it being able to pick up from all sides was up for consideration, we have decided to stick to only being able to pick up the notes from the assigned front or the back of the robot. After prototyping this idea, we didn’t think it worked well enough for the benefits it could provide. Plus, swerve drive allows the robot to turn very quickly, so we will still be able to pick up notes from the floor just as well. We added these testing videos to this photo album (same link as before).

We are also going to include a guide intake that will reach over the bumpers to guide any floor notes that we can’t drive over closer towards us. This will allow the robot to have more reach for our possible autonomous pathways as well, so we can grab and score the notes much quicker. It will be built with rollers that will quickly draw the note toward the internal intake, by very slightly compressing it against the ground. We noticed that the note slides easily across the field carpet, so there shouldn’t be any issues when picking them up.

Due to the dimensions of the note, the intake will take up most of the room lower to the ground on the robot, and so the scoring mechanism will have to connect directly to it. We plan to have one side directly connected to the launcher (likely the designated “front” of the robot), and the other will follow a channel to get to the direct pathway (hopefully without bending the note a ton).

Here’s the current design for our scoring mechanism. We were originally going to use a series of rollers to speed the note up, but through testing we determined that this wasn’t actually necessary. So, now the robot will have two rollers to score the note into the speaker. We are using the 3in ION Grip Wheels by REV Robotics.

Here’s the plate that we are going to mount the intake rollers to, and the intended pathways that the note will take from the ground to the scoring mechanism.

CAD

The CAD team has finally assembled to begin making the full robot in solidworks, so that we can machine the parts that we will need. We have started with the drive base, will focus on the intake and guide next, and then finally the shooter and climber. The team always designs the robot in CAD before making anything of importance. We do this to check the weight, spacing, and dimensions before possibly wasting the material that we have available. Additionally, since we do everything in stages, we are able to add vinyl to each part after it’s manufactured and before it’s added to the robot (because who doesn’t like a fully pink robot).

Programming

The programming team now has a swerve drive base to plan autos with, and they’ve been experimenting with path planner to get to and pick up the notes that we plan to score in auto.

Bumpers

Due to the rules about having bumpers all the way around the robot, we’ve designed a new bumper mounting system for the corners of our robot, so it will take up less space than last year. This will allow us to have one bumper (goes all the way around) in each color, so we can make the switch much easier, and assure that the bumpers will stay on/not move when driving on the field.

[LadyCans-FRC2881]

CAD

We’ve finally finished the majority of the CAD for our 2024 robot, with only a few more additions to follow. The things still on the list to 3D print are spacers for the intake pulleys, and the motor mounts for this year.

Manufacturing

Production of the sheet metal and Lexan parts have begun, and will hopefully be finished in the next week. We’ve already done the two supporting side plates for the internal intake, and part of our battery container. It’s going to bolt straight onto the frame, as low as we can put it.

Build

After putting vinyl onto the side plates, cutting the hex shafts, and creating the belts, the build team assembled all of the parts that we have for the internal intake mechanism. We’ve added everything onto temporary frame rails, since the ones for this season haven’t been made yet. This way we can test everything before it goes on the robot, and programmers can begin to think about how to run it. We’re going to run the intake with three motors. One motor will be used for the intake rollers, and the other two will be used to move the note with belts. We are also going to have two motors for our guide intake-one for the rollers, and one for the pivot.

Programming

Programmers have been planning autonomous pathways with the swerve base that we have, successfully managing to run a couple. They’re able to do this since our robot only has to drive over the notes to pick them up. When we have the full robot assembled, they will incorporate the guide intake into these paths. The plan is to strafe sideways over the notes in a line, and score as we move. We have designed wheel guards to go over our swerve modules, to prevent us from driving over and getting stuck on any notes.

Field

We’ve been working with taped lines based on the CAD available to teams. Additionally, members of the team have now created a combined speaker and amp for testing, as it takes up less space.

[LadyCans-FRC2881]

Fast Facts about our 2024 robot:

• Our robot’s frame perimeter is 25” by 28”
• It will be 27 ½’’ tall, so we can travel under the stage
• Our drivetrain for this year is swerve (given that the field is flat), and is geared for 18 ft/s.
• Our under-the-bumper intake can pick up from the front or the back of the robot
• The feeder intake is the designated “front” of the robot (for programming reasons), and it’s there to give us extra reach to pick up notes in autonomous
• We are adjusting the launcher’s angle with a lead screw so we can better hold its position for scoring
• The climber is also designed to score in the trap (on the chain that we climb), and we’ll pick up this note from the source (as it doesn’t connect to the internal intake)

CAD

Here’s the CAD team’s final robot! According to Solidworks, the center of gravity is 3 inches below last year’s, at 6.5 inches above the ground!

After testing our arm, and figuring out that it wasn’t as rigid as we’d thought, we designed a piece to add additional support (shown in the photo below). This worked incredibly well, and the arm is way less flexible than before.

We’ve also modified our battery location for this year, so it can sit as low as possible to keep the center of gravity as low as we can. It’s also opposite the climber to keep the center of gravity in the middle of the robot.

Machining

Part of our build team has been manufacturing parts constantly for the last two weeks, and we’re almost done. The only thing left to add to the robot is the climber and that should be done by the end of this weekend.

During the prototyping phase, we experimented with different kinds of hooks for the climber arm, to test how well they worked to hold the robot on the chain.

Build

Most of the robot has been assembled, and we’ve finished the majority of the wiring. We’ll need to adjust things slightly when we add the climber, but it’s all neat and organized for now. All of this is covered by a second layer of electronics and a cover panel to protect it, but here’s what we started with.

Our reasoning for choosing to make a multi-directional intake was to minimize the number of times we would need to turn around during a match. Since we can pick up from both sides, we can keep the launcher pointed toward the speaker to score as soon as we are lined up.

Programming

Programming has been working on creating the subsystems for the robot, and they have been named feeder (intake), intake (internal), launcher (for the notes), and arm (climber for endgame).

Now that we are done wiring the robot, the programmers have gotten an actual robot to work with. We took apart the practice chassis that they were using previously, so they were working on our lighting system for this year. We use lights for driver feedback, and just because they look cool.

Our first attempt at driving the 2024 robot is here (scroll to the bottom, it’s the same album I’d linked before in this thread).

Kit Bot

Some of the newer members of our team have been working on building a kit bot for our alternate drive team to practice with (when the competition drive team is using the competition robot). We have decided to do this to keep people busy while the programming team has the robot, and give them the chance to continue to refine their skills during the build season.

[LadyCans-FRC2881]

Build

The electrical team has finished wiring our robot, and there have only been a couple issues so far. Due to how compact we made the robot this year, there’s little leftover room for electronics and the wires that connect everything. We have room for most of the electronics in a box under the feeder intake, but everything else had to be added outside and connected to the inside. Once we added the climber to the robot, we had to redo everything to make sure the hook wouldn’t catch on anything important, and that nothing was going to get cut by the launcher (as it moves up and down). However, now that we have been able to give the robot to programming, they’ve been able to make everything work as it should, and none of the wires have been in the way of anything important.

To support the climber when we use it, we’ve also added a cross-bar from the battery side of the robot to the climber/trap mechanism. Some slight alterations had to be made when assembling.

We’ve also created our bumpers for this year. We make a total of three bumpers for each competition robot that we have. One blue and one red (competition legal) for matches, and a black set with pink letters for sitting in the pit/the demos that we do.

Also during testing, we noticed a few things that need to be changed. First, when the note travels into the robot from the ground, the belts that we are using were staggered, and that was causing gaps to show up. On a roller that was more internal, we had spacers less than the diameter of the rollers they were next to, and that was causing the note to get stuck. So, we’ve added rollers (without a belt) onto those dead spaces, to prevent the note from getting trapped.

We’ve also noticed that when the note travels to the launcher, the panels that are being used to guide it on the top and bottom aren’t working, and the note gets trapped right outside of them. So, we are going to remake these panels to have a bend on the end to act as a funnel, so this problem will stop occurring.

Programming

The programming team has spent time testing our locating abilities with the many April Tags on the field, as well as experimenting with the camera placement on the robot. Our plan is to add two cameras for April Tag detection, and one for driver feedback/note location. The two cameras that we were experimenting with for April Tag detection have been temporarily added to the climber for height and angle testing, and a permanent mount for them will be added later on. One faces to the side of the robot, and one faces to the back of the robot (direction of the launcher). This will allow us to see at least one April Tag at all times, so our robot will eventually be able to score on its own. This is more beneficial for auto, but will be very useful in teleop as well.

[LadyCans-FRC2881]

Build

During testing, we found out that the weight of the robot acts differently on the chain than we initially thought, so we are too short to score in the trap. We’ve quickly redesigned the top of the climber to fix this issue. It works perfectly though, so it should work no matter what.

The robot’s low center of gravity allows it to stand on the side, so we aren’t able to tip over. The belts on the bottom are around ¼” off of the ground.

Electrical

Much of the past week has been spent figuring out a replacement for the distance sensors. We were originally using it in our intake and launcher. It appears that we were experiencing enough static electricity between the note and the belts on our intake, that was causing the time-of-flight sensors on the I2C bus connected to a raspberry pi coprocessor to be disabled and temporarily disappear. We could eventually get them back, but not in a way that could be done during the match.

We’ve chosen to switch to digital beam break sensors, and they’ve worked smoothly ever since.

Programming

The programming team has been working on autonomous pathways for Waco, in between the changes to the robot that we’ve had to make. Right now, a three note auto is the highest we could achieve with the time that we have, but it’s worked consistently every time that we’ve tried it. The only issue that we’ve encountered was note decay. As the robot continually interacts with the note, it appears to undergo enough stress to create cracks internally. Then, when it’s shot, it finally breaks because of the force. We’ve slowed down the launcher to hopefully minimize this when we’re up close, but there’s not much else we can do to prevent the already stressed notes from not breaking again.

• Recap: Everything we’ve done in the past week has been either programming or testing for our first event in Waco. From testing the intake to calibrating the launcher, we’ve been busy. We’ve added supports for the internal intake, and we made the pulleys for the belts a bit smaller in diameter. We’ve also redone the wiring to account for the new sensors and added lights.

Programmers have made a couple of pathways that we can run, but they have mostly been focusing on the auto align feature. Now that all of the major issues have been fixed, we’ve been adjusting smaller things to make our robot just a bit better.

[LadyCans-FRC2881]

The team has competed at two FIT district competitions so far (Week 1 - Waco & Week 3 - San Antonio).

At Waco, we encountered many issues that we couldn’t easily work around. The robot was initially unable to pick up and score any notes because the handoff from the intake to the launcher wasn’t working as designed. During testing it worked perfectly, but because the notes on the field were so new the belts weren’t able to bend them around into launch position. We were able to score the preloaded note every match because it was already in the launcher, but after that notes got stuck. Once we had a long enough break between matches, we took some extra belt material that we had on hand and melted strips onto the existing belts to make ridges (with a soldering iron). These ridges helped to move the notes to where they were supposed to be, and we were able to score the notes that we picked up.

We fully redid the belting system running the intake after Waco by adding more permanent ridges to the main belts. This ensured that we wouldn’t have any more issues moving the note from the intake into the launcher while the notes are still fairly new. Additionally, the intake could originally pickup from both sides of the robot, but we blocked one side for our competition at San Antonio. This made the path for the note to travel much flatter, so it wouldn’t need to bend to get into the launcher.

We also added guards to the outside of the launcher to prevent the note from exiting the launcher in the wrong places accidentally. This worked perfectly, and no notes got trapped inside of the robot during a match that we couldn’t quickly get back out.

During the endgame, our climb currently works in two stages (may soon be changed). The second stage moves up with the first and eventually locks all the way up. At Waco, we had an automated program to run this faster than it would go manually (although it was still slow), but the program didn’t go high enough and the top stage wouldn’t always lock on the first try. The trap mechanism on the top was also too short, so we weren’t ever able to score a note in the trap because of it. So, we changed the reduction on the climber to make it move much faster. We also extended the trap mechanism more towards the middle of the robot, so the robot wouldn’t need to tilt as much when we climb.

In our first match at San Antonio (Qual 6) we got 9 points in the endgame (climb, trap, and the robot was spotlit). After that, lining up to climb became more difficult (so we missed the trap), and in many of our matches it was more beneficial for us to continue to score instead of climbing. We needed to pick up a note from the source in order to score in the trap, and that took too much time to do reliably.

An issue that popped up in the middle of qualifiers at Waco was that our guide intake got in the way of our climb. It got stuck on the underside of the stage, and prevented the robot from going as high as it should’ve been. We took it off mid competition, and the team made the decision to keep it off permanently because we weren’t using it yet anyways.

It also appears that something was messing with the gyro (causing gyro drift), so our autos were messing up, and the robot wasn’t driving correctly during our later matches. Now, we have a button specifically to recalibrate the gyro right before a match. At one point, the robot was moving too fast for it to pick up the April Tags on the speaker, so we switched to scoring from the podium. Then, programmers adjusted the location and calibration of the two April Tag cameras that we have on the robot to better see the tags when moving.