FRC 611 Saxons 2024 Build Thread

Welcome to Team 611, the Saxons, 2023 Offseason Build Thread. We are a student-led school-based team operating out of Langley High School in McLean, Virginia. This is our 23rd year as a team and our first year on open alliance. As we share our robot this year, we hope to be helpful to your teams and induce the creation of better robots. There will be updates once a week working on a Wednesday to Tuesday schedule with updates on every Wednesday, although this may be subject to change based on the amount of information we have to share. We are attending VAPOR in week 2 and VAFAL in week 4. This year, we plan to keep our robot simple but effective, and most of all reliable. As public documents get created, we will post them here. Special thanks to our sponsors Leidos and Lockheed Martin for supporting us. We look forward to having a great season and wish everyone the best of luck.

Github:SaxonCode

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611 | Week 1

Welcome to 611’s first build season update!

Kickoff

To start off Week 1, we met on Sunday (1/7) for a kickoff design
and strategy meeting. We started with watching the game video all together and outlining overall design goals and major design restrictions from the game manual. We then broke out into small groups to create initial designs, with each group presenting their design and getting feedback/questions from the rest of the team. We’ve found that having students split into groups and making a quick simple initial design is great at giving students experience with creating ideas and communicating them to the group. Here are three examples of design ideas that team members created:

To start our initial game analysis, we created a quick table of common ways to score points to see which scoring methods are the most valuable. Our thoughts were that quick amp and speaker cycling would be important to amplify the speaker as many times as possible to quickly gain points.

We also discussed a list of qualities that we wanted to guide our
design, which were:

  • Fast cycle time
  • Consistent shooting and scoring
  • Low height and center of gravity
  • Be able to score in speaker and amp
  • Be able to climb
  • Simple overall design + minimal points of failure

We’re still considering the addition of a mechanism to score in the trap, but likely won’t create a mechanism for it in our initial design. We decided that the trap’s main use was earning the endgame ranking point, but didn’t have as much value points-wise, and adding an additional mechanism for it would add more complexity to our design.

Season Organization

Within the first few days of build season we also set up monday.com as our organizational software. This is our first time using a dedicated software to organize/plan our tasks and meetings, but so far it’s been really helpful to organize each task and our goal for when it should be completed. Here’s how we set up our table:

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In case you don’t know FIRST teams can get the non-profit version of monday.com for free, so if you’re considering using it make sure you take advantage of this!
https://www.firstinspires.org/robotics/frc/blog/2023-monday.com-is-back

Week 1 Building

We’ve spent the first few days prototyping and brainstorming designs, using inspiration from other teams in OA or Ri3d to create prototypes and decide on a design. We’ve been slightly limited with testing prototypes as we unfortunately don’t have access to any notes yet (our kickoff kit was delivered and so hasn’t arrived yet). We’ve since also ordered notes from AndyMark so hopefully we will get those soon to be able to test.

If you’re a team next season who is considering picking up vs. delivering their kickoff kit, keep it in mind that you may not have access to game pieces immediately! Next update we’ll be able to provide more prototyping and design photos as we progress.

We also constructed the amp so we could test amp scoring methods as soon
as possible. WIP photo below:

We haven’t finalized a design yet, however we decided that we’ll be using a swerve drivetrain and a COTS climb mechanism (specifically, the ThriftyBot telescoping tube). The benefits of having a reliable and easy to manufacture mechanism on the bot were something we wanted to repeat this year, especially so we could put more attention on other components and overall finish our robot faster.

Thanks for reading our update; let us know below if you have any questions, and good luck to all teams this build season!

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611 | Week 2

We started Week 2 by prototyping a variety of shooters and intake systems.


One of our initial design philosophies was to have as few mechanisms and moving parts as possible. However after the construction of our Amplifier Game Piece, it became evident that a simple shooter would be insufficient for the task.

Original Design

Our original design included an extremely tall shooter mechanism that would have vertical belts go all the way to the top and meet horizontal flywheel shooter. The design was similar to that of Cranberry Alarm’s Ri3D bot. This would allow us to shoot with the wheels into the amp, and roll with belts into the amplifier. However, this did not work with the dimensions of our robot so we had to scrap the design and move to something else in order to keep a small robot with a low center of gravity.

New Design

Our new robot design is very similar to the Unqualified Quokkas Ri3D design as they were a large inspiration for our current design. It features one large rotating arm with both the intake and shooter mechanism condensed into one mounted on the end. This will allow us to score in both the Amplifier and Speaker and make us fast in Autonomous as there is nearly no indexing time.


This also allows for auto-aiming during the driver control period. We hope to be able to score in the trap with this design depending on how the geometry works with our hook, but it is not a priority for us at the moment.

Mechanical

From a mechanical perspective, we were able to finish our robot chassis this week. We constructed a 26x26 inch chassis as it lets us be small and maneuverable. Furthermore, we constructed half of our rotating arm and have finished machining the parts for our intake and outtake mechanism that will be mounted on the arm.


Electrical

We have finished the assembly of our main electronics board. We will later mount this onto our belly pan. This has allowed us to more easily test our design using the motors that will be on the actual robot instead of drills.

Challenges

One of the largest challenges we have faced is trying to keep newer and less experienced members of the team engaged while also trying to make the best bot as efficiently as possible. We have rectified this by creating sub-teams and having newer members work closely with more experienced members to ensure the efficiency of the project. We have also had trouble with inclement weather which we hope will soon blow over, allowing us to make the most of our season.

Goals

We hope to finish the construction of our robot by the end of Week 3. We plan to begin thorough testing of the robot and iterations on the intake outtake mechanism. Thanks to 5549 we have recently received our first Notes. We highly recommend not shipping game pieces in the future and instead picking them up at kickoff as it has significantly delayed our progress. With these notes we hope our tests will go more smoothly and we will be able to make fast progress. We also hope to have the field game pieces fully built and ready for testing.

Links

CAD
Photos

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611 | Week 3

Welcome to week 3 of build season!

Mechanical

Our aim for this week was to finish assembling our intake/outtake mechanism so that we could test our shooting. We started off the week by attaching our arm frame to our drive train mounts.

We then moved to attaching the assembled intake/outtake component to the arm structure. This is intended to be our first version of our intake/outtake mechanism, and we’re planning to iterate it as we move forward and further test. The biggest part we’re looking to change currently is the mounting of our motors, which will affect our gear and belt spacing. This change will shift weight closer to the base of the arm and decrease the amount of torque needed to lift the arm which will let us run the arm faster.

The intake was assembled without belts since they had not arrived yet, so that is the last part needed to complete v1 of our mechanism.

We also used 3D printed custom spacers as belt rollers which so far have worked well with compression and holding belts. Our compression was enough to hold the notes without belts attached, so once they’re added the intake should have a solid control of the notes.

Electrical

This week we also did an initial wiring of our drivetrain on a temporary polycarb belly pan which was helpful to begin setting up electronics and our wiring layout. Our final plan for electronics mounting is putting them on top of a steel belly pan bottom with a polycarbonate cover to be both protected and easily accessible, so the electronic wiring and layout will be redone for the final version.

Programming

This week, programming focused on making sure our swerve ran correctly and prepared code for each mechanism, so that we’ll be able to test as soon as we get motors mounted. We’re also working on setting up basic autos in preparation for our mechanisms being completed, as well as our Arducam/Beelink Mini PC vision system in order to begin work on april tag and note detection.

Testing

We were successfully able to test the geometry and power of our shooting design. We tested shooting at angles for both the amp and speaker using drills to power the wheels. Drill powering the shooter still gave a powerful shot that was able to hit the height of the speaker and stably enter the amp from a close distance, which is a good sign for how the shooter will perform with motors attached. Here are videos of our amp and speaker testing:

611spkertest IMG_7639

Goals

Our goals for this next week is to mechanically finish mark 1 of the robot so that we can program and run into any potential issues with plenty of time to fix them. We’re still waiting on some parts to arrive to be able to fully assemble, so in the meantime we’ll be assembling what we can and iterating our intake/outtake design.

Testing early and often is a super important part of the building process, and something that we’ve tried to emphasize with our building this year. Design flaws and issues are much easier to fix earlier than later!

We hope everyone’s build seasons are going well so far. See you next week!

Links

Github
CAD
Photos

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Hi guys, looks like you’re making some great progress!

Are the shafts on your robot UltraHex? If so you might want to consider replacing them or having spares ready, UltraHex is 6061 aluminum instead of the 7075 of rounded hex stock.

6061 (top bars) is less stiff and less strong than 7075.


Link to material comparison

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Where are you guys planning on shooting from?

Hi,

Thanks for the suggestion. We are currently using UltraHex for testing purposes, but plan on switching it out for a steel hex shaft for the finished robot. We will definitely look into the rounded hex stock as another option.

We plan on shooting from anywhere within our wing that does not have line of sight blockers.

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Stiffness is really no different, only yield and ultimate strength.

611 | Weeks 4-6

Happy week 6 of build season!

Our main focuses for these past two weeks have been to finish assembling our main mechanisms, attaching everything to the main robot, and getting to a spot where we’re ready to test and practice.

Mechanical

Our mechanical team worked on completing assembly and refining our main intake/outtake mechanism. Our biggest changes were mainly our intake belts and motor placement/tension- we remade our intake belts and then moved our motors to the inside of our arm to improve the belt connection between the motor and shafts. We also moved to 2 wheels on each side of our shaft instead of three across because it led to better connection with the note while still conserving mass. We also installed our motors to rotate our main arm and changed the hex shaft to steel to be able to hold the weight required.

We also finished the main assembly of our climb, which we’ve kept from our initial design (telescoping tubes). We spent some time 3D printing hooks as tests, and once we attach the climb fully we’ll CNC a final version of the hooks out of polycarbonate. Photo below of our fully extended climb:

For mounting our climb, we bolted the first stage of the tubes to a short piece of versa, and then attached that to the drivetrain frame. We are looking to improve the mounting of this as currently most of the weight will be on the bolts attached to the versa piece, which may not be too stable when carrying the full weight of the robot. We also removed the second stage on each climb as the chain’s maximum height is 4ft off the ground which we would be able to reach with one stage.

We also finished the manufacturing and attachment of our belly pan so that we could start our final wiring. We used our paint method (painting bolt heads placed in the attachment holes and then placing the bellypan on top) to get accurate hole markings on a place that’s hard to measure. Thank you again to 8592 for helping and cutting our belly pan sheet for us!

Looking ahead, our goal for the next week is to finish attaching the climb early so that our full robot can be tested, as well as starting to work on iterations and backups of our main mechanism.

Electrical

We had to pause on wiring our robot in order to put on the belly pan, so once that was done we were able to finalize our robot wiring.

This week, now that we had motors assembled, we had continued issues with info wires on NEOS breaking from their connectors. Although they’re able to be replaced/sautered back on, it still is a setback, especially if the motors are already mounted/difficult to replace. Something that we’re looking to focus on in the future is trying to make sure that mechanisms are easy to repair/maintain during the design phase so that they’re more reliable and easier to fix. Along with this we’ve also been trying to emphasize to the team the importance of not pulling them by the wires themselves to prevent this in the future :slight_smile:

Programming

In these two weeks programming mainly worked on setting up some basic autos to test once the robot is driving. We also worked on getting the wheels to align on enabling the robot, in order to not have to restraighten the wheels before every match. More programming updates will come once we are driving and testing fully- here’s us doing some preliminary swerve testing.

IMG_7258-ezgif.com-video-to-gif-converter

Game pieces / Bumpers

During the past two weeks we also finished constructing our game pieces so that we’re ready for testing, as well as our bumpers.

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nice robot.

611 | Week 7

Welcome to Week 7 of the build season!

Our main goal for this week was to get a fully functional robot that could compete at our Week 0 competition hosted by Team 888.

Mechanical

Mechanically we finished the final stages of our intake and arm mechanism by tensioning the belts and chains to make sure that everything spins properly. We also cut ourselves some hooks and mounted them onto the telescope which was put onto the robot. We had some issues with the telescopes expanding which we fixed by using aluminum lubricant and extensively deburring all of our holes.

Programming

From a programming perspective, the majority of our effort was directed to setting up PID tuning for our arm and beginning to code our autonomous. With the limited time afforded to us we had not super fine tuned constants. Over the next week we plan to dial in our PID tuning and begin working on auto aiming for the robot.

Week 0 Competition

This Sunday we competed at week 0 hosted by 888. It was a great opportunity for us to test our robot and see how it would do in a competition. While competing there we realized that our long belts stretching across our robot were a liability. To fix this we will move our motors a lot closer to the top of our arm and shooter. We also found that although our hook could hang, it was difficult for the driver to see, so we plan to redesign it and make it easier for the driver to hang the robot. We also decided to move away from the belts and move to compliant wheels after speaking to some teams at the competition.

Hope everyone is having a great season!

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611 | Week 2 Competition Update

Hi everyone, welcome to our post Week 2 OA update.

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CHS Portsmouth Event Review

We competed last weekend and had a great time in the week 2 CHS VAPOR event! Going into comp, our goal was to be a quick and reliable cycler, both in the amp and speaker. We did well with overall note scoring, averaging about 5 notes per scoring match, and with our max being about 7-8 cycles.

We also came away from competition with a few ideas to improve our full cycling capabilities. For example, due to our intake being quick with ground-intaking notes, they would occasionally go too far and get stuck in the shooter flywheels. The flywheels then wouldn’t be able to provide enough torque to move them, and so would force us to either play defense or forcefully dislodge the note. We’ll talk more below about how we decided to address this issue. Here’s an example of this happening!

Although our bot was designed for scoring in both the speaker and amp, we found that often we focused on the amp during matches to fit our alliance’s capabilities. Overall more teams tended to be stronger with the speaker, which made us quite versatile with alliances. We definitely were strong throughout the event in providing consistent cycling, particularly with amp scoring.

Above is a small overview of our overall note scoring throughout the matches, which marks how many notes we scored in each match combined with our alliance’s total notes scored. We had an average of about 48% of our alliance’s total scored notes!

Pit and scouting management

For scouting, we collaborated with 5549 and used Scoutradioz for collecting data (for any other teams looking for a scouting software, we would recommend using it!). Since we have about 20-25 members attending each competition, we create a scouting/pit schedule to help organize our members and create a balance between our scouting teams and pit crew.

Another thing we implemented within our pit was pre-match checks- we created a pre-match checklist and assigned two pit crew members to go through it while preparing the robot. We wanted to minimize losses of functionality from known issues (eg. missing CAN connection, misaligned wheels) that could have been caught before a match. This has been an issue for our team in past years, and caused us issues both with limiting our scoring but also with being picked for alliances. Here’s an example of what our checklist looked like:

To finish off VAPOR, we ended alliance selection as 7th alliance captain, and had a great time with 1915 Firebird Robotics and 2068 Metal Jackets in the playoffs. Thanks to all the teams at Portsmouth for a great event experience!

Post Week 2 Improvements

Post VAPOR, we’re to improve mainly our autonomous and climb, as those were our two weakest points that would help us improve our overall scoring (especially RP) capabilities.

Last week we re-machined our shooter to add in bearing retention plates and extra stability, and then refined our climb. As mentioned before, to fix our issue of over-intaking notes, we chose to add an IR sensor (specifically, an Adafruit 5mm Beam Break Sensor), which also has the benefit of allowing us to expand our auto scoring capabilities.

For our climb, we designed a new hook with a wider horizontal reach to make attaching to the chain easier. Additionally we added absolute encoders to each climb motor so we could add in software extension and retraction limits, helping with our overall reliability. This week’s goals are to finish wiring and programming in our sensors, cycling practice, and refining our autonomous capabilities.

That’s it for this update–we hope everyone is having a fun competition season, and good luck to all teams this weekend!

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