7492 CavBots - 2023 Build Blog

Hey, everyone! FRC 7492 CavBots, is excited to say that we will continue being a part of the #OpenAliance for the 2023 - Charged Up season, and hopefully for more years to come!

For some context - we were started in 2019 in The Woodlands, Texas, a suburb right outside of north Houston. This is our second year doing open design, prototyping, and programming - last year our previous writer “Boomie” graduated from the team. So we, Ninette (Co-Captain, programming & electrical) and Joey (Co-Captain, mechanical), will be taking over his duties and hope to be just as descriptive, truthful, and helpful. We plan on being transparent about the team, sharing both the good and the bad, so others can learn from what we encounter and struggle with throughout the season. We loved doing the build blog last year as it helped our families, teachers, and sponsors feel more connected to our team.

Good luck to all the teams competing next season!

We will be competing at:

  • Channelview - March 10th - 12th (Week 2)
  • Amarillo - March 30th - April 1st (Week 5)
  • Hopefully FiT District Champs and World Champs!


Google Drive - Will have all of our public files: including CAD (STEP files every few days, and upon request the original SolidWorks files). As well, we will upload our photos and videos so you can see our season progress. CavBots - Google Drive

GitHub - This is our public code repository so as the season progresses our code will become more complex and advanced. CAVALIER-ROBOTICS · GitHub


More resources:

Website - https://cavbots7492.com

YouTube - We will upload our 2022-23 chairman’s video here, and hopefully do competition recaps as well! https://www.youtube.com/channel/UCJYdM5ucSG2sFMD3Sy4ARrA


What a great and ENERGETIC kickoff!

We spent a couple of hours and came up with a few designs, some for the primary mechanism/elevator (extend out of the robot) and some to grip onto the game pieces. All of our ideas are located on our google drive. Here is what we have come up with so far!


MAIN COMPONENT/ELEVATOR: We will have two vertical, aluminum tubes –pink– that go about 4’6” (the max start height, and tall enough to be at the height of the cone nodes), then we will have a carriage –blue– that will go up and down with a chain elevator. Then, we will have a horizontal telescoping tube –green– that extends in and out, this will have our gripping mechanism attached to the end. As well, we are designing a rotational axis so that we can access both the game pieces on the ground and at the human player station. During the end game, we will rotate the horizontal, telescoping arm to be vertical so that we can balance better on the charging station.


GRIPPING MECHANISM: Our first version of our clamp is to have two curved, aluminum pieces that have compliant wheels on the ends. This will open and close with a servo, and have a 180-degree rotation with a neo550. The other gripping device we are planning on prototyping has one straight polycarb piece and one curved piece (will move in and out to close onto the game pieces).

EXTRA IDEAS WE ARE PROTOTYPING: We are going to test a way to move the battery along our belly pan to help with balancing (we call this the “electric slide”). As well, we are playing around with making two levels in our belly pan - one for the electronic and one for mechanical components (as well as a place to place a game piece as we drive across the field). We may look into a vacuum system to suction the game pieces; however, that testing will come later.

It only makes sense to discuss some strategies for this season.

  • Additional cameras on the robot to have better visibility when picking up from the human player station and while scoring.
  • Be adaptable, as the key factor of this game is cooperation. Everything is teamwork-based, so we must work closely with our fellow alliances.
  • Try to design a way for the robot to be self-balancing (automated).
  • Cones will be dropped and it will be faster to pick up horizontal cones in the middle of the field than go to the other side to pick one up from the human player station.

Over the next couple of days, we will be working on CAD, creating prototypes, and hashing out the details.

Thank you for reading! Let us know if you have any questions, concerns, or feedback.


We are currently stuck at a crossroads regarding robot design - if we should continue with our complex yet precise design or go with a simple but effective one.

This is a schedule for the season leading up to our Week 2 Competition - Channelview.

As we know drive practice is very important for this year’s competition: from coordination of picking up game pieces; to placing them without having a good view; and balancing on the charging station. Hopefully, we follow this schedule so that we have a couple of weeks for drive practice and fixing any bugs we come across.

As for the parts of the current design, we are prioritizing making sure that the design won’t damage any electrical components as it functions. As well, we are planning on prioritizing the vacuum concept of suctioning the game pieces as it is the most efficient method of grabbing the cones and cubes. Although, if we cannot realistically design the suction cups to work we will be using a gripper (we will start prototyping soon).

Here are some pictures of our progress so far…

We are hopeful that this design for the claw will be able to pick up the cones from any orientation as well as grip onto the cubes without damaging them.

Claw Version:

This claw will have an infinity belt connected to pulleys in order to get both wheels spilling in opposite directions. Then, we would plug a motor (using the empty bearing slot) and connect it to a gear, and those two would both be connected to the two pivot points of the arms. The arms would pivot with a 3D-printed set of gear teeth that surrounds the polycarb.

We will start prototyping it at tomorrow’s meeting!

Elevator: “simple yet effective”

Our “simple but effective” design for our elevator will have three stage elevator (two stages are shown in the picture) powered by one motor, and then have another motor power it to slant to the three degrees necessary (three limit switches to help program it) - one to grab from HP, one to score, one to pick up game pieces from the floor.

Elevator: “complex yet precise”


Our “complex yet precise” design for our elevator, carriage, and arm mechanism appeared to have many failure points that were caused by intricate and not easily replaceable pieces (if something were to get damaged in competition). We currently have this design on the back-burner, but we may go back to it in the coming days.

Vacuum Research:
We have spent many consecutive hours researching vacuums and the perfect way to suction onto the game pieces - debating how much surface area is needed to get an airtight seal as well as have the strength to hold on while moving at high speeds. We will start prototyping this design once we receive the vacuum pumps and all the parts necessary.

“Electric Slide”:

This will be using a rack n pinion to move the battery along the base of our belly pan, we are going to test if moving the battery can help us balance on the charging station. This picture is not the final design, but we are ready to prototype it.

Additional CAD Concept Video:
We have also been playing around with this gravity-moving, infinity ring which may come in handy with our future designs. This can act as a lazy susan or even an alignment corrector (due to gravity).

Just as last year, we have our progression posted on our google drive of cad Let us know if you have any questions. Good luck, and thank you for reading!


Now I gotta say these OA posts are definitely hectic, because my team continues to change directions for our design. However, I do believe that this post encompasses our FINAL concept!

The Field:

We decided that we will be building the WHOLE field rather than just half, this way our team and 1477 can practice auton routines for both alliances (since the field isn’t symmetrical). On Saturday, we built both of the grids and will get to building the charging station soon.

Our Vision:

Our ultimate vision for this design is for our claw to NOT rely on accurately aligning with the game pieces. We want to quickly and effortlessly grab onto the pieces without having to do any precise maneuvering of a claw or robot. We also believe that we should create a simple elevator system, just in case a part breaks in competition they are easily replaceable. As well as, we want the driver and operator to focus on QUICKLY picking up pieces rather than moving all the components of the robot.

Vacuum testing:

Vacuum Testing #1 - cone

Vacuum Testing #2 - cube

Vacuum Testing #3 - cube

Vacuum Testing #4 - cone

We have tested with large and small suction cups and have found that the smaller ones take less time to grip on and have a stronger hold.

Our priority claw design:

We call this design the “Kraken!” This may not be a water game, but we are definitely designing a sea monster. Just as a Kraken’s tentacles have many suction cups to grab onto ships and sink them, we plan on having multiple suction cups powered to grab onto the game pieces (we will have nine vacuum chambers). Our design consists of, nine suction cups: eight fingers that have joints/hinges moving with gravity; another suction cup attached to a spring concept that is in the middle of the octagon. This claw will be attached to a lazy susan and wrist so that when we orient the game pieces in a vertical position - gravity will rotate it to make the base of the cone closer to the ground. We will be shortening the “fingers” of the Kraken, as we have noticed during prototyping that we will have more contact with the game pieces if we do.

Backup Design:

We also have prototyped our backup claw design in case the Kraken doesn’t work. However, we are seeing great progress and positive feedback from our primary design.

Thank you for reading!


The suction prototypes look very interesting! Do you happen to know the p/n for the large diameter blue suction cup from the first set of tests? Thanks!

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We ordered “slip-resistant vacuum cups” p/n: 2135A16


Field Progress:

As I had previously mentioned in the other post, we decided to create both sides of the field. We completed the charging stations! Now we need to place polycarb on top of the wood to simulate the friction that it will have on the competition field. We are really excited to start working directly on the field with the Electric Slide, the arm, and of course the Kraken (claw) and prototypes.


Salf-balancing Robot: Code Version #1

Over the past few weeks, we have been updating our code to be set to 2023 and teaching our new programming members how to organize command-based code structures. Our programming team has been playing around with self-balancing code for our auton routines. Today, we were able to test it out on the charging station and it worked! Now we will be working on AprilTags: trying to code coprocess python on our drive computer (rather than using a Raspberry PI and PhotonVision’s Java libraries - although that is our backup).


We have updated our schedule to fit our new design (will post about it soon) !

Let us know if you have any questions, comments, or concerns!


I love the suction concept! I am wondering how you are generating the vacuum for the suction cups and if you are seeing any losses when adding multiple suction cups together?


Great question! We are generating the vacuum for the nine suction cups with nine different vacuum pumps all powered by one motor (we are 3D printing the housing for them). When testing we found that if you have multiple suction cups on one pump, you run into issues - specifically that we must have each suction cup in contact with the surface to have a tight suction. Our method will make it so that if one of the arms of the Kraken doesn’t make contact with the game pieces we will be able to continue to have a tight seal and suction onto them. I hope this helps!

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You guessed it… we changed our design again. However, we have learned a lot throughout the process and are excited to move forward with our current robot design.

Arm Base Design:



Our team has been going back and forth on how we are going to extend out to reach the grids - but we have come to a design that we all agree on. Our design consists of two triangular supports, they are connected by a hex shaft that will pivot the arm, and the motor that runs it is at a 160:1 reduction.

The issues we found out for our other elevator/arm designs:


  • Too complex; hard to replace pieces that may fracture during competition.
  • Difficult wiring plan; all the rotating, extending, and moving up and down made the electrical components at risk to break.


  • Approach angle; the angle to reach game pieces from the ground was not ideal for the claw.
  • Weight; the elevator was too heavy when fully extended and could risk tipping over.

Arm Extension:

Each arm has integrated C beams that have built-in tracks/rails. We are utilizing the inside of the C shape to put a pulley and belt system with a clamp attached to the belt - that will move the carriage and in turn, move the polycarb. Later, we will connect the two arms with a shaft in between - each arm will be powered by its own NEO Motor and tuned with PID to move at the same time.

Kraken Vacuum 2.0 Design:

Kraken 2.0 proved to be more effective than our previous design.

Kraken 2.0 Vacuum Testing


We are 3D printing pieces that are shaped to have a similar curvature to the outside of the cone. We will create three of these “three-leaf clovers” and attach them together as they will be our gripping mechanism. Our vacuum system will have nine suction cups, nice vacuum pumps, and one RedLine Motor.

Thank you for reading! Let me know if you have any questions.


Your arm frame looks like a great start, but I’m concerned about the live hex shaft. Because the moment arm on a telescoping arm is so long, that shaft might get chowdered.


That part specifically is not our final design, but just a placeholder. We will be designing it soon when we combine all of our designs into the master CAD.


This is our 3D-printed housing for our NINE vacuum pumps!



Kraken Update:

We 3D-printed our Kraken with TPU filament. We found that the flexibility of the structure works really well when coming into contact with the game pieces. We are currently designing the wrist that will connect the Kraken to the arm (updates coming soon)

(picture backdrop courtesy of Fatima’s hoodie)

Kraken Placement on Cone

Kraken Placement on Cube

At every angle and placement of the Kraken we are able to get 4+ suction cups gripping the game piece - keeping our game piece secure on the arm.

Kraken CAD:

Random Pictures with Kraken

All of our CAD is up on our google drive (link posted in previous posts). Let us know if you have any questions, comments, or concerns.


Hands down the coolest intake I’ve seen this year


This housing looks awesome! What pumps are you planning on using?

Link to the pumps we used. They used to be half the price…


We have pretty much finalized our CAD!!! This a very exciting milestone that will now be the momentum that will push us into quickly manufacturing our “alpha bot” (a way to test out and find any issues with our mechanical and electrical components, without wasting too many materials).

Over the past couple of days, we have been creating toolpaths and perfecting small, but important details on our robot. We were having issues with our Nebula for a few days, which slightly postponed some of our manufacturing; however, the issue has been corrected so we will get to fabricating parts soon.

On to what we have changed and worked on since the last post…

Intake / Kraken:

Practice Run -




We have made the circles slightly smaller in diameter (3.66 inches) and modified the percentage of the TPU’s flexibility to 75% infill. As well, while we were testing out the prototype we noticed that the circles (that hold the three suction cups) were turning on the connection point, so we added a sleeve that is cut at an angle to prevent the parts from twisting and turning.

Connection to Intake / Kraken

Connection - Lazy Susan and Disk Video

We have designed and created the connection for the Kraken. It has two parts: the first is a lazy Susan rotating on the outer rim, and the second part is a 3D-printed piece with a disk that can rotate roughly 28.6 degrees. The lazy susan is to orient the cones to be in a vertical position - gravity will rotate it to make the base of the cone closer to the ground. The rotating disk component is for if we want to attach to a cone that is on its side, we can slightly modify our approach angle without any motors.


We have kept the design pretty much the same with the dual, connected arms but changed it from being powered by two Neos (as it was wayyy too much power) to one Neo on a 90-degree gearbox.

Master CAD:

This is our finalized design, of course, if we notice any major problems when designing and testing the “alpha bot” we will adapt and change the components. However, I am very excited to see this robot’s design come to life. We have never had so many designers and members contribute to designing the robot - it is truly amazing to see how much they have learned throughout the process!


Auton Testing Video

Auton Testing - Side View Video

We are now able to follow a path that we designed on path panner (we are still fixing some bugs), but for the most part, we are seeing serious progress with our autonomous routines!


We have been discussing and planning out where our electrical components and wires are going to be placed on the bot: to prevent damage; have easy access; and be easily replaceable. We have decided to mount most of the electronics on the inside of the polycarb pieces that will be attached to the triangular base of the arm.

Late Nights Call for Pizza

Over the off-season, we built benches for Grimaldi’s Pizzeria - and in return, we get free pizza!

Thank you for reading