FRC 2869 - Regal Eagles - 2022 Build Blog

I know it’s a bit late, but here is our build blog as found on our website: https://team2869.org/build-blog/category/2022/

Week 1

Our team watched the kickoff live stream for this year’s game. This was the beginning of our build season. Right after the live stream, we read the manual and brainstormed ideas for our build season. A big thank you to the parents who helped us out with ideas and planning for the Rampage. We’re so excited to build this year’s field for Rampage! We started off by drawing some ideas on a SmartBoard and brainstorming some ideas and techniques having to do with intake. We then had a prototype for the shooter started and a possible design for a rotating intake arm. The mechanical group measured the dimensions for the chassis so that it would fit the dimensions that we wanted. Electrical was soldering the motors to make a prototype shooter for our robot. While that was happening we were looking for parts to build our climbers.

Some motor math:

  • A mathematical model, looking at different parabolic trajectories, leads us to conclude that we need the ball to move at 8 m/s. The max free speed of a 775 pro motor is over 18,000 RPM.
  • If we run the motor at 75% max RPM and a 10:1 gear reduction we get: 0.75(1800) = 1350 RPM. Attaching a 6″ diameter wheel to this motor, we get 1350 RPM (6in * 2 Pi) * 60 sec ≈ 10 meters/second

The first shooter prototype is complete. The ball was shown to exit near the speed we predicted. This was powered by two 775s geared down 5:1. (The shooter is flat, but we elevated it with the 3.5″ side of a 2 by 4). We also started assembling the chassis. Our carpentry team started reviewing the PDF file TE-22173 for measurements. The electric team worked on attaching neo brushless motors and toughbox mini to the new chassis.

Week 2

We prototyped two shooters and made the right adjustments to reach the high goal with both. We advanced our progress on the chassis with the toughbox mini and tube neo brushless motors. Our electrical team made an electrical panel to test the chassis. We also looked into using falcon 500s for shooters instead of the 775 pros. We tried putting new wheels onto the shooter prototype. The shooter prototype reached up to 8 feet in the air when shooting!

https://youtu.be/Qpp19WjvhJk

https://youtu.be/rNvtkeZqyAM

Then the chassis measurements (churro length) were fixed. We also continued to make adjustments to the two shooter prototypes. Meanwhile, others in the mechanical team built a climber prototype.

https://youtu.be/Eh8fDiuxK6w

We ordered materials we needed for the climber as well. The climber prototype worked as a proof of concept. A group brainstormed intake mechanisms. The electrical team researched encoders and practiced putting them together. The programming team tested out the Falcon 500s, and the CAD team designed and printed a mount for the Falcon. Programming also looked into tracking the ball through vision; pictures of the ball in different locations on carpet with scrap wood were taken. The climber group added a PVC pipe paracord system to the prototype hangar.

The PVC pipe is extended which is connected to the paracord raised by a roller similar to the 118 EveryBot 2020 design. The electrical group mounted the electrical panel to the chassis so we can hopefully start getting driving practice soon. The shooting prototype group built and fixed up the second prototype shooter. The intake group started the prototype for an intake design and assembled miniature tennis balls. The programming group got the UltraSonic sensor working for distance measurement.

This is our updated climber prototype
https://youtu.be/PYOcCzmqRsY

Week 3

Carpentry has made progress on making the field for our Regal Eagle Rampage on March 6th, 2022. Our carpentry team has just about finished cutting all the pieces of wood to complete the Hub, and now we are in the progress of assembling the field. We have made progress on our intake prototype and now it takes in the cargo efficiently. After seeing kickoff this year, our team decided that a vision system was going to be a necessity. We bought a Limelight back in 2020 but didn’t have time to actually use it. The Limelight contains a camera with some very bright LEDs on it, which make retro reflective targets shine very brightly.

The Limelight also has built-in software that filters out what parts of the image are from retro reflectors and what parts are unrelated. Then there are a bunch of options to narrow it down to just the targets you want, such as aspect ratio and area. But this year there are many targets in a circle, so the shape you get isn’t going to be dependent on the position of the Limelight, both in distance and height. Instead of selecting the target that is biggest or closest to the center of the screen, we ran two pipelines that detected the leftmost and rightmost targets, and the distance between them. We reasoned that if we knew how far away the two edges of the vision targets are we could compute the distance to the hub. However, turning that knowledge into an equation proved to be harder than predicted. We deduced that the graph comparing size on the camera to distance would be an inverse relationship since when the camera is closer to the vision targets, they will be more pixels away from each other (the image is wider on the screen). We just took a bunch of measurements and plotted a graph to fit.

As predicted, the graph was in the form we expected. The x axis is the distance between left and right (pixels), and the y axis is the distance to the target (cm). Just look at that regression! The R² is 0.999. If it were any higher, we’d have to assume this data was fabricated instead of collected by taking honest measurements. We didn’t figure out how to do it the proper way (with math) so if anyone wants to figure out why 9471/x is the correct formula, the distance between the center of the leftmost and rightmost is about 137 cm. If not, trial and error has been shown to work really well so we might just use that once we have a replica hub built.

We tested how high up and how far back the shooting/intaking mechanism should be mounted. We started off by doing some trial and error, then we modified certain lengths until we decided on a reasonable height and distance that allows the mechanism to intake while completely inside the frame mechanism. This is still just an idea …we need to check to make sure that the intake angle works, then we will verify our calculations in cad. Mechanical team has been making the mounts for the falcon prototype shooters. The programming team has made progress on our robots autonomous mode.

The programming team has worked on UltraSonic, which measures how far away you are from the object so it can stop at an exact point. They have also worked on PID, which determines how fast the robot needs to move to get to a specific spot. These programs help the robot start and stop at certain points, calculate the distance between the robot and the object, and determine the speed at which the robot needs to move at to get to the desired spot. They also have done some Artificial Intelligence.

The mechanical team has been working on a possible intake for the robot. The plan is to mount brackets for the rollers of the intake which will help the robot pick up the ball. We had planned to use carpet originally but changed our idea to rollers with rubber on them which helps with traction with the ball. A CAD design has been made for possibly having our intake double as a Falcon-powered shooter. A lot of metal has been cut the last couple of days for the shooter so it is an ongoing process. The electrical team has been designing the layout of the electrical components on the Lexan panel for the robot. Carpentry still is hard at work at making the proper parts for Regal Rampage, our practice competition before the real deal.

We are open to any feedback you have and we will be able to answer any questions that you may have.

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Week 4

This week we programmed our robot to be able to do 90 degree and 180 degree turns for the driver to use. We also have a feature for the robot to sort of parallel park to make the job easier for the driver. This feature can be used so our robot can be placed in the proper position so we can get the most accurate shot.

Our electrical team has finished the electrical panel for our robot. We are getting ready to place the panel on our robot since we have decided to use a C-chassis. This design will help our robot with the intake. We have made a lot of progress on our climber and shooter for the robot. We were originally planning on using the intake as a shooter but we started making another intake prototype. We have pretty much finalized our shooting design so we are going to be making the actual shooter sometime soon. Our hangar prototype was a success so a part of our mechanical team has been working on the full-sized hangar. Now we are making the arms for the robot. This will be used to move the ball to the proper angle to be shot at.

Our carpentry team’s progress on our field for Regal Eagles Rampage has been phenomenal. We have many of the pieces made out of wood for our field for our Week 0 games of the season. We are getting ready to assemble these pieces of wood into full game pieces.

Two of our sponsors named Vengo Labs and Alegna Soap came to visit us! We showed them our process in building our robot and our work ethic. Then we took pictures with them.



5 Likes

Could you please go into further detail on how this works? And it sounds like you’ll be doing this during teleop?

Sure, so basically the robot will turn about 45 deg then it will move backwards so it moves to the left/right and then turn back and move so it is in the same spot but moved over some amount. This will likely be implemented on a button so the drivers can use it for aligning to the hub and cargo.

Week 5

We calculated the gear ratio for the moving arm by finding the torque and looking at the motor curve. We decided not to use external gears and just use gearbox and sprockets. Here is some of the Arm Gear Motor Math:

Arm Weight:
2 775 motors: 1.7 lbs
2 falcon motors: 5.47 lbs
4 white wheels: 2.32 lbs
2 x 16 ⅛” cross bar thick = 176.9g or 0.4 lbs
Shooter plates (x4, ¼” thick aluminum) = 5.5 lbs (probably less)

Shaft collars & more:
6” 2 by 1 (⅛” thick) aluminum = 0.46 lbs
Shaft collars x 10 = .045 lbs x 10 = .45 lbs
Hex standoff bars x 24 = 0.8366 → 0.85 lbs

Total =17.15 lbs or 7779.1 grams (7.8 kg)

Torque:
Torque = Fd = (78 N)(0.15 m) = 11.7 Nm
Torque = (17.15 lbs)(.5 ft) = 8.575 ft lbs

Screenshot 2022-02-13 110250

One nice thing about this design is that we can easily increase the torque by changing the gearbox since we are starting here with a very low output ratio.

We should observe how different these theoretical calculations are from the actual movement. We do not plan to run the motor at full power, which may double the time. The control code needs to slow the arm down as it gets closer to the desired position, and that will increase the time.

Another concern is the current draw to hold the arm in place. We need to keep this down so that the spark doesn’t overheat and we need enough power to run the shooter motors.

Current draw testing idea:
We previously ran the 2018 bot with the mini Neo and used the breaking function to hold the arm into place. Let’s do that again and check the current draw logs. Then, let’s pull that gearbox apart, see what the ratio is, and see how much the current draw changes if we increase the ratio.

Using the CNC machine, we cut plates out of Lexan for testing before setting it for water jetting. The programming team worked on the vision system for the robot. We finalized the dimensions for the shooter plates to be sent out for cutting. We used CAD for the moving arm of the robot. In carpentry terminal 1 was built. The arts and crafts team is painting the Rapid React for the lower hub pieces that the carpentry team is building.

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Looks great!

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Week 6

The carpentry team is putting the final touches on our Rampage field. They completed building the second terminal and the hangar for our Regal Eagle Rampage field. Arts and crafts spray painted the hangar bars blue.

Our blue hangars for Regal Eagle Rampage!

The mechanical team used our CNC to prototype the moving arm and after it connected to our sprockets, we considered just making the plate out of ¼” Lexan. We planned to use #35 chain to move the arm and unfortunately only realized on Saturday 2/12 that we do not have any #35 sprockets. And so our build week begins with us waiting for some essential supplies. Sprockets were ordered, along with parts for a gearbox for the climber. LPR precision should have our ⅛” aluminum plates ready by midweek.

We got our water jet cut shooter pieces and assembled the moving arm centerpiece. We also tested the encoders and are continuing the separate intake mechanism. After, we assembled and tested one side of our shooter and attached the arm bar to the moving arm assembly. We have a PVC intake using a 90 degree gear stage (versa planetary) for the motor gearbox mounting to the sprocket. The mechanical team measured and cut metal for the arm supporting structure and we experimented with capacitors for the LED vision system. We tested the spinning of the wheel on our shooter.

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Week 7


Deciding where to place our cargo shooter on the robot.

We mounted the structure that holds the arm for the robot. Mounted the motor for the separate intake with a 40 degree angle guide to push the ball to the center of the chassis for proper use.


The intake with the design to move the ball to the center of the chassis for the robot.

The mechanical team assembled the shooter and mounted it onto the moving arm of our robot.


The shooter for our robot.

Then we tested the shooter of the robot. As well, we cut the Lexan and mounted the battery mount for the final electrical panel of the robot. The programming team continues to further develop the robot’s vision system.

Our Lexan was cut for the electrical panel, we mounted the electrical panel and added the electronics. A bar stock was added for support. The mechanical team continued to cut and mount the arm structure but there was some trouble with bracketing and getting 90 degrees with the bandsaw while our miter saw was out of use. We finished building our climber for the robot. We finalized the length of the arm of the robot. We experimented with flashlight and capacitors and found that using resistors bundled together without a capacitor fixes the pulses in light intensity. We decided to use the shooter as an intake while testing the it.

Robot intaking.

We finished cutting and mounting the arm structure. We mounted the motor on the climber and finalized the position on the chassis. The electrical wiring, mounting, and soldering is finished.


Robot


Shooter/intake


Electrical

Components of our robot

We completely assembled the robot and the IDs were set for the motor controllers. We started making new bumpers for the robot. There were some finishing touches to our hub for Regal Eagle Rampage and painted wood for our field for Rampage.


Hub


Hangar

Parts for Regal Eagle Rampage

sorry for the late week
Week 8

We are testing and adding the finishing touches to our robot to prepare for Regal Eagle Rampage and for our competitions! We added a top guide for the shooter when it fires.

Electrical team finalized CAN bus together on the electrical panel and mounted the spark max and talon motor controllers for drive train and climber. We started mounting the climbers on the robot.

We are working on the bumpers for the robot and we put them on to be prepared for our Regal Eagle Rampage.

Our robot for Regal Eagle Rampage! We are prepared!

Week 9

This Sunday, our school hosted our 4th annual Regal Eagle Rampage! As a result of all the hard work our members put in, the event came to be a total success. We had a grand total of eleven teams from across Long Island attend Rampage, each of which showcased their own unique robots to play Rapid React in a field built entirely out of wood! Thanks to the combined efforts of our carpentry team and our parents, the creation of the field was made possible. We sold many treats and snacks so our competitors and teammates would not get hungry after a long day of competing. We hope that all the teams that attended had fun and we hope to see you next year!

Pictures from Regal Eagle Rampage!

After the competition we started finalizing the climbers to put on our robot to be prepared for our regionals. We created the mounts for the climbers and put them on. We bent another piece of bar stock as a guide for the shooter. We put lock tight on our screws on our robot and are making our second set of bumpers which are the red ones since we only had the blue bumpers before. The programming team is fixing and editing the autonomous code so it will work better and be consistent.

Red Bumpers

Climbers being assembled

With all the progress and preparation for Hofstra, we created a scouting app to help our team members scout better and make it more easier. This is the link to the Scouting App.

Scouting App pictures

Week 10

The electrical team is learning to use a limit switch to put on the robot that senses and says when a component is touching or not and it prevents mechanisms from maneuvering too far in one direction or the other. We are also making adjustments to our bumpers so it will fit on the robot better. We have both of the climbers mounted on our robot to make our robot climber at Hofstra. We are rearranging our cables on our robot so that none of them get in the way of the movement system like what happened in one game at Regal Eagle Rampage. We are attaching the sparks that control the motor and are swapping the victor for a talon (for the flashlight for ball tracking). We are also wiring the spark max for the second climber.

Climbers

Reorganizing cables

Our robot can now climb and hang on the hangars!

We are just adjusting the flashlight on the robot and preparing for Hofstra! We also have an AR App! The AR App allows you to see a virtual image of the hub. This allows you to not have to build your own hub and you can see how far and if your robot would make the shot. This app is efficient and it allows other teams to not have to spend and waste the resources to make their own hub when they could have a virtual one. This app is very easy and fun to use.

These last weeks have been very fun and we are super excited to go to Hofstra! We have come a long way and we hope all of our work pays off!

Week 11

This week we started of preparing for our Hofstra Competitions but testing and driving our robot!

Our journey at Hofstra started off with SBPLI #1 from March 21, 2022 through March 23, 2022. After 82 qualification matches spanning 2 days, we were chosen by the eighth-seed alliance Team #7567 (Sesi Senai São Paulo Octopus from Brazil) and Team #2875 (Cold Spring Harbor), and went onto the quarter-finals! We also won the Judges Award, an award given to teams by the judges panel to recognize a team’s unique efforts, performance, or dynamics merit recognition. Even though we did not win we noticed and fixed some problems with our robot to be prepared for SBPLI Regional #2.

Following SBPLI Regional #1, we participated in SBPLI Regional #2 through March 24, 2022 through March 26, 2022. During our qualification matches our robot’s intake and shooter got bent which worried us a lot. Thankfully our drive team was quick to problem solve and we were back on the field. We ended off the day completing 48 out of the 69 qualification matches.

Week 12

After 69 qualification matches, it was time for alliance selection, where we were picked by the 1st seed alliance led by StuyPulse (Team 694) and Team R.I.C.E. (Team 870). One of our alliance partners fell during one of the final matches and cracked their shooter. Even though that unfortunate event happened, the alliance went a perfect 6-0 during each of the best-of-three playoffs series (Quarterfinals, Semifinals, and Finals) to earn the right to participate at the FIRST World Championships!

The Regal Eagles were also the recipient of the Engineering Inspiration Award, which is given to a team that “celebrates outstanding success in advancing respect and appreciation for engineering within a team’s school or organization and community.” As a recipient of this award, NASA will cover the registration costs for the Regal Eagles to participate at FIRST World Championships.

After these exiting events we only had a week until we had to ship our robot to Houston, Texas for Worlds. During this time we tweak and tested our robot’s driving and shooting. We are very exited to be participating in World Championships this year!

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