6421 WarriorBots 2023 Build Thread | Open Alliance 2023

Welcome to the WarriorBots 2023 season build thread! We are so excited to be participating this year, we benefitted greatly from the openalliance teams last year and this is our way of saying thanks. Our team is based out of Muskego High School in Muskego, Wisconsin.

Here are all our main links:
Onshape
GitHub
Photo and Video Documentation
Team Website

@NYtoWI and I will likely be the main mentors posting and responding, alongside some of our students @Wesley_6421 and possibly others throughout the season.

Thank you to everyone who takes the time to look through our thread, we hope you find our season build thread helpful.

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6421 OA Update - 1/4/22

Last meeting we spent a lot of time working through a previous game and strategizing what different robot roles would have been in 2018, as few students have seen a pick and place game. This meeting was focused on explicitly listing out our high level goals for the season before we start talking about robot specific goals on Saturday.

High Level Team Goals:

  • Top 4 in robot rank
  • Target one Machine award and one attribute award, TBD as the robot develops, we won the Autonomous Award at Finger Lakes Regional and will likely target a different one for this year

Build Season Schedule:
Link to our Build Season schedule, we reassess it each Saturday afternoon, along with our robot goals

Big deadlines:

  • Week 1: Goals set, chassis built, big research push complete, prototypes underway
  • Week 3: Robot V1 mechanically done
  • Week 4: Robot wired, testing and iterating mechanisms
  • Week 6: Scrimmage Competition: 2/19
  • Week 7: Robot reveal party for sponsor/parents
  • Week 8: Northern Lights Regional (Week 1 of competition)

Build season team structure
Our team is split into 3 build groups during build season, with a mix of mechanical, electrical, programming, and business students along with a few mentors. Teams each have a student lead, and a documentation lead that handles taking photos/videos of everything. 2022 we had Shooter, Climber, and Cargo Handling, with things like drive train being handled on the side with free hands.

Shop Tour
General overview of our space and resources, photos here

  • 2, 3D printers
  • OMIO CNC
  • Brake Press
  • Mill
  • Bandsaw, sander, grinder, other benchtop tools
  • Assortment of Milwaukee Tools
  • Workbenches: 3 for the build teams, one for electrical/misc build assemblies. Each equipped with commonly used tools

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6421 - 1/11/23
Mid-Week 1 OA Update

I would like to start this update by shouting-out the Mukwonago BEARs, team 930, for hosting and inviting our team to their kickoff event this past Saturday. After the revealing of the game animation and an event-wide rules review, the teams then broke off into separate rooms for their own respective discussions. Our team discussed this season’s game, robot roles, and we finished our discussion by setting our robot goals for this season.

The first thing we discussed were the actions a robot may do in this year’s game. As shown below, we defined both positive and negative actions. Positive actions mean that a certain action would aid our robot in scoring or make it more difficult for the opposing alliance to score, and negative actions meaning the opposite.

The next thing our team defined was robot archetypes. The main reason we decided to define robot archetypes is because of this season’s complexity. In the 2022 season, Rapid React, almost all the top robots were completing both aspects(climbing and shooting) of the challenge; individual robot roles were not very prevalent. As we looked back at this season’s game animation, our team believes that there will be a larger presence of robots with individual roles within the top alliances, rather than alliances made up of two to three robots that can complete every task. With that in mind, our team defined the eight different possible robot archetypes that are shown below.

Finally, our team discussed our robot goals for this season. Our robot goals for the season can be seen in the photo below. For the chassis, we decided to go with Swerve due to its mobility and the rather open layout of this year’s field. We are aiming to have the ability to pick up both the cubes and cones regardless of position and orientation. For scoring, we are aiming to score on all three positions with our priority being scoring on the Top level of the Grid.

At the end of our Saturday meeting, we assigned our pre-determined groups of students into their respective subsystem teams. Our subsystem teams are as follows: Intake, Handling, and Charge Station. As our team does not meet on Sundays, our students spent time before our Monday meeting doing research into different mechanisms. With 31 different mechanisms researched among the three subsystems, we came into our Monday meeting ready to discuss the first steps towards building our robot. The subsystem teams broke out into our available work spaces and started to review, discuss, and analyze the different mechanisms that were researched. By end of our Monday meeting, all subsystem teams had narrowed down their discussions and started to conceptualize two to three mechanisms.

Our teams spent Tuesday doing further research and discussion, along with building some concept prototypes. By the end of our Tuesday meeting, here is what each team had completed:

  • Intake - The Intake team built two different concept prototypes. One that proved the applicability of a clamping end effector. The second was similar to the first prototype, but with free-spinning wood blocks as clamps. This was to prove a self-righting concept for picking up the cones. Heading into our next meeting, the Intake team will be working on a concept prototype focusing on a pinching/claw-like end effector.
  • Handling - The Handling team started a concept prototype for an elevator with an arm attached. The main reason for this prototype is to get final dimensions to our chassis team. Heading into our next meeting, the Handling team will continue developing their prototype with hopes of finishing their first prototype, then adding functionality to it. With the end goal of testing by the end of the meeting.
  • Charge Station/Chassis - The Charge Station team built the four Swerve pods we will be using on this year’s robot. Heading into our next meeting, the Charge Station team will start prototyping/designing the chassis with hopes to test the chassis before the end of the meeting.
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Highlight from testing today, tried a weedwacker intake similar to 4481’s and 2158’s prototypes with a ramp, a heavy spinning flap helped considerably :sweat_smile:
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Amazing use of KOP battery leads! Awesome!

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Something to keep in mind is the extension rules it looks like your flappers might break the projected planes from the sides of you robot.

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6421 - 1/15/22
Week 1 OA Update

Our team has spent the last half of this past week continuing prototyping, iterating, and testing mechanisms. Going into week two, our team plans to continue testing in hopes to have finished our first CAD model of our robot.

Intake - Coming into the Wednesday meeting, the Intake team split up into two groups to divide our focus. The reason for this is to allow them to more efficiently work toward the goals our team set for our robot.
End Effector Group - This group decided continue prototyping and improving the clamp-like gripping mechanism they had previously been working on. Following their concept prototypes, this group added a pneumatic piston to both arms to more accurately simulate the motion of the gripper. Finding that a singular piston did not have the range of motion needed to grab both the cube and cone, the group decided to attached a piston with a slightly shorter stroke onto the original piston with a slight offset to get the proper range of motion needed. After finding these tests successful, this group started their CAD design. Once they had a baseline CAD design done, the group started to test different gripping materials. They believed that a material that proved more compliant to the cubes and cones, while still having a better grip than the compliance wheels would be better for the gripper. Doing a small bit of research, on of the students came up with the idea of using the foam inside of a 2020 Power Cell game piece. After cutting up a Power Cell and attaching it to the gripper, this group found that the foam was a better material than compliance wheels. Heading into next week, this group plans to continue testing different materials in hopes to finalizing the CAD design of the gripper.

Out-Of-Bumper Group - The second group of Intake was focusing on an out-of-bumper intake to meet our goals of picking up game pieces from the floor and re-orientating them. This group started from zero and began researching different ideas. After some research, this team decided to prototype and intake inspired by RI3D Redux’s double roller intake. After some testing, they fond some down sides similar to what Redux had found, but still continued researching ideas in the background. The next idea they came up with was similar to team 2158, AusTIN Can’s out-of-bumper intake. Spending some time iterating this street sweeper-like intake with different materials(as shown below), this group found that the COT battery wires were our best on-hand material to use. This was due to their ability to flex while still maintaining a rigid form. Heading into next week, this group plans to continue testing and iterating their prototype with hopes to decide on a final design, and to start their CAD design.

Handling - The initial prototype for the elevator system was a two-stage system with an arm attached to a carriage, but after some testing we decided to eliminate the second stage. After adding the arm to the prototype, the Handling group worked on how to add a gravity counter-balance mechanism onto the arm. The team did some research and incorporated the counter-balancing system using a combination of steel wire and elastic surgical tubing. The Handling team has also started their CAD design, and will be incorporating the counter-balancing system once tests prove it effective. Heading into week 2 of build season, the Handling group plans to continue testing and iterating their design in order to finalize their CAD.

Charge Station/Chassis - On Wednesday the Charge Station group finalized the chassis dimensions and started to machine the 1x2 pieces needed. After putting the chassis together, the Charge Station team wired all the electronics needed and passed off the chassis to our programming team. Starting on their prototype, this team’s goal was to find some sort of mechanism that would allow us to balance easier on the Charge Station. After some research, the team came up with a slider-like mechanism drive by belts that would shift weights along the robot. After some testing and iterating, the team has figured out how to effectively move weights along a horizontal plane in different orientations. By using the gyro in NavX attached to the RoboRio, this team figured out that they would be able to self balance according to the angle of the robot. Heading into this next week, this team plans to finalize their CAD design and assist the other team’s in their processes.

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KOP cube got sliced in an intake prototype

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While iterating, our intake team decided to go another direction in their prototype. Rather than focusing on an intake that can only pick up in one direction, they started to do some research on mechanisms that would allow our robot to pick up while strafing and driving straight on. Taking inspiration from NRG, team 948, our Intake team constructed the prototype shown below. Here’s our first test of the system:

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After this first test, we adjusted the speed down a bit and now have a more controlled intake mechanism. I will be sending out an in-depth update about the first half of week 2 early tomorrow afternoon.

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6421 - 1/19/22
Mid-Week 2 OA Update

Our team has spent the first half of week 2 continuing prototyping, iterating, and testing mechanisms. One of our subsystem teams has also started building a final mechanism to go onto our competition robot. Going into second half of week 2, our team plans to continue testing and finalizing mechanisms in order to finalize the first rendition of our CAD.

Intake - Coming into week 2 of build season, the Intake team continued testing materials for the grippers and prototyping different mechanisms.

  • End Effector Group - Following the testing with a cut up 2020 Power Cell, the End Effector group found that a material with a rubber-like material that allows for better grip while still remaining compliant to the game pieces was optimal for the gripper. Going off these findings, our mentors bought some cleaning sponges and staircase tread strips. Using these materials, this team assembled the prototype shown below. During tests, we found that these materials led to a better grip on both the cube and cone. While these tests proved successful, the team decided to create another clamp-like gripper. The main reason for this is because this team believed there were simpler and more effective ways to create a gripper-like end effector. Our students were doing some research and brainstorming, and decided to prototype a claw-like grabber that uses pistons to actuate the forks. The End Effector team finished this prototype and started to do some tests. Their testing proved successful as this mechanism proved to have good enough grip strength and range of motion. Going into the second half of week 2, this group will work towards incorporating the end parts of fork. This will allow the team to test the gripping material and free-spinning aspect of the claw later this week.

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  • Out-Of-Bumper Group - The Out-Of-Bumper group started week 2 with a discussion to refocus the goals of the intake mechanism. During this discussion, the group defined what the intake mechanism needs to do in order to achieve the goals for the robot our team set at the beginning of this season. While discussing, the team took note of the goals relating to our robot’s movement capabilities. Our robot would need to be able to intake game pieces from more than one direction. With the previous few prototypes, this team realized that our robots efficiency and movement would have been inhibited as these prototypes only allowed intake of game pieces from one direction. Keeping this in mind for future prototypes, this group set out on researching intakes that would allow the robot to pick up game pieces while strafing. This led them to building a prototype inspired by NRG’s, team 948, “Interpretive Dance” intake prototype. The only significant difference ours incorporated that differed from NRG’s is we only used one screw to hold on the legs. Doing so allowed us to adjust the height of the rollers between tests. With the first rendition of this prototype built, the Out-Of-Bumper group set off for testing. As we previously posted, the first test of this system sent a cone into the ceiling. After slowing down the drills powering the mechanism, the group continued testing and made note of some important details. Following these tests, the team decided to build another iteration of this prototype to incorporate the ability to adjust different measurements. These measurements include height, widths, and size of the rollers. Heading into the second half of week 2, this team plans to continue testing with hopes to get some finalized measurements. Along with this, this teams plans to start brainstorming and researching ways to transition from this intake to the claw mechanism.

Handling - The Handling group spent most of the week building the Thrifty Bot kit elevator for our robot. On Monday, they cut all of the required tube, CNC-machined the brackets and gussets, and built the bearing units. On Tuesday, the Handling group assembled the kit elevator. To accomplish this, they riveted the parts together using brackets, screwed the bearing units onto the stages, cleared space for and installed the shaft bearings, and demonstrated the moving elevator to the team. After this, we mounted the motor that powers the elevator. Going into the second half of week 2, the Handling team will be finalizing the elevator and its mechanisms. Once that is completed, the team plans to continue prototyping the arm of the elevator and its counter-balancing aspect.

Charge Station/Chassis - Due to changing focuses during the first half of the week, the Charge Station did not make any significant progress in testing or prototyping. That said, this group plans on creating another prototype to attach to one of our practice chassis. This prototype will have similar functionality as the first prototype, but will be a smaller, more condensed version in order to simulate the actual size of the mechanism on our competition robot. Along with this, the Charge Station group plans to talk with our programming team in order to get some test code for the auto-balancing aspect of the drivetrain.

Programming - Up to now, the programming team has been focused on making the Swerve code work. During testing, the code proved successful and was working up until a student of ours may have put a hole in the wall. Other than getting the swerve code working, the Programmers have been split into multiple groups across each subsystem the past week and are working mostly independently on each of their subsystems. The programmers working on handling have created constructors and methods for both the elevator and arm. They are planning to start testing later this week. Charge station has been mostly focused on the use of vision over the past week and has decided to use PhotonVision. They have also decided the robot is going to have 1 or 2 cameras. They have decided that the robot should have a camera to face towards where we place game pieces, and a second camera facing out from our intake.

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So uhh… we’ve used these wheels for testing and had duct tape on them that was about 1/8th of an inch thick…

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touch and own the wall

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6421 - 1/22/22
Week 2 OA Update

Our team has spent the majority of week 2 continuing prototyping, iterating, and testing mechanisms. Unfortunately, some of the mechanisms have taken a bit longer than expected to finalize, so our team has not finished the first full CAD model of our robot. That said, our programming team has been able to make greater progress on the robot code. Going into week 3, the goal of finishing the first CAD model of our robot is going to roll over as our subsystem teams continue to test and finalize their mechanism.

Intake - Coming into week 2 of build season, the Intake team continued testing materials for the grippers and prototyping different mechanisms.

  • End Effector Group - For the second half of week 2, the End Effector group worked on finalizing the V1 gripper mechanism. After incorporating the free-spinning aspect and sponge material at the end of the claw, the group spent some time testing the V1 of the claw. The group found that the pistons would have to be relocated in order to increase compression force on the game pieces. As the group worked toward a gripper V2, they decided to CNC-machined Polycarp claws that were spaced out by multiple 1 1/2 inch spacers. This allowed for a lighter end effector and created space or a custom 3d printed mounting system for the free-spinning aspect at the end of each claw. The End Effector group did not have the time to start testing with the V2, so that is where they plan to start at the beginning of week 3.

  • Out-Of-Bumper Group - The Out-Of-Bumper group continued into the second half of week 2 by continuing the testing process with the previous prototype. After some more testing, the group used this prototype and attached it to a dolly to simulate the movements of a Swerve. Ensuring to keep proper heights and dimensions of the prototype, the group began more tests while moving the system to the game pieces, rather than moving the game pieces to the intake. Tests proved successful as the mechanism continued to work. Heading into week 3, the Out-Of-Bumper groups plans to create a final rendition of their out-of-bumper intake. Once this is complete and testing has been completed, look out for another OA update from us that goes more in-depth about this system.

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Handling - As the Handling group finalized the manufacturing of the Thrifty Kit elevator, the group passed it off to the programmers to work on. While the programmers worked on the elevator, the Handling group continue brainstorming and prototyping ways to create a passive way to counter-balance the arm. After some more testing, the group finalize how they are going to create their “weightless” arm and started to CAD the mechanism. Heading into week 3, the Handling group plans to finale their CAD model and start manufacturing the rest of the arm mechanism.

Charge Station/Chassis - The Charge Station group started week 2 by finishing prototype V1. Overall, their testing were successful, but the group found that the prototype was mis-sized in many ways. The group then started building a V2, which was similar to V1, but instead of having two belts attached to sliders, there was one chain. After some testing, the group had some difficulties with the chains, the sliders, and the pieces of 80/20. They worked toward fixing the problems but experienced more issues after testing again. The group fixed most of the errors but still needs to fix the chain. After doing so, they’ll be able to test the prototype to make sure it works well. After the testing is done, the group hopes to have it completed and sent off to the programmers by Monday.

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Programming - As mentioned before, the programmers have split themselves up among the different subsystems for the robot. This has allowed our programming team to make considerable progress in multiple different areas.

  • Vision - Some programmers have continued working on tuning our vision system. We chose to use the Limelight software instead of PhotonVision because it works better with the retroreflective tape, which we plan to use in addition to the AprilTags to line up for scoring. We are also planning to use the neural network functionality with the newest version of Limelight software to detect cubes and cones. We will continue setting up a second camera with the Limelight software next week.

  • Intake and Handling - Programming has created the intake-grabber branch and created two subsystems: one for the intake and one for the grabber. In both subsystems, simple double solenoid objects were created. Along with these, actuation and toggle methods were created for each of them. Additionally, motor objects were created in the intake subsystem, and a generic set speed method was created. Necessary constants were added to each respective constants subclass. Similar to Intake, Handling created two new branches for the elevator and arm branch. In each branch the programmers added one subsystem, one for the elevator in the elevator branch and one for the arm in the arm branch. Those two subsystems have been set up with constructors, basic methods, and constants. This week in particular the focus was on the elevator subsystem and moving our elevator to a position. It started with manual movement and eventually got it to move to a set position with the press of a button.

  • Swerve - The programmers have made significant progress towards a well-functioning swerve drive. The translational functionality of the swerve is complete and fluid in its motion. However, only parts of rotational functionality are working at this point, those being the ability to rotate in place and while moving with proper speed. The aspects that need more work are preventing the swerve from slowly rotating when drivers go forward and backward with no rotational input. Along with this, the PID tuning still hasn’t been completed and turn-to-angle buttons are only partially functional. There has also been significant debugging since last week such as removing restricted wheel rotation range (180 degree only, now full 360), removing wheel turning choppiness, proper rotation direction from each wheel, addition of ramping acceleration, deceleration through slew rates and PID (fixing control problems), fixing infinite rotations bug, fixing misalignment between CANcoder and turnMotor encoder, and fixing unit conversion methods. There were also some added features such as the choice of which driving control scheme someone wants to use (throttle by trigger or throttle by joystick) via a sendable chooser that can be changed while the robot is enabled. The Y, X, A, and B buttons on the Xbox controller have been programmed to turn the robot to 0, 90, 180, and 270 degrees respectively. That said, this feature is still experimental and only partially functional. All current bugs are planned to be fixed throughout the next week, and all currently mentioned features are planned to be fully operational before the end of next week.

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Our current, and best, rendition of our claw mechanism uses Cuisinart Quilted Silicone Potholders as a gripping material…

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To add to Wes’s post, the pot holders were available at Walmart. We tried many materials and both the cone and the cube stick to these the best. The gripper design is meant to allow the cone to free spin. One of the challenges is to make sure your shafts are aligned horizontally when pinching the cone. If the shafts are misaligned at an angle, the cone does not spin as freely. We did some clamp testing today and found that the top 3rd of the cone will compress to about 1 1/4" +/- 1/8" with 60 psi. So, we will be building to have our spinning shafts aligned at that distance on the clamping mechanism. This will give us the widest range of area to grip on the cone and ensure that the self righting will occur with no issue. We also have continued to make the clamping surfaces smaller and that also appears to help with the free spinning as well.

6421 - 1/27/22
Intake Mechanism Update

As mentioned in my previous weekly update, here is the Intake Mechanism Update. This update will include the details and relevant measurements of our final prototype, the CAD model and finalized measurements, and what are next steps are in manufacturing and testing.

The Prototype:

  • Background Leading up to the Final Prototype: Our team went through 2 different out-of-bumper intake systems before we started conceptualizing and prototyping the current prototype. We abandoned our previous 2 prototypes as they did not allow our robot to meet the goals our team set. Before diving into more research and brainstorming, out Intake team had a meeting to reevaluate what the out-of-bumper intake needs to be capable of doing. After looking back at our goals, the Intake group made made note that the intake needed to allow our Swerve drive to utilize its full mobility. Along with this, the intake needed to bring the cubes and cones into the robot in a predictable and repeatable way. With the refocused needs of the intake system, our team set out to brainstorming and researching different mechanisms. As the research continued, we came across NRG’s, team 948, “Interpretive Dance” intake prototype. Studying NRG’s mechanism, the Intake team observed the mechanism’s ability to bring in the cones base first regardless of cone orientation, and the team realized the plausibility to modify the mechanism to allow for multi-directional intaking of game pieces. So the team started to prototype.

  • The First Rendition: Our first rendition of this mechanism was a rough concept prototype.

    • Key details are as follows:

      • “Legs” attached at one point to allow for easy height adjustments.
      • 4 offset shafts of 4" compliance wheels as they offered better grip and compliance to both cone and cube.
      • 8" gap between wheels as a starting compression to test.
    • What we learned:

      • Spacers between wheels allowed for dead spaces where the cone was not being contacted; we found that solid rollers eliminated dead spaces and allowed for more contact area.
      • Heights of rollers were different due to offset shafts; we switched out a set of 4" rollers with 3" rollers to compensate for the offset.
  • The Second Rendition: Iteration of mechanism with implementation of what we learned from concept prototype.

    • Key details:

      • Studier built legs with 1/4" markings along the bottom for height changes.
      • Duct Tape on compliance wheels to simulate full roller of compliance wheels.
    • What we learned:

      • Height of rollers off the ground matters; we found that 6.75" off the ground allowed for good contact and consistent intake.
      • A severe lack of compression when cones came in at an angle; we did the measuring and found that a gap of 6" would eliminate most dead spots.
  • The Third Rendition: A slightly more optimized prototype to start to finalize measurements.

    • Key details:

      • System mounted on Dolly after finding proper height of rollers to simulate Swerve-like movements.
      • Bottom of rollers mounted at a height of 6.75"
      • Length from wheel-to-wheel reduced to 6" to increase compression.
    • What we learned:

      • While not severe, there still remained a lack of compression as cone did not always get picked up; we incremented the wheel-to-wheel length until we found that 5.5" was truly optimal for consistent pick up.
      • Inconsistency in the pick up of cones as they would sometimes get wrapped around one roller due to compressibility and gaps in the corners of the shafts.
      • Non-Duct Taped compliance wheels offered better grip on both the cone and cube.
  • The Final Rendition: The “most” optimized prototype used to gather final measurements for the CAD model.

    • Key details:

      • Utilizes Stealth wheels at the end of each roller to eliminate possibility of cones getting caught in corners of shafts.
      • Sets of 4" and 3" rollers to compensate for the offset in shaft heights.
      • Wheel-to-wheel length of 5.5" allowed for optimal pick up rates of both cubes and cones.
      • Wheel height off the ground set at 6.75" for optimal contact with game pieces.
      • Top roller vertically offset by 4.5" to “kick” the game pieces to a place where the claw would be able to grab it.

The CAD Model:


  • Changes made in CAD:

    • Shafts set on the same plane to reduce variability in testing outcomes possibly due to differing wheel sizes.
    • Shafts driven in combination of 2 Neo motors and bevel gears.
    • All roller are now 3" to condense overall mechanism size and weight.

Our Next Steps:
As of yesterday(1/26), the Intake team has already started machining different parts of the intake mechanism. Once the manufacturing of parts is complete, the group will build V1 of the out-of-bumper intake mechanism. As parts are being machined, the Intake group will, and already has, been brainstorming on how to complete the transition aspect of the intake. Looking at the full robot assembly on CAD, the game pieces do not need to go far past the main point of intake. Through manufacturing the first rendition of the intake mechanism, the intake team hopes to prototype and iterate different passive ways to catch or corral the game pieces to a position for the claw to grab. Another aspect of the intake that the team needs to figure out is the actuation of the mechanism. We believe the solution is a modified four-bar mechanism, but the Intake group needs to figure out how to mount to the robot or elevator.

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6421 - 2/1/22
Mid-Week 4 OA Update

@Wesley_6421 forgot his laptop in the room because we were using it to document wiring so I’ll be posting on his behalf this time :wink:

For most of week 3 and the first half of week 4, our team spent our time continuing to finalize prototypes, manufacture mechanisms, and we began testing the mechanisms. By the end of week 3, our subsystems had completed the first fully assembled CAD model of our robot. As of yesterday (1/31), our Mechanical team has fully assembled the first rendition of our robot with the exception of a few components. Once the Electrical team has fully wired the robot, it will be sent off the the Programming team to continue coding, tuning, and testing. For the rest of week 4, our team to plans to continue testing their subsystems with the goal of starting a V2 of the robot by the weekend.

  • End Effector Group - The End-Effector group continued to make improvements to the claw and continued testing different iterations to get it fully functional. To do this, the group first sketched and cut arms with proper geometry that could grab the cones and cubes without interference. After this, the group tested compression and grabbing points on the game pieces. As the End-Effector group was testing, they found that the length of the arms allowed for bending in the polycarb arms. This in turn created slip in the mechanism as it was grabbing game pieces. Later in the week, the group tested different ways to stop the bending. The group came up with the idea of using 3d printed pieces to fill in the gaps left between the two plates of each arm. These pieces are still in progress of being printed. Despite this, the End-Effector team mounted their mechanism onto the competition robot at the end of yesterdays meeting.

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  • Out-Of-Bumper Group - The Out-Of-Bumper group started last week by finalizing the CAD. Once this was done, the group began to fabricate the parts for the intake. Once all parts were fabricated for the intake, the group began the construction of the mechanism. The group riveted the mechanism together to insure a lighter-weight mechanism while still having the rigidity needed to for the bevel gears that are used. Despite the previous prototypes having offset shafts, the group decided to use inline shafts with bevel gears as this would allow for a lighter mechanism with efficient power transmission to the wheels. Once the intake mechanism was completed, the group needed to focus their efforts into the actuation of the mechanism. The team determined a four-bar system would be effective in the actuation of the mechanism. Outside of meeting hours, the group did research and the math necessary to determine the pivot points, the arm lengths, and the pistons needed to power the mechanism. Coming into yesterday’s meeting with their research, the team cut our the arms and mounted the mechanism onto the competition robot. Going forward into the second half of week 4, the Out-Of-Bumper team will be doing some troubleshooting as the game pieces are unable to be contacted due to height of the 2x1 frame.


  • Handling - By the end of week 3, the Handling team had completed the first rendition of the elevator and arm mechanism and mounted them onto the competition robot’s chassis. They have already passed their mechanism off to the Programming team to start working on the code. After sending their mechanism off to the Programming team, the Handling team refocused their efforts to assisting other subsystem’s in their work.

  • Charge Station/Chassis - After some testing, the Charge Station group realized that the prototypes for shifting weight had little to no effect on the Charge Station. During their tests, the Charge Station group observed that 30 pounds would effectively level the charge station if a single robot was close to centered, and the weight could extend outside of frame perimeter. Unable to determine if 30 pounds would have an effect with 2-3 robots, and their allowance of weight only being 30 pounds, the team decided that focusing on a way to balance on the Charge Station would not be beneficial for our team’s goals. After coming to this conclusion, the Charge Station group decided to refocus their efforts and help assist the Intake team with their mechanism. Going forward into the season, the Charge Station team will remain open to new ideas and may resume work if the team determines that a new design is necessary later in the season.

  • Swerve/Vision - After encountering some issues due to not inverting the gyro angle correctly, the programmers got their swerve code working on a practice bot that has the same dimensions as our competition robot. The Programming team also worked on tuning slew rates and motor deadbands. The programmers also continued setting up our Limelight cameras, but are currently working to resolve problems with accessing the camera feed after setting up a static IP address. Next week, the Programming team will continue setting up the angle offsets on our competition robot so they can begin tuning drive code for this robot.

  • Subsystems - Due to some complication with the Swerve, the coding on the subsystems was temporarily postponed. Despite the heavy focus on the Swerve, the Programming team still made progress with the subsystems’ code. In the arm subsystem, the Programmers made several test methods, as well as methods that would likely be included in the final arm code. These include methods for variable feed forward, one of which calculates feed forward as a proportion of the maximum. The Programmers have also done testing and calculations to determine what angles and elevator heights would be ideal for placing game pieces at each node.

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OA Tangent - The Rogue Falcon

I don’t want to throw proverbial gasoline on a certain dumpster fire, I think it’s important to discuss a scary incident that happened on our practice robot Polly due to a faulty falcon.

The Catalyst

We were running our practice swerve around for driver trials last weekend when one of our drive motors started stalling, the shaft was wiggling, and upon further inspection one of our drive falcons had sheared all its bolts and the bolt bits had fallen into the spinning part of the motor, effectively killing it. We’re looking into how to better protect our remaining falcons from a similar fate, but this was just the start of the issues.


RIP Falcon # 1

The Oopsie

The motor was replaced with a spare found in the workroom. What we had forgotten at the time was that this motor had been tripping its 40A breaker a few months ago and was removed. Back when that issue was originally detected, it wasn’t causing major issues, simply swapped it out and we were A-ok.

Then we booted up the robot and noticed the replacement falcons wires had twitched, shortly followed by the robot shutting off and rebooting.

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See the wire twitch? Yeah that’s definitely not good,

What I realized a bit later was this motor wasn’t tripping its 40A breaker in the PDP, it was tripping the main breaker of the entire robot, likely drawing ~200A in the process, yikes. My best guess as of now is that the motor has some form of an internal short which effectively resulted in us shorting out the whole bot

The Aftermath

After this incident (and unplugging the offending motor), the PDP was reporting hardware failures and our entire CAN bus was freaking out. We ended up replacing the PDP with a fresh one and a new main breaker as well just to be safe.


Poor PDP definitely took one for the team

Overall I think we got pretty lucky, Polly was driving around today. Not sure we’re completely out of the woods on hardware damage done to that bot, but as we finally had to rip the last falcons out of our 2022 bot Goose, I hope our remaining motors hang on tight for the long season ahead.


All good bots must come to an end

Moral of the story: Even if a component is in short supply throw it out to avoid more serious and scary issues!

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Hi! Team 5785 here! Would you mind sharing what durometer your compliance wheels are?
Thank you!

For our intake, we have 35 durometer wheels from AndyMark for the inside wheels. We just got some red colored ones that match our team colors. The outer wheels are stealth wheels. We were finding during testing that the cubes would get sucked into the corners and get pinched with the compliant wheels. (Sharp make cube sad). We changed to harder stealth wheels and have not had any issues since the change.