8738 SLICE - 2023 Open Alliance Build Thread

Welcome to SLICE 8738’s first ever build thread. We’re so excited to be a part of the Open Alliance for the 2023 season.

Who is SLICE

SLICE Team 8738 is a second year team based in Fuquay-Varina, NC. We currently have 52 students registered for the upcoming season. We meet every weekday from 2:30-3:30, running later as needed during the season.

Our mission is to Serve our community by inspiring students at our school to be science, technology and business Leaders and Innovators. With essential help from our local Community, we strive to develop well-rounded life capabilities including self-confidence, professionalism and pursuit of Excellence.

It’s all in our name — SLICE.

Our Team:

Rapid React Recap

For our rookie year, we decided to go all out and attempt an upper hub robot with traversal capability. Due to shipping delays and minimal offseason prep however, we struggled with reliability issues throughout the season. That is something we plan to improve on for the upcoming season.

Even with our numerous robot issues, we still managed to achieve the following during the season:

  • ECU Rookie All Star Award
  • Guilford Rookie Inspiration Award
  • District Rookie All Star Award
  • Competed in CMPTX Carver Division
  • Carver Division Safety All Star
  • Offseason Doyenne Inspiration Spirit Award

Our 2022 robot:

Charged Up Goals

For the upcoming season, we have identified the following key design principles to design our robot around: Reliability, Durability/Repairability, and Efficiency. We aspire to return to Worlds in the upcoming season.

Open Alliance Targets

We aim to post updates at least once a week, in addition to structured recaps at the end of each week. We will make our CAD publicly accessible and aim to release updated code every 1-2 weeks.


Website: fvhsrobotics.com

Youtube channel: youtube.com/@user-od9mn3ld8k

Linktree: linktr.ee/fvhsslice

Blue Alliance: thebluealliance.com/team/8738

Github: github.com/SLICE-8738/RapidReactOffseasonCodeRelease

Robot CAD (Unfinished): cad.onshape.com/documents/025c7f8286f7bc12b9a5687f


Small question about the design of your 2022 robot: I see for that for the indexer you use vectored wheels on 1/2in shaft to elevate the balls. Was this reliable? Was there any tweaking you needed to do? Seems pretty clever to me, just curious about how it worked in practice.

Our indexer worked alright for most of the season. However, we had to redesign the funnel (the part of the indexer that guided the cargo) several times. The biggest issue we encountered regularly was that sometimes the indexer would sometimes lose traction on the cargo halfway through. When that happened, we had to briefly reverse the indexer and run it through again, and it would usually work then.


Slice Week in Review: Week of December 12, 2022

In Short: This week our team continued work on our offseason contest/challenge, we worked on fixing our 3D printers, and we also began reorganizing our closet and build space while programming did various testing with autonomous mode.

Most of our 3d Printers

Shrethan Showdown: Our team was split in half to compete in an in-house competition called Shrethan Showdown (Named after our co-founders), where the task is to build a fully adjustable marshmallow cannon to be mounted on our drivetrain. This week, teams continued designing, 3d printing, and assembling parts for their cannon to compete shortly before kickoff.

Team Shrey working on their Marshmallow cannon for Shrethan Showdown

3d Printers: Our team has experienced various issues with all of our printers, and continues to have little success in creating a long-term fix.

Our Ender 3, nicknamed “Tony”, under repair

Outreach: A portion of our team volunteered to help with landscaping in a local neighborhood this Friday.

Our electrical captain pulling up bushes

Programming: The programming team recently regained access to the drivetrain after post-offseason deconstruction for autonomous testing. We are in the final stages of debugging Pathweaver autonomous, and have spent some time exploring the idea of tracking game pieces using Limelight.

Experimenting with Limelight cargo detection

Auto Testing Clip
Testing pathweaver autonomous

Electrical: The participants in our Electrical Apprenticeship continue to learn the essentials of electrical engineering, including the numerous types of tools and their applications.

Mechanical: Reorganizing the team closet and build space to improve efficiency and effectiveness for the upcoming build season.

Social Media: SLICE now has a TikTok! You can find us @Slice_Robotics!


Slice Week in Review: Week of January 3rd, 2022

This week, we finished preparing for kickoff, made progress on Shrethan Showdown (to be resumed after the season ends). All 3 of our filament 3D printers are now fully operational. Our electrical team continued working on their apprenticeship, the business team arranged a fundraising event at a local restaurant, and our programming team made sure our 2022 drivetrain code is as tuned as possible for the 2023 season.

Final Code Release: GitHub - flightpath24/RapidReactOffseasonCodeRelease


Slice Kickoff Week Recap

Kickoff Summary: We started the Charged Up season watching kickoff with 3459 Pyrotech. While we were there, we analyzed the rules and attempted a human version of the game to get a feel for it. In the days since, our design team has been preparing a set of goals in the form of a “Must have, Should have, Could have” document to compare potential ideas against. We have been asked to submit any designs we think of so that the design team has plenty of ideas to work with.

Regarding other subteams:

  • Electrical continues to run their apprenticeship
  • Programming is updating their devices and the RoboRIO to 2023 software
  • Business arranged a fundraiser at a local restaurant
  • Mechanical is preparing to build field elements and our new drivetrain.


Strategic Evaluation for Robot Design: EDP Design Proposal Rubric

Copy of our ideas slideshow: Slice Charged Up Ideas (Updated 1/13/23)


Charged Up Human Edition with Pyrotech

Day 1 Strategy Whiteboard

We also did some modeling to get a feel for the scale of the field compared to a typical drivetrain, and we believe that standard Kit of Parts sizes and other large robots may not be able to do a side-by-side triple charge station engagement outside of ideal circumstances, we are taking this into consideration for the design of our robot.


How did this exercise inform your robot design choices?

Edit: the docs are exceptionally well put together too. Very much worth clicking on.

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Agreed with James - lots of great prototype ideas captured!

Our mentors want us to create some physical prototypes before making any decisions regarding the robot design. I’ll make sure I answer this in a future post once we get there.

Slice Week 2 Recap


This week we began prototyping intakes and arms, started building a Charge Station and drivetrain, and began 2023 Robot Code.

Robot Design:

  • We are looking into a Rack and Pinion based telescoping arm after having many issues with string based designs in 2022
  • We purchased a Single Stage Thrifty Bot Elevator Kit
  • We are constructing a 20” x 32” KoP drivetrain to test the viability of narrow drivetrains (they aren’t cutting the end pieces yet so we can always go wider)

By Subteam:

  • Electrical is still progressing on their apprenticeship
  • Programming is working on implementing pathplanner (they started over after several months of debugging one issue after another), they are also researching Apriltags and Photon Vision
  • Mechanical was very busy this week:
    • The Prototyping branch started working on intake prototypes
    • The Field Construction branch started building the Charge Station
    • Some of our Seniors also started building the Drivetrain

Intake Prototyping

Drivetrain Construction

Perpendicular Elevator Concept Animation
One of many possibilities we are looking into for our robot


We are also looking into a rack and pinion arm. Let me know if you have any questions about it, but if you havent i suggest getting the 20 degree pressure racks from mcmaster, as we have found those mesh with standard cots gears pretty easily.

Thank you for the suggestion, I’ll pass this on to our mechanical team

We’re designing a rack and pinion arm that uses a hole pattern as the “rack” and interfaces with a sprocket “pinion”. We’ll see if this works and definitely update y’all. It’s something stryke force used to do a lot, iirc, and seems to offer a lot of simplicity and weight benefits.


Slice Week 3 Recap


In the past week, we built our field elements, determined our drivetrain dimensions, tested various code with our 2022 drivetrain, continued robot design discussion, and worked on early prototyping.

Subteam breakdown:

  • The electrical team worked on an ESD Detector, along with beginning plans for the E-board.
  • The mechanical team continued construction of the charge station, built a grid segment, and began building an elevator.
  • The programming team tested charge station auto balancing code, experimented with Apriltags using our Limelight 2+, and tested a quick turn button to turn the robot 180 degrees.

Our custom grid segment

A 3d printed segment of a rack and pinion arm

The charge station under construction

A prototype ESD Detector

First attempt at automatic Charge Station balancing

Successful auto Charge Station balancing


Slice Week 4 Recap:

This week, we continued building our drivetrain and elevator, re-analyzed our robot targets, timed crossing the field with our 2022 drivetrain, and designed our robot using blender (CAD soon?).

Subteam Breakdown:

  • The electrical team determined the placement of the E-board, drafted a layout and researched possible E-board materials.
  • The mechanical team progressed on drivetrain construction, continued work on the elevator, and reorganized the closet.
  • Basic elevator code is made, auto code is approaching the testing phase, and we decided to make our full GitHub repository public.


Drilling holes for our elevator

Blender models of our robot design


I’m curious, how do you guys plan to pass off the cube or cone from the intake to your elevator on your model?

From the looks of the blender model, the elevator has the intake attached to it via an arm with a wrist joint. So there isnt a handover necessary as the whole assembly is connected.

Slice Week 5 Recap:

Last week, we finished our drivetrain and are making good progress on our elevator. Our robot is mostly designed, with CAD being underway. We have begun testing our new auto code, held some driver training, and begun planning our E-box layout. Construction on other aspects of the robot will commence once parts arrive.

Our Kit of Parts Drivetrain

Design Review with our design team and mentors

Early auto testing

Very confused auto code

Elevator Progress

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I did not expect to see my team here (2022 robot pic at the top) best of luck to you all!!!


Do you guys plan on powder coating again this year? Last year it looked really good.