FRC 2713 - Red Hawk Robotics - 2023 Build Thread

FIRST Open Alliance
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General Requirements Regarding Pit + Shop Improvements:

After finishing our competition season, we realized that, in order to actualize our robot-centric goals, we must also make pit and shop improvements. With this in mind, we outlined a few requirements:

  • Moveable Pit: Not only from truck-to-venue-to-truck, but also easily moved during DCMP/CMP playoffs.
    • Additional benefit if NE FIRST keeps CMP pit + robot “shipping service.”
  • Integrated Pit + Shop: Team members becoming accustomed to working out of the pit during the season will improve efficiency during competition.
    • Removes need to pack and unpack prior to, and post competition, respectively.
    • Lower risk of “forgetting to pack” any items; can prove detrimental with non-COTS items.
  • Better Organized Small Parts + Tool Storage: To optimize pit space, we decided on using two carts: a COTS tool cart (linked here), and a custom and/or small parts storage cart (widely influenced by this video), which will be the focus of this post.
    • Prioritizing single-sided storage containers over double-sided storage containers.
    • Custom cart gives freedom of choice with regard to which storage containers we use (w/ the additional understanding that the game, and with it the parts we use, will continue to change every year).
    • Storage that’s user friendly; NOT:
      • Bins stacked directly on top of each other.
      • Boxes inside of boxes, inside of boxes (or, in our case, FIRST-provided totes).
      • Reliance on event-provided tables.
      • Tabletop workspaces becoming a method of storage; i.e. they are not available as workspaces.

Custom Cart:

The discussion soon split between two options: a separate Custom Cart and Battery Cart, and a Custom Cart with batteries. Although we have seen teams integrate battery storage into COTS carts, we felt this could be a safety hazard, i.e. highschool students pushing a 750 lbs cart up a ramp.

We chose this Harbor Freight (HF) bin for storing small parts. It contains variably sized inner containers, and is cheaper and more widely available than other alternatives. Since the HF bins aren’t deep enough to hold larger parts (such as COTS swerve module parts…), we decided to include different sizes of sterilite bin in the Custom Cart (links: 6 qt, 15 qt, 27 qt) (thanks to 2363 for the recommendations). We chose to not use the 27 qt sterilite bins because we felt they were not as space efficient as the 6 qt and 15 qt bins.

We then designed 6 layout variations for the cart in CAD (see v.4 for final version).

Layouts with Integrated Battery & Charger Storage

HF Bins + 6 qt Sterilite Bins

HF Bins + 15 qt Sterilite Bins

HF Bins + 6 qt / 15 qt Sterilite Bins

Layouts without Integrated Battery Storage & Chargers

HF Bins + 6 qt Sterilite Bins

HF Bins + 15 qt Sterilite Bins

HF Bins + 6 qt / 15 qt Sterilite Bins

Final Design with Removable & Standardized Battery Bays:

HF Bins + 6 qt / 15 qt Sterilite Bins:

HF, 6 qt, + 15 qt sterilite bins: (FINAL DESIGN); 2x1 Aluminum L Bracket Shelves


Front view, “pit/shop mode”

Other Perspectives

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Isometric view, “transport mode”

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Back view, “pit/shop mode”

To maximize storage efficiency and the longevity of the cart, we chose the version with batteries, HF bins, 6 qt, and 15 qt Sterilite bins. We used this design as a base, keeping small parts storage the same, and changing battery storage. We made several changes to the cart’s design – notably, standardizing not only the Battery Bays (i.e. all removable, all the same size, etc) but also the shelves for the 6 qt sterilite bins (see above). We removed the right-most Battery Bay design; the design became simpler and we only substituted a 15 qt sterilite bin for a 6 qt bin. The design’s specifications are as follows:

We prioritized the Battery Bays being removable. This ensures easier transportation to non-competition events (i.e., bringing batteries to drive practice, a demo, etc.) as well as simplifying the overall structure – the CAD model and the actual building process – of the cart. There are two versions of the cart with removable Battery Bays; we chose the second version (see above) because of its simplicity. We used dado joints to help further stabilize the cart, especially since it was horizontally divided by a single piece of plywood. Instead of wooden shelves, we chose to use 2x1 (x18”) aluminum L brackets provided by our sheet-metal sponsor, Churchill Corp. This change will simplify the design and allow us to fit more storage containers. We allocated space behind the Battery Bays for a power strip, and used this mounted outlet to easily connect the power strip to external power at competition and in our lab, and avoid dealing with a cable going through external panels.

Building the Cart:

After finalizing the cart’s design in CAD, we began the process of manufacturing it. We are extremely grateful to Boulter Plywood, a local plywood supplier, for providing us with high-quality Baltic Birch plywood at a discounted price. Additionally, we’re grateful to our school’s tech-ed teacher for lending both his expertise and his classroom’s woodworking shop to this project. We used a table saw to cut individual pieces of plywood, and started routing the smaller dado joints, using this Harbor Freight router. All dados are ¼” deep and ¾” wide. We made and re-used the same router jig (pictures below) for all smaller pieces, adjusting the dimensions accordingly. Larger dados — or those on larger pieces (i.e., the top of the cart) — were cut using a mentor’s table saw with a dado-blade. On the sides of the Battery Bay, we drilled two circular holes, using a Jigsaw to connect them to create handles.

Pictures

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Router jig for dado joints


Transporting plywood from the tech-ed shop to our shop

We then began constructing both the Battery Bays and cart without wood-glue, as a test fit. The Battery Bays are all completely “screwed-and-glued,” but we want to test the functionality of the cart before disassembling and glue-ing. We installed all of the shelves in-place, using different small jigs for spacing. We plan to continue working on the cart during build-season — hopefully ready for use by our first District Event, SE Mass in Week 1. We will update the thread with pictures and progress.

Pictures

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