Crayola CAD, I call it Cartoon CAD, is incredibly effective and important. To me, CAD throughout the season never stops, we are constantly iterating the design which means we never stop doing CAD.
(Durations) below are estimates and often many of these steps happen in parallel. The drivebase is done first and quickly (<1 week) while other subsystems are in concepting phase.
Overall CAD steps:
- Whiteboarding, robot concepting (1 afternoon)
- This includes researching other robots or mechanisms used for similar tasks in past games
- Robot Architecture Sketches (2 days)
- Most often a Side View, illustrates the frame, bumper, intake, superstructure, and different scoring positions
- Often a separate sketch done by someone else for the endgame mechanism they are exploring in parallel
- Example from 2019 with intake, climber, arm on elevator, etc
- 3D Cartoon (Crayola) CAD (2-5 days)
- Extrude shapes to make a multi-body master model that has the Drivebase, Bumpers, Superstructure, Intake, Endgame mechanisms
- Sometimes separate those bodies into individual parts and remerge into an assembly so you can show the intake stowing, scoring positions, turret swept area etc.
- As the designed, I often find this takes me about an hour to split all this out, and honestly isn’t necessary for myself who can understand my own sketches, but is immensely useful for other team members to visualize the architecture, potential interferences, get excited about owning a certain subsystem, etc.
- Examples below from 2022 and 2023
- Prototype Subsystem Design (2 weeks)
- Always intakes and shooters, often feeders/serializers, sometimes drivebase if terrain on field
- Lasercut plywood, planetary motors or Falcon (more powerful than a handheld drill), adjustability like moveable roller position / compression amounts
- Lots of testing of different materials for optimal grippiness, etc
- Examples in 2020 Technical Presentation on prototyping serializers
- Initial Subsystem Design (1 week)
- Usually start a fresh Master Sketch that outlines the subsystem: motor placement, stroke length / range of motion, compression amounts / roller size, belt/gear powertrains
- Often these are multiple sketches stacked ontop of each other illustrating structure, powertrain, stow pose, top view, etc.
- I gave a meh workshop on Master Modeling that discusses some of these, especially the multi-body methods used more for robot architecture.
- Sometimes import Master Sketch into individual parts or just model parts as standalone pieces
- Start integrating subsystem together into a TLA (top level assembly) to ensure no collisions and lock in mounting provisions and other space claims on the drivebase that is being manufactured at this time
- Example, 2020 drive gearbox with layout sketch
- Detailed Subsystem Design (2 weeks)
- Add all the holes, screws, electronics mounting, bits and bobs
- Proper filenames with Cheesy Parts numbers
- Part drawings for manually machined parts
- Part dxfs / stls for CNC router / 3D printer
- Student subsystem owner is owner of procurement and kitting of parts for their subsystem, they see it through to completion
- Subsystem Iteration (5 weeks)
- Ongoing throughout the season, redesigning subsystems or tweaking as we see flaws, get inspired by other teams, have a new project for worlds, etc
- Much easier to do now with no bag