Electronics Layout

Open by busting the myth that electronics are 'figured out later.' Every veteran team has lost a match to a wire that fell off or a CAN bus that came loose because the board was crammed. Tell them: the electronics board is a real subsystem with real constraints — accessibility, heat, wire length, vibration. We CAD it so we can pre-drill mounting holes and route wires deliberately. Common rookie mistake: leaving 2 inches of clearance for a connector that needs 5.

Walk through the real parts you'll actually mount this season. Kraken X60s have integrated Talon FX controllers, so you mount fewer separate controllers than a NEO/SPARK MAX setup. Clarify PDH (REV, modern) vs PDP (CTRE, legacy) — most teams now run PDH. Emphasize the radio (VH-109 this year) and that it MUST be reachable to re-image. Point out the main breaker has to be hittable by a referee/driver in an emergency.

In Fusion, vendor STEP files get uploaded to your Data Panel, then inserted into the assembly — this is our equivalent of Onshape's MKCad library. REV and CTRE publish accurate STEP models; download the real ones rather than modeling boxes, because connector clearances matter. Show them how inserting creates a component. Stress renaming immediately — an assembly of 'Component12, Component13' is unusable. Ground the plate first so nothing floats.

Start the actual modeling here. The plate is usually 1/8in to 3/16in polycarbonate (lexan) — light, non-conductive, easy to drill. Show Modify > Change Parameters to make a user parameter like 'plate_thk = 0.125 in' so they can swap thickness globally later. Polycarb is chosen over aluminum specifically because it won't short electronics if a wire chafes. Mention they should leave a border margin so mounting bolts to the frame don't collide with components.

Layout strategy: place the power-hungry PDH near where the battery sits so the heavy-gauge leads stay short (less voltage drop). Use rigid Joints, not Mates — in Fusion the equivalent of an Onshape Fasten mate is a Rigid Joint. Demo capturing the position then applying As-Built Rigid Joint. The 'finger-width gap' rule prevents the classic mistake of a board so tight you can't plug in a CAN wire or hit a breaker.

If running NEOs, you'll have a SPARK MAX per motor — these get warm, so don't bury their vents. Krakens save board space because the controller is integrated. Teach them to orient connectors all the same direction so the wiring harness flows cleanly. Mirroring matters: if drivetrain has 4 controllers, lay them symmetrically so wiring is intuitive for the build team. Use Fusion's Mirror feature on positioned components if helpful, or just copy-paste.

You won't model every wire as a 3D body, but sketching the runs as lines reveals whether a path is too short or crosses itself. CAN bus is a daisy-chain — plan the order of devices so the loop is short and tidy, terminated at both ends. Keep fat power leads away from signal/CAN to reduce noise and for neatness. Connectors need bend-radius room — Anderson/SB50 and Phoenix connectors are bulky. Mark holes for zip-tie anchors now so they get drilled.

Now make the plate manufacturable. Use the Project/Include geometry tool to pull each component's mounting-hole locations onto the plate sketch, then place real holes. Most FRC electronics mount with #10-32 or #8-32 hardware, often on standoffs. Show the Hole feature vs a simple extrude-cut circle. Don't forget the holes that fasten the plate itself to the robot frame. This pre-drilled plate is the payoff — hand it to a router or drill press and everything lines up.

Run Inspect > Interference to catch overlapping components — a common error after dragging parts in. Remind them clearance isn't just static overlap; a connector needs swept room to plug in. Assign the polycarb material so Fusion computes realistic mass for the robot weight budget (you're chasing the 125 lb / ~115 lb limits). Do one last human-factors pass: pretend you're the pit crew and 'reach' every serviceable item.