Full Frame

Set the stakes. The drivetrain is the foundation — intake, elevator, shooter all reference it. If the frame is crooked in CAD, every mounting hole downstream is wrong. Tell them a real FRC frame is usually 2x1 aluminum tube with swerve in the corners, sized to fit inside the 120in perimeter rule with bumpers. Today they assemble it, not design the tubes from scratch.

This is the #1 beginner confusion coming from Onshape's Part Studio. In Fusion, bodies don't joint to each other — components do. Demo: select a loose tube body, right-click, Create Components from Bodies, then rename it. Stress good naming NOW — you'll be picking these from a list 30 times. Activate a component (double-click) to edit inside it; click the top node to get back out.

Bring in the tubes for the four sides of the frame. Don't obsess over exact placement yet — that's what joints are for. Pick ONE tube and Ground it (right-click > Ground) so the whole assembly has a fixed anchor; otherwise everything floats and drags around. Common mistake: grounding nothing, then the whole frame slides when you grab a part. Mention real FRC frames often use 2x1 for the long rails and clever gusset corners.

Joints are Fusion's version of Onshape Mates. Demo the workflow slowly: hit J, hover until the snap point you want lights up (face center vs edge midpoint matters a lot), click part 1, click part 2, choose Rigid. Rigid = zero degrees of freedom, perfect for a welded/bolted frame corner. Watch for: picking the wrong snap point and getting the tube flipped 90 degrees — use the Flip and offset options in the joint dialog to fix without restarting.

Insert > Insert McMaster-Carr or drag in a downloaded STEP/F3D of a REV or WCP gusset. Snap the joint to a HOLE CENTER, not a face corner — this auto-aligns the bolt pattern. Real talk: gussets are what make a tube frame actually rigid; a bolted frame without gussets racks like a parallelogram. If their gusset lands inside the tube or floating, check they snapped to the correct hole and used the offset field.

Insert the real module (REV MAXSwerve or SDS MK4i) from a downloaded STEP — don't model it. Treat the module as ONE component and rigid-joint just its mounting plate; you do NOT joint the steering internals (that's the module's own job). Common mistake: modules placed with wheels at different heights or rotated inconsistently. Eyeball that all four pods sit at the same Z and the bellypan face is flush. Note real bolt pattern is usually a square hole grid on the frame corner.

Teach Rigid Group as the efficiency tool. Jointing 40 bolts individually is misery — instead, position them, select all, and right-click Rigid Group to lock them to the frame in one move. Difference to hammer home: a Joint mates two components with a relationship; a Rigid Group freezes a whole SET together with no DOF. Use McMaster-Carr insert for real 10-32 socket head cap screws. Don't over-detail threads — it kills performance.

This is Fusion's answer to Onshape Variables. Modify > Change Parameters > add User Parameter. Tie your tube length and joint offsets to frameWidth/frameLength so resizing the frame is one edit. FRC tie-in: frame size is a strategic choice constrained by the 120in perimeter and bumper rules — being able to test 26in vs 28in vs 30in fast is huge. Mistake to flag: hardcoding numbers everywhere, then having to hand-edit 12 places when strategy changes the size.