Finishing The Frame

Set the stakes. On 7558, the person who CADs a frame is rarely the person who machines it. A messy model with bodies named 'Body1, Body2' and overlapping tubes wastes hours and burns aluminum. Today we turn a functional assembly into a professional deliverable. This mirrors frcdesign's 'Finishing the Frame' — same four ideas, Fusion tools.

Demo live: Inspect > Interference, window-select the whole frame, hit Compute. If two 2x1 tubes overlap at a corner, Fusion shows the shared volume. Common 7558 mistake: gussets modeled into the tube instead of butted against it, or a tube extended 1in too far at a miter. Leave 'Include Coincident Faces' off — touching faces (like a bolted joint) are intentional and would flood the list with false positives.

Walk through editing the timeline feature that caused the overlap — double-click it, change the distance or sketch dimension, OK. Stress the loop: fix one, re-check. Tip: a tiny 0.001in overlap still flags; that usually means a parameter mismatch, not real geometry. This is exactly why we use User Parameters later — one number drives many tubes.

Open the browser and rename together. Convention matters: pick a scheme and stick to it — by location (Front/Rear/Left/Right Rail) is best for a drivetrain frame. Bad names are the #1 reason a teammate can't pick up your file. Show drag-to-reorder and the collapse arrows so the tree stays readable. Mention: renaming a component here is what shows up on the BOM and drawings later.

Grounding the frame base keeps everything from floating when you drag. On 7558 frames most joints are Rigid (welded/bolted tubes don't move); revolute/slider come later for mechanisms. If anyone moved a part to peek inside, remind them to do Capture Position or Revert so the saved state is correct. A clean Joints folder with named joints is part of 'finished.'

This is the frcdesign 'Variables' concept — in Fusion it's User Parameters via Modify > Change Parameters. Create frameLength, frameWidth, tubeWidth(2in), tubeHeight(1in). Then in a sketch dimension type 'frameLength' instead of a raw number. Demo the payoff: change frameLength from 28 to 30in, OK, and watch every tube and the belly pan update. This is the single most powerful habit in CAD — set it up once, resize forever.

Press A for the Appearance browser. Drag materials onto components: brushed aluminum for 6061 tubes, a darker steel for #25 chain sprockets and bolts, maybe a team color on the belly pan. This isn't just pretty — correct appearances communicate material and read instantly in a design review. Caution: appearance is visual only; for real mass use Modify > Physical Material so your weight estimate is honest.

Final hygiene pass. Scrub the timeline marker left-to-right and watch for yellow/red error badges — fix any before saving. Group related features and give them names. Make sure the marker is at the end so the model is fully computed. Delete leftover construction sketches that aren't referenced. Then Save with a meaningful version name — version comments in Fusion are your paper trail, like git commits.