What this event is about
Build a roller-coaster apparatus (often for a vehicle or ball) scored on time, height changes, and successful runs.
Study plan
Setup (team of up to 2, ~12 min / 8-min setup+runs, Eye Protection B, Impound Yes; track + ≥1 ball/sphere ≥1 cm, visible always)
- Size budget: device (ex-ball) ≤30.0 cm W × 80.0 cm L × 60.0 cm H. Size Score = (60−H)+(30−W)+(80−L) in 0.1 cm — smaller footprint scores more.
- Energy: gravity only from ready-to-run (except Elevator simple machines); no magnets/electrical/electronics; no springs/rubber propulsion. Pencil start: ES #2 pencil held only in hand releases ball at Start Line.
- Exactly one labeled Start and Finish line (perpendicular to travel); relative positions fixed after impound; safe stop after Finish.
- Elevators (optional, 50 pts each type once): Type 1 first-class lever + wheel & axle IMA<1 lifts ≥10 cm; Type 2 second-class lever + pulley IMA<1 lifts ≥10 cm. Label types; counterweights OK.
- Loop (optional): one continuously concave self-intersecting Loop; label POI and height; track not fully enclosed; ball stays in contact; unsupported from below at top. Loop Score = 3 pts × whole cm of height POI→highest inside point.
- Target Time revealed at setup: 30–60 s (5 s Regionals; 2 s State; 1 s Nationals). Time Bonus = 5 pts/full second up to TT; Penalty = 5 pts/full second past TT up to 2×TT. Practice adjustable delay features.
- Competition: practice runs free in 8 min; declare scorable runs; don’t touch during scorable run; height measured after each scorable run. Run Score = Size + Time + Elevator + Loop; better of 2 runs counts.
- Failure modes: Time Score 0 if Finish not crossed (still can earn Height/successful Elevator/Loop before stop). Tiers: 1 clean, 2 any violation, 3 not impounded. Iterate track length vs reliability; photograph setups.
Tips
Friction and alignment lose more points than “not enough hills.”