Scrambler

Overview

Scrambler devices transport an egg to a target quickly and accurately without breakage. Performance hinges on controllable acceleration, precise braking, and straight‑line alignment.

Motion modeling

• Kinematics: stopping distance depends on pre‑brake speed and brake deceleration; reduce speed variance to stabilize stop distance.
• Energy budget: gravitational/elastic energy → translational + losses (rolling resistance, aerodynamic drag negligible at low speeds). Consistency beats peak speed.

Braking systems

• Friction brakes: pads on wheels/drums; sensitive to surface and wear; adjustability is key.
• Mechanical stops: string wraps, cams, screw stops; robust but require careful calibration.
• Ramps/wedges: convert forward motion into lifting work; more tolerant to small speed changes; ensure repeatable geometry.

Alignment and chassis

• Wheel alignment: toe and camber near zero; matched diameters; stiff chassis to prevent torsion under load.
• Mass distribution: lower CG to prevent tipping during braking; symmetric layout reduces yaw bias.
• Guidance: rails vs free‑running; if free, use longer wheelbase and track width for stability.

Calibration

• Distance tables: command vs measured distance across temperatures/surfaces; interpolate near target; bracket target distances.
• Pre‑run checks: wheel cleanliness, brake reset, starting position and angle; battery/rubber condition if applicable.

Worked micro‑examples

1. Brake linearization

• If friction brake decel varies with speed, pre‑slow before brake engage using a mild drag to reduce variance at the final brake.

2. Wheel mismatch

• 1% diameter difference across wheels causes curved path; compensate with slight toe or by matching wheels within tighter tolerance.

3. Ramp stop sensitivity

• Raising ramp angle slightly increases vertical work; tune to widen the tolerance band for final stop distance stability.

Pitfalls

• Over‑optimized for speed with fragile braking repeatability.
• Calibrating on one surface only; ignoring temperature/humidity effects.
• Sloppy starting alignment; inconsistent release forces.

Practice prompts

• Compare the repeatability of a friction brake vs ramp stop using 10 trials each and analyze variance.
• Design a toe measurement method with simple tools and specify acceptable tolerances.
• Build a distance interpolation method from a calibration table and validate against new targets.

References

• SciOly Wiki – Scrambler: https://scioly.org/wiki/index.php/Scrambler