Soapbox Cart Honor

Recreational Activities

Requirements

1. Create a project to build a soapbox cart (bearing cart) within the following dimensions:
   • Length: 80 to 100 cm
   • Width: 25 to 35 cm
   • Thickness: 2 to 3 cm
   • Bearings with dimensions from 6203 to 6307

   Answer: Platform of marine plywood or solid wood (90x30x2.5cm), front and rear axles of metal bar (12mm), spherical bearings 6203 (17mm bore) or 6307 (35mm bore), front axle with a central pivot for steering, side brake. — 6203 bearings are smaller (17mm bore, 40mm outer); 6307 are larger (35mm/80mm). The larger they are, the more resistance but less rolling. Marine plywood resists moisture. The pivoting front axle uses a central bolt with a castle nut. Always design with seatbelts.

2. Know how to handle tools such as a hammer, saw, and drill, and know the necessary precautions when using each of them.

   Answer: Hammer: hold it by the end of the handle, the nail firm in the other hand, no fingers in the strike zone. Saw: fix the piece with a clamp, teeth facing forward, start the cut with a notch made by a knife. Drill: safety goggles, the bit centered, the piece secured, low speed on metal. — Essential PPE: goggles against splinters, gloves (not on the drill — risk of getting caught), closed shoes. A Japanese saw cuts on the pull; a Western one on the push. Drill on wood: high speed; on metal: low speed + oil. Always turn it off before changing the bit.

3. What is the difference between side brakes and central brakes? What do they imply when braking? Why is it not advisable to fit brakes on the wheels?

   Answer: 1) Difference between side and central brakes: with the side brake, the lever scrapes the ground on one side only; with the central brake, a single bar scrapes the ground at the back, on the rear axle. 2) Implication for braking: the side brake produces asymmetric braking (it tends to turn/steer the cart to one side); the central brake brakes symmetrically, making the cart stop in a straight line, with more stability. 3) Why not to fit brakes on the wheels: locking the wheel (and the bearing) makes the cart skid, can break the axle, and causes loss of steering control, especially at high speed. — A ground-scraping brake is simple and safe. The side type requires two levers (left+right) to stop straight, or pulling just one to turn. The central type is more predictable but reacts less. Locking a wheel in motion causes a skid (loss of grip) and easily breaks a thin-bar axle.

4. Complete your project, assembling it and finishing your cart with paint.

   Answer: Sand the wood (sandpaper 80, 120, 220), apply sealer, primer, then 2 coats of synthetic enamel paint with a 4-hour interval. Full drying in 24h. Protective varnish optional. Lubricate the axles after painting so they don't seize. — Synthetic enamel is more durable than PVA; it cures in 24h to the touch, 7 days fully. Progressive sanding (80→220) eliminates marks. Sealer closes the pores of the wood, saving paint. Marine varnishes resist weather better. Painting with a spray gun gives a more uniform finish.

5. Know how the friction, grip, and lubrication of the bearings affect its performance.

   Answer: The internal friction of the bearing slows the rolling (loses speed). The grip of the bearings on the asphalt provides traction and control. Lubrication (lithium grease) reduces internal friction, but excess attracts dirt; too little causes wear and overheating. — Spherical bearings have a friction of ~0.001 (vs. 0.4 in sliding). Lithium grease withstands 130°C. Clean with solvent every 3 months. Grip depends more on the ball-to-inner-race contact than on the street surface. Overheating is a symptom of lack of lubrication or axle misalignment.

6. Have a basic notion of first aid for cases of minor abrasions and of defensive driving regarding safety on curves and excessive speed.

   Answer: Wash the abrasion with saline solution or water and mild soap, dry it, apply antiseptic and a bandage. On a curve: slow down beforehand, exit accelerating. Excessive speed: the braking distance grows with the square of the speed. — A minor abrasion does not require stitches; washing it well prevents infection (Staphylococcus). On a descent, maintain an aerodynamic position and keep your eyes on the horizon (not on the track right ahead). A safe speed on a soapbox cart is up to 30 km/h; above that, the human reaction time (~0.8s) is no longer enough for tight curves.

7. Know which places are appropriate for training and testing your carts.

   Answer: Closed streets authorized by the city council, dedicated tracks in parks, flat vacant lots with a slight slope, isolated hills without intersections. Avoid open public roads, intersections, sidewalks with pedestrians, and wet asphalt. — The International Soapbox Federation recommends a 5-10% slope for beginners. Dry asphalt offers a friction coefficient of ~0.7; wet it drops to 0.3 — the braking distance doubles. Intersections require signaling and spotters. The soapbox festival in Itararé/SP is a national reference.

8. Participate in an event at your Club or district, observing the safety rules such as an appropriate location, personal protective equipment, and also sportsmanship.

   Answer: Mandatory PPE: full-face helmet, knee pads, elbow pads, gloves, and closed shoes. A location with signaling, spotters, and an ambulance. Sportsmanship: respect your opponent, no cutting them off, congratulate the winner, and help anyone who falls on the track. — A helmet reduces the risk of traumatic brain injury by 85% (a Cochrane study). Serious events require a technical inspection of the cart before the start (axle, brake, seatbelt). Federations recommend a minimum age of 8 years. Sportsmanship is the pillar of Scouting/Pathfinders and surpasses victory.