Build a Derby car from the rule book up

ILLUSTRATED BUILD MAP

The floorboard is a dependency map, not a blank fabrication panel.

Open the official plan beside this drawing. Every location, hole, stack, dimension, fastener, adhesive area, and body operation comes from that plan, not from this orientation schematic.

READ THIS FIRST

This course teaches workflow; the official plan supplies the car.

Choose the sanctioning body and division before opening a hardware bag. Keep the live rule book, current division plan, season changes, and inspection guidance at the bench. Follow each official figure in order and let the racer perform age-appropriate work with an adult supervising tools, chemicals, lifting, and safety-critical checks.

Stop-work rule: if a step requires a cut, drilled hole, epoxy, filler, laminate, substituted fastener, axle work, or body change that is not plainly shown in the current plan, stop before doing it and obtain written guidance.

CHOOSE THE LEGAL BUILD PATH

The same shop technique can be legal in one division and disqualifying in another.

Conflict example: an older Stock plan includes an optional-finish section, while the current live division page says Stock shells cannot be painted. The current official rule stack controls; use an authorized written clarification to resolve ambiguity, never an informal override.

THE COMPLETE BUILD SEQUENCE

Finish each dependency before covering it.

1. Freeze the rule set. Record organization, division, event, plan URL, revision, season changes, inspection sheet, and the person who will answer an ambiguity.
2. Fit before fastening. Put the fully dressed racer beside the unbuilt car and plan legal foot-brace, steering, brake, helmet, sight-line, and exit needs before committing adjustable positions.
3. Inventory by official step. Match every bag and part to the plan photo. Separate look-alike washers and bolts; never substitute by appearance.
4. Map the floorboard. Confirm top, front, branded surface, existing holes, recesses, and the official sequence. Photograph it before the first assembly.
5. Install bushings and running-gear references. Use the plan's temporary draw-through fixture and only its permitted adhesive method. Keep the bushing and kingpin functions separate.
6. Build steering and brake controls. Assemble mounts, pulleys, cable, clamps, adjusters, steering stops, brake hardware, and safety-retained parts exactly as pictured.
7. Install axle support hardware. Fit the Stock stabilizer, Super Stock angle iron, or Masters plate option shown for the chosen car. Preserve logos and inspection access.
8. Establish geometry. Set neutral steering, triangulate plan-defined references, verify cross-plane state, and record loaded spindle direction before final shell work.
9. Fit and secure legal weight. Use only listed areas, holes, plates, clearances, and fasteners. Weigh the complete car and dressed racer with practical inspection margin.
10. Fit the body and driver protection. Trim, drill, glue, screw, foam, hatch, and airfoil parts only where the plan directs. Recheck control travel and exit after each body stage.
11. Finish and identify. Apply only the division's permitted paint, wax, marker, decal, wrap, filler, or composite process while leaving fasteners, labels, and inspection points visible.
12. Inspect, shake down, and baseline. Complete the official checklist, a static control check, a supervised low-speed stop, a vibration inspection, final scales, and a documented track baseline.

BUSHINGS AND EPOXY

Locate the bushing; do not manufacture a new hole with glue.

STEERING CABLE THAT STAYS CONSISTENT

Seat the assembled system; never invent a stretch load.

1. Official plan: identify left and right routing, pulley order, shaft wrap direction and count, axle attachment, clamps, adjuster, loose-end treatment, and steering-stop travel from the exact plan figures.
2. Official plan: center the steering wheel and axle before final adjustment. Confirm a right steering input turns the axle right and the cable cannot cross, rub, fray, or interfere with the brake.
3. Shop practice to confirm: with the completed car safely supported and an adult at the controls, cycle normal steering travel smoothly several times. This seats wraps, clamps, and adjusters so constructional slack appears at the bench.
4. Shop practice to confirm: return to neutral, inspect every wrap and clamp, and recheck permitted tension. Repeat the cycle until the neutral and response repeat.
5. Official safety gate: steering must respond immediately through legal travel without bowing the front axle, binding, overtravel, or changing the axle reference.

Concrete official-plan example: the current Stock plan shows a specific 180-degree plus 360-degree shaft-wrap sequence. That illustration, not a generic verbal shortcut, controls a Stock build. Masters and Legacy use their own routing and attachment instructions.

Do not hang weight from a cable, tow against it, preload through the axle, or publish a universal force or time. The safe teaching goal is seating the assembled wraps, clamps, and adjusters, then rechecking them without axle bow.

FLOORBOARD, SCREWS, BODY TIGHTNESS, AND VIBRATION

Structure comes from plan-correct assembly, not mystery reinforcement.

The official Stock sequence alternates body tightening from front toward rear and requires the body to finish tight against the floorboard; Masters has its own minimum approved screw pattern and placement rules. Copy the exact current division figure. Floorboard stiffness, screw placement, shell contact, and clamp state can change vibration and whether geometry repeats, but they are records, not free tuning variables.

Build a numbered fastener map using the plan's existing positions. With the car safely supported, use a gentle hand check to find shell movement, rattling hardware, cable contact, brake contact, or a weight plate that can move. Never spin wheels or strike the body as a substitute for inspection.

TAIL WEIGHT, NOSE WEIGHT, AND CENTER OF GRAVITY

Balance the complete racer-car system, not an empty shell.

Set legal mass only after driver fit, steering, brake, body, and hardware are complete. The front-to-rear scale difference and fore-aft center of gravity move when the racer's hips, feet, hands, and helmet move. There is no universal fast tail-weight target.

1. Zero a coplanar scale setup and record the dressed racer's repeatable posture.
2. Measure front, rear, all four corners, total, and reaction spacing using one declared method.
3. Compare the result with the current division's official total and distribution rules.
4. Choose only a plan-permitted fixed or adjustable weight location and attachment.
5. Predict the direction before moving one known mass; then reweigh and compare with ordinary scale spread.
6. Leave inspection margin and recheck steering, brake, clearance, fasteners, and driver exit.

GRAPHICS, PAINT, BONDO, AND COMPOSITES

Finish the legal surface without turning decoration into construction.

Take finish photographs before and after every body stage. A beautiful surface is not complete until every screw, washer, logo, access opening, and required measurement remains inspectable.

EXAMPLE-LED QUALITY GATES

Use the failure before it reaches the hill.

INSPECTION, SHAKE-DOWN, AND RACE-DAY CHECKS

A finished car is one another adult can verify.