Pinewood Derby Axle Finishing & Alignment Guide

Step-by-Step Process

1. Straighten — Initial Alignment

1. Insert axle head-first into the Derby Worx Pro Axle Press.
2. Tap lightly with a small hammer until the head seats flush, rotate 180°, tap again.
3. This squares the head to the shaft and removes factory bend.

2. Burr Removal — Shaft Cleanup

1. Lay axle horizontally in the press channel (acts as a mini V-block).
2. File along the shaft with a barrette fine-tooth jeweler’s file (safe-back) to remove seam lines and plating nibs.
3. Inspect under 10× magnification; stop as soon as the seam disappears.

3. Crimp Removal — Flatten the Head Underside

1. Seat axle vertically in the press for perfect stability.
2. File or stone the underside of the head until crimp rings are gone.
3. Finish flat with a hard Arkansas or ceramic stone; optional micro-chamfer using folded 1000-grit paper.

4. Re-Straighten & Cold-Form

1. Reinsert each axle into the press, give two light hammer taps to verify alignment.
2. Deliver controlled micro-taps on the head to cold-form and harden geometry (impact forming).

5. Wet Sand — Progressive Abrasives

1. Mount axle in a drill or pin vise at 200 – 600 RPM.
2. Wet-sand through 400 → 800 → 1000 → 1500 → 2000 grit using water + drop of soap.
3. Keep motion steady and even; don’t dwell in one spot.

6. Final Finish — Cotton Butcher’s String Polish (Derby Dust® Preferred Method)

1. Mount the axle at low RPM (200 – 400).
2. Load cotton butcher’s string with a small amount of jeweler’s rouge, green chromium, or diamond paste.
3. Wrap the string once or twice around the shaft — loose, not crossed — and let it glide as the axle spins.  DO NOT WRAP AROUND YOUR FINGERS as method to hold!  It is not dental floss.  
4. Move smoothly back and forth; the string conforms to micro low spots and polishes uniformly.
5. Clean with lint-free pad and isopropyl alcohol (90 %+).

Why it works: the cotton fibers act like thousands of flexible micro-belts, creating a mirror finish without rounding edges or overheating the metal — exactly how jewelers polish fine pins and watch stems.

Optional — Micro Finish Under Head

Use a short length of loaded string or soft felt pad held perfectly flat under the head to refine the hub contact surface.

Storage & Race Prep

1. If storing: apply a light rust-preventative oil or Derby Dust® Axle Sealer.
2. Before racing: remove oil film and burnish with Graphite + MoS₂ Blend or pure graphite depending on rules.

7. Performance Summary

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