Summary

Lewmar Track Stop Bumper Replacement
Replace your worn‐out Lewmar track stop buffers (PN 29472046BK Size 2 NTR Buffer) with these 3D‑printed soft bumpers, designed to fit standard jib‑car and traveler track stops on sailboats.

Overview
Lewmar track stops use soft rubber bumpers to absorb impacts from cars running on jib and traveler tracks. Stock bumpers typically last around two years before tearing apart, and replacements cost about $12 each. This model is a cost‑effective, in‑house alternative you can print on demand.

Features
Exact form‑fit to Lewmar track stops
Replaceable, soft‑impact bumper in TPU or TPE
Cost‑effective: virtually zero per‑piece cost
Customizable durability: switch filament based on UV and saltwater resistance

Print Settings
Printer: Bambu X1C
Nozzle: 0.4 mm
Layer height: 0.16 mm
Infill: 20-30 % gyroid or cubic (for a balance of flexibility and strength)
Walls: 3-5 perimeters (for a balance of flexibility and strength)

Materials & Durability
Primary filament: Bambu Black TPU for ease of print and acceptable elasticity and damping. UV durability test is in progress.
Alternative filament: Kimya Black TPE, tested for survivability in marine environment for 2 years. Cannot be used with AMS.
Pro tip: Black pigment enhances UV stability. Avoid white, grey, or other light colors—these have degraded within two years aboard my sailboat.

Notes
Longevity will vary with exposure: continuous sun and salt spray may accelerate wear.
Adjust hardness by tweaking perimeters / infill settings or trying different TPU/TPE grades. However these will NOT be nearly as soft as originals.
Fusion 360 model included. Feel free to remix - adjust dimensions for different track size, etc.

Fair winds and smooth sailing!