Design available to download on Cults3d -Click Here
 
Smooth, sturdy seat travel for home cockpits using 608 bearings + MDF channels
Description
This is Karl’s original design for Boeing 737 “J” seat rails tailored for home cockpit builders. Each side uses four rolling truck assemblies running on cheap, ubiquitous 608 skate/roller bearings to deliver silky-smooth fore–aft seat movement. The lower trucks lock the seat down to prevent lift-off or accidental detachment, while the main structural loads are taken by through‑bolts in each assembly. Two guide bearings inside the rail maintain alignment and stability.
Prototypes printed in PLA at 25% infill have proven more than adequate to support most people’s weight in typical simpit use. This design focuses on reliable motion, easy cockpit access, and low-cost fabrication versus expensive commercial rail solutions.
The trucks are designed to run in MDF channels, and the download includes a router/jigsaw guide template to make cutting those channels the only “tricky” step. To lock positions, a multi‑stop channel block is included; pair it with a spring‑loaded gate pin/handle mounted to the seat (sourced from any hardware store) for positive engagement in multiple detents.
Compatibility: Designed for Boeing 737 home cockpits. A full‑size mock seat is included for reference. First Officer side: simply mirror/flip the template.
Coming soon: a variant tailored to Ipeco seats (this download already includes the mock seat model for sizing/fit checks).
What’s Included
Truck assemblies (upper & lower) – STL files
Rail/channel cutting guide (router/jigsaw template) – STL/DXF as applicable
Multi‑stop channel block – STL
B737 mock full‑size seat – STL for reference/sizing
Build notes (within listing + embedded file names)
(If you’d like a separate printable PDF build guide, say the word and I’ll format one.)
Recommended Hardware & Materials
Bearings: 608 (8×22×7 mm) skate/roller bearings
Tip: Use decent quality sealed bearings for longevity and smoothness.
Bolts/axles: Match the 608 inner bore (8 mm); use washers and nyloc nuts where appropriate
Seat index pin: Spring‑loaded gate pin/handle (hardware-store part) for the multi‑stop block
Rails: MDF channels cut using the supplied router/jigsaw guide
Print Settings (Proven & Recommended)
Material: PLA works (tested at 25% infill); PLA+ or PETG recommended for better toughness
Perimeters: 4–6 walls (as recommended)
Infill: ≥25% (increase for heavier users or higher duty cycles)
Layer height: 0.2 mm typical (0.16–0.28 mm ok)
Orientation: Print truck bodies for maximum layer strength along load paths
Post‑processing: Deburr bearing bores; ensure free‑running, no pinch points
Installation & Use
Cut the MDF channels using the included router/jigsaw guide.
Assemble the trucks with 608 bearings and 8 mm hardware; confirm smooth rolling.
Install the lower trucks to prevent lift‑off and secure the seat to the rails.
Fit the guide bearings so trucks run centrally with no side‑to‑side play.
Mount the multi‑stop block and fit the spring‑loaded pin to the seat base for positional detents.
Mirror the templates to create a First Officer side if required.
Why This Design (Originality & Essentials)
Purpose-built for sims: Optimized for B737 simpits with common tools and materials
Affordable & accessible: Uses readily available 608 bearings and MDF rails
Smooth + secure: Guided trucks and lower lock‑down assemblies control lift and misalignment
Builder‑friendly: Includes cutting guide and multi‑stop block—no guesswork on detents
Proven in PLA: Real‑world prototypes at 25% infill supporting most users
Context of Use
Home flight simulators and DIY cockpit projects (B737 layouts)
Suited for regular sim sessions, easy ingress/egress, and repeatable seat positioning
Not intended for real aircraft or industrial seating
Limitations & Safety Notes
Load capacity depends on print quality, material, infill, wall count, hardware, and assembly technique.
Designed for MDF channels; performance varies with routing precision and surface finish.
Inspect regularly for wear, cracks, or bearing degradation—replace parts if damaged.
Not certified for safety-critical applications; hobby use only.