Reverse Engineered Smart Rack (Hinge & End Caps)

This is a reverse-engineered smart rack for 2.25" American pool balls, inspired by the 8 Ball Direct Smart Rack.
It features precision-fit parts, built-in hinge stoppers for easier setup, and modular assembly with aluminum flat bars.

Key Features:

• ⚙️ Two-part custom hinge with heat-set insert and M5 x 40mm bolt
• 🧱 Fits two 11” x 2” x 1/8” aluminum flat bars (one per side)
• 🧲 End caps with four 6mm magnets (two per cap) for secure closure
• 🛑 Built-in hinge stoppers limit opening angle slightly—makes placement and tight racking easier
• 📐 Designed from scratch based on 15-ball rack geometry
• 🧴 Assembled using Scotch gel super glue

Built entirely from scratch for hobby use only. Remix or modify as you like!

Bill of Materials:

• (2) 11” x 2” x 1/8” aluminum flat bars
• (4) 6mm diameter magnets (2 per end cap)
• (1) M5 x 40mm (see below for alternative) socket head bolt
• (1) M5 heat-set insert
• Scotch gel super glue

Included Files:
Includes a STEP file for users who want to tweak or redesign components.

Note:
The STEP file includes the aluminum flat bars for reference only. These are not 3D printed—each side requires one 11” x 2” x 1/8” aluminum flat bar, to be sourced separately.

Assembly Tip:
If your aluminum flat bars aren't cut perfectly square, you may notice slight end cap misalignment.
To fix this:

1. Insert the magnets into the end caps first
2. While the glue at the flat bar interface is still wet, shift the bars slightly—the magnets will help auto-align the ends for a cleaner final fit

Insert Placement Note:
As seen in the photos, the heat-set insert is installed from the top of the lowest hinge loop. This was necessary due to using a 40mm M5 bolt (only bolt I had on hand), which limited thread reach.
For better thread engagement, using a 50mm bolt allows the insert to be placed from the bottom of the hinge loop instead—this is the preferred setup.

Also note:

• Insert outer diameters vary slightly depending on brand
• Adjust the insert hole in CAD if needed to avoid excessive material displacement when heat-setting
  The included STEP file makes these edits simple if you want to dial in a perfect fit.

Compatibility:
Works with standard 2.25" American pool balls and any smaller sizes. Larger ball sets may extend slightly past the end caps in the final row.