Gridfinity Sewing Thread Spool Tray — 6×3 Base, American Size Spools

A Gridfinity thread spool tray sized for American spools - 15 spools, stackable, and designed from scratch to fit your spools.

My sister liked the 30 x 40 Thread Spool Gridfinity Tray by @user_2287153542. That design is nicely executed for European-standard spools (30 mm x 40 mm), but standard American sewing thread runs larger: 35 mm in diameter and 45 mm tall. I built this spool tray from scratch in Fusion to accommodate those dimensions.

Design Details

The tray is a 6×3 Gridfinity base, 6u tall, holding 15 spools in a 5×3 arrangement. Each slot is sized to cradle a standard U.S. sewing thread spool (35 mm diameter, 45 mm height), keeping colors clearly visible. The slot geometry keeps spools secure without requiring a lid.

The trays stack - stack multiple trays, or combine with other Gridfinity storage on the same base grid. 

The two-color version adds a dark contrasting rim that gives the tray a polished, professional look. If you prefer a simpler print or a single-filament setup, the included single-color build plate produces a clean, fully functional tray.  I printed with 0.24mm layer heights, and used adaptive layer heights for smoother rounded curves.  The pictures are Bambu Lab PLA Matte Sky Blue with a PLA Matte Dark Blue contrasting rim.

Stack it, fill it, and find the right color on the first try.