Speed Square Rafter Design for Metric User — 3D Print STL and 3MF Prototype design V1.0

In 1925, Albert J. Swanson invented the Speed Square — part rafter square, part protractor, part marking guide. It became the carpenter’s pocket tool in the US. But here’s the catch: it was born in the Imperial system. Great if you’re framing in inches. Not so great if you’re working in metric.

So I designed my own in 2025:

• All-metric rafter square

• Rise/run markings for common rafters, hip/valley cuts, and top notch

• Printable as a solid jig or lightweight frame

WHAT INCLUDED:

• Hip/Valley system include Ratio system as well as Metric system
• 20 centimeter long main ruler
• 10 centimeter long increment ruler
• Degree system up to 90 degree with 1 degree increment
• Both label in English and Indonesian
• Middle Diamond Notch at 10 cm mark
• Triangle Jig for sizing angled pipe
• Scribble notch for main ruler increment at 1 mm
• 5 mm lip thickness with insertion notch for the main Square
• Separated Main Lip Print and Main ruler print
• Double-sided labels