Crossed flat belt 12 × 1.5 for Ø40 and Ø80 pulleys at 160 mm (loop drawn on the pulleys) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/crossed-flat-belt-12x1-5-pulleys-40-80-c160/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance
Catalog version: 2026-10-20

Overall (mm): length 223.0, width 83.0, height 12.37
- Flat belt 12 × 1.5 mm crossed between Ø40 and Ø80 pulleys 160 mm apart: inside length = 2√(C² − (R₁ + R₂)²) + (R₁ + R₂)(π + 2·asin((R₁ + R₂)/C)) = 531.27 mm.
- Each strand turns half a turn about its own length so the same face runs on both pulleys; the strands lie flat on each other where they cross (drawn 0.1 mm apart).
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
width × thickness  12 × 1.5 mm
inside length  531.27 mm
for  Ø40 + Ø80 at 160 mm, crossed

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Henry T. Brown (1868, public domain): Five Hundred and Seven Mechanical Movements — scan on archive.org — web — Publisher's page; dimensions are facts — https://archive.org/details/fivehundredseven00browiala
- 507movements.com: Brown's movement No. 2: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_002.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/crossed-belt-drive-mechanism/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/crossed-flat-belt-12x1-5-pulleys-40-80-c160/index.json
API: https://xemstudio.com/api/geometry?object=crossed-flat-belt-12x1-5-pulleys-40-80-c160