Guide pulley Ø28.28 × 12, Ø6 bore (plain face) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/plain-flat-pulley-28-28x12-bore6/  (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 28.28, width 28.28, height 12.0
- Plain Ø28.28 × 12 pulley (Ø6 bore) for the right-angle guide-pulley drive: for two Ø40 pulleys whose belt lines run parallel, the guide's diameter is the distance between the strands it joins, 20√2 = 28.28 mm.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
face  Ø28.28 × 12 mm
bore  Ø6

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. 3: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_003.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/guide-pulley-right-angle-belt-mechanism/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/plain-flat-pulley-28-28x12-bore6/index.json
API: https://xemstudio.com/api/geometry?object=plain-flat-pulley-28-28x12-bore6