Plain flat-belt pulley Ø40 × 66 face, Ø8 bore (no flanges) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/plain-flat-pulley-40x66/  (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 40.0, width 40.0, height 66.0
- Ø40 × 66 mm straight face, Ø8 bore, no flanges: the face is exactly the belt's width, so a twisted belt can leave it at an angle (quarter-turn and guide-pulley drives) without riding over a flange.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
face  Ø40 × 66 mm
bore  Ø8
flanges  none

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. 256: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_256.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/quarter-turn-belt-drive-mechanism/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/plain-flat-pulley-40x66/index.json
API: https://xemstudio.com/api/geometry?object=plain-flat-pulley-40x66