Round-belt generator drive: Ø84 crank pulley, 2208 generator pulley, Ø5 belts — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/round-belt-generator-drive/  (CC BY 4.0)
Basis: Design values; 2208 rotor-top hole pattern from the gimbal-motor envelope on this site
Catalog version: 2026-10-20

Sizes: see table below
- A Ø5 round belt from an Ø84 crank pulley (pitch Ø80) to an Ø16 pulley (pitch Ø13.33) bolted to a 2208 gimbal motor's rotor top: 6 : 1, so 600 rpm at the crank is 3600 rpm at the generator.
- Belt lengths on the centre line: 339.1 mm at 90 centres (horizontal gamma), 415.2 mm at 130 (walking-beam gamma). Round belts are cut to length and joined; tension by stretch.
- The belt and pulleys turn the crank's shaft power into motor speed; the electrical output on each engine's page comes from the motor's published KV and resistance.

part  size
crank-pulley-84-b8  Ø84 × 6, pitch Ø80, hub Ø20
generator-pulley-2208-pd13.33  Ø16 × 8, pitch Ø13.33
round-belt-5-c90  Ø5 × 339.1
round-belt-5-c130  Ø5 × 415.2

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 4 parts): https://xemstudio.com/files/hardware/round-belt-generator-drive/index.json
API: https://xemstudio.com/api/geometry?object=round-belt-generator-drive