Mutilated bevel gear driving two bevel gears alternately, opposite ways — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/mutilated-bevel-gear-mechanism/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Xem Studio design following Brown No. 74 (1868)
Catalog version: 2026-10-20

Sizes: see table below
- A bevel gear with teeth on only half its rim turns continuously between two bevel gears facing each other: for half a turn its teeth drive one, for the other half the other. The two driven gears face opposite ways, so they turn in opposite directions, each moving half a turn and then resting.
- Three module 2, 20-tooth spherical-involute mitre gears (one with 10 teeth cut away), cone distance 28.28 mm; drawn with the toothed half in mesh with gear A, gear B free.
- Brown's No. 74. The driven gears here turn on separate stub shafts so each can rest independently.
- Parts (each has its own page): mitre-gear-m2-20t-bore5-half-teeth, mitre-gear-m2-20t-bore5, dowel-pins-metric.
- Brown's movement No. 74 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

parameter  value
driver  mitre, 10 of 20 teeth
driven  2 × mitre 20 T
each driven gear  half a turn, then rest

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. 74: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_074.html

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/mutilated-bevel-gear-mechanism/index.json
API: https://xemstudio.com/api/geometry?object=mutilated-bevel-gear-mechanism