Sun-and-planet arm, 30 mm centres, Ø10 holes — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/sun-and-planet-arm-30/  (CC BY 4.0)
Basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance
Catalog version: 2026-10-20

Overall (mm): length 48.0, width 18.0, height 5.0
- 18 × 5 mm arm with two Ø10 holes 30 mm apart: it turns on the sun's Ø10 shaft and on the planet's boss and only keeps the two gears in mesh (centre distance 30 mm for two module 1, 30-tooth gears).
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
centres  30 mm
holes  2 × Ø10
section  18 × 5 mm

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. 39: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_039.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/sun-and-planet-gear-mechanism/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/sun-and-planet-arm-30/index.json
API: https://xemstudio.com/api/geometry?object=sun-and-planet-arm-30