Pivot post 16 × 20 × 30 with a 12.1 mm fork and Ø5 pin hole — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/pivot-post-16x20x30-fork/  (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 16.0, width 20.0, height 30.0
- 16 × 20 × 30 post whose top 12 mm is a fork 12.1 mm wide (the 12 mm helve swings in it) with a Ø5 pin hole 24 mm up; the helve's pivot.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
post  16 × 20 × 30 mm
fork  12.1 mm wide, 12 deep
pin hole  Ø5 at z 24

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. 353: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_353.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/trip-hammer-mechanism/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/pivot-post-16x20x30-fork/index.json
API: https://xemstudio.com/api/geometry?object=pivot-post-16x20x30-fork