Stamp lifter: half-toothed pinion raising a rack and letting it fall — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/stamp-lifter-mechanism/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Xem Studio design following Brown No. 351 (1868)
Catalog version: 2026-10-20

Sizes: see table below
- A pinion with teeth on only half its rim meshes with a rack on the vertical stamp rod: while the toothed half is engaged the rod is lifted (half a turn = 10 pitches = 31.4 mm), then the blank half comes round, the rack is free and the stamp drops under its own weight.
- Catalog parts: the module 1 pinion with 10 of 20 teeth and the 120 mm full-depth rack, pinion axis 10 mm from the rack's pitch line; drawn with the toothed half meshing and the rack in a guide block.
- Brown's No. 351 (stamp: shaft with a part-toothed wheel lifting a rack and letting it fall).
- Parts (each has its own page): mutilated-pinion-m1-20t-half, gear-rack-m1-120-full-depth, rack-guide-block-32x12-ch11-5x8, dowel-pins-metric.
- Brown's movement No. 351 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

parameter  value
pinion  module 1, 10 of 20 teeth
rack  120 mm, module 1
lift per turn  31.42 mm, then free fall
guide  11.5 × 8 channel

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. 351: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_351.html

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