Rack guide block 32 × 12 × 20 with an 11.5 × 8 through channel — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/rack-guide-block-32x12-ch11-5x8/  (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 32.0, width 12.0, height 20.0
- 32 × 12 × 20 block with an 11.5 × 8 mm channel through it: the module 1 rack (8 wide) slides in it with its back line on line against the channel wall and its tooth tips 0.5 mm clear of the other; two Ø3.4 mounting holes.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
block  32 × 12 × 20 mm
channel  11.5 × 8 mm
holes  2 × Ø3.4

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
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/stamp-lifter-mechanism/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/rack-guide-block-32x12-ch11-5x8/index.json
API: https://xemstudio.com/api/geometry?object=rack-guide-block-32x12-ch11-5x8