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Stamp lifter: half-toothed pinion raising a rack and letting it fall

How does a stamp mill lift and drop its stamp? · Hardware · basis: Xem Studio design following Brown No. 351 (1868)

Also called: stamp mill mechanism, lift and drop mechanism, mutilated gear rack lifter, mecanismo de pisón, Stampfwerk (Pochwerk)

Exact dimensions. True size, with no printing tolerance added.

sizes
4 in table

Notes

  • 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.

Stamp lifter: half-toothed pinion raising a rack and letting it fall size chart

parametervalue
pinionmodule 1, 10 of 20 teeth
rack120 mm, module 1
lift per turn31.42 mm, then free fall
guide11.5 × 8 channel

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Henry T. Brown (1868, public domain)Five Hundred and Seven Mechanical Movements — scan on archive.orgwebPublisher's page; dimensions are facts
507movements.comBrown's movement No. 351: figure, his text and an animationwebPublisher's page; dimensions are facts

Free files

★ Free files 1 parts. Xem Studio design: free to use, print and sell things from; not to be republished as files. Xem Studio Design License. index.json

stamp-lifter-mechanism-assemblyAssembled mechanism, all parts placed at one pose (STEP keeps each part separate)STEP · STL
Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.
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Plain text: sheet.txt · JSON: /api/geometry?object=stamp-lifter-mechanism

Stamp lifter: half-toothed pinion raising a rack and letting it fall, isometric render of a generated part
Render of stamp-lifter-mechanism-assembly from the free STEP; not to scale.

Fits with

Mutilated pinion, module 1, 20 T with 10 teeth kept (half), isometric render of a generated part
Mutilated pinion, module 1, 20 T with 10 teeth kept (half)21.99×19.74×8.0 mm★ 1 file
Gear rack, module 1, 120 mm, full-depth 20° teeth, isometric render of a generated part
Gear rack, module 1, 120 mm, full-depth 20° teeth120.0×11.0×8.0 mm★ 1 file
Rack guide block 32 × 12 × 20 with an 11.5 × 8 through channel, isometric render of a generated part
Rack guide block 32 × 12 × 20 with an 11.5 × 8 through channel32.0×12.0×20.0 mm★ 1 file
Dowel pins, 2–6 mm (ISO 2338 / DIN 6325), isometric render of a generated part
Dowel pins, 2–6 mm (ISO 2338 / DIN 6325)5 sizes★ 23 files

Questions

How does a stamp mill lift and drop its stamp?

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.