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Face spiral (scroll) disc, pitch 4.71 (module 1.5), r 30 → 48.85, Ø104 × 6

What is a face spiral disc? · Modern device · basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance

Also called: face spiral, scroll, spiral disc, face worm, scroll plate, disco con espiral frontal (caracol), Spiralscheibe (Schnecke auf der Stirnseite)

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

length
104.0 mm
width
104.0 mm
height
9.38 mm

Notes

  • A Ø104 × 6 disc with one raised Archimedean spiral rib on its face: radial pitch p = π m = 4.71 mm, from radius 30 to 48.85 (4 turns), Ø8 bore. The rib's radial section is the basic rack of module 1.5 (20° flanks, πm/2 thick at its pitch height 1.88 mm above the face, top at 3.38 mm): seen by a toothed part standing over the face, the rib is a rack that advances p per turn of the disc — a worm unrolled onto a face.
  • Swept along the spiral with the profile kept upright and normal to the path; the bottom of the rib runs 0.5 mm into the disc so it is one solid.
  • Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

Face spiral (scroll) disc, pitch 4.71 (module 1.5), r 30 → 48.85… size chart

dimensionvalue
pitch p4.71 mm (module 1.5)
spiralr 30 → 48.85, 4 turns
rib height3.38 mm above the face
discØ104 × 6
boreØ8

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. 29: figure, his text and an animationwebPublisher's page; dimensions are facts
Xem StudiodrawingwebPublisher'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

face-spiral-disc-m1-5-r30-4turns-d104disc, axis Z, face at z = 0, rib up to z = 3.38STEP · 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.
Set it up →

Plain text: sheet.txt · JSON: /api/geometry?object=face-spiral-disc-m1-5-r30-4turns-d104

Face spiral (scroll) disc, pitch 4.71 (module 1.5), r 30 → 48.85, Ø104 × 6, isometric render of a generated part
Render of face-spiral-disc-m1-5-r30-4turns-d104 from the free STEP; not to scale.

Fits with

Face spiral (scroll) on a disc turning a wheel one tooth per turn (24 : 1), isometric render of a generated part
Face spiral (scroll) on a disc turning a wheel one tooth per turn (24 : 1)5 sizes★ 1 file

Questions

What is a face spiral disc?

A Ø104 × 6 disc with one raised Archimedean spiral rib on its face: radial pitch p = π m = 4.71 mm, from radius 30 to 48.85 (4 turns), Ø8 bore. The rib's radial section is the basic rack of module 1.5 (20° flanks, πm/2 thick at its pitch height 1.88 mm above the face, top at 3.38 mm): seen by a toothed part standing over the face, the rib is a rack that advances p per turn of the disc — a worm unrolled onto a face.