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Wheel for a face spiral, module 1.5, 24 teeth, generated by the scroll at radius 39

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

Also called: face spiral wheel, scroll wheel, generated spur wheel, rueda para espiral frontal, Rad für Spiralscheibe

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

length
38.85 mm
width
38.85 mm
height
8.0 mm

Notes

  • 24-tooth wheel of module 1.5 (pitch Ø36, tip Ø39, root Ø32.25, 8 mm face, Ø6 bore) whose teeth were generated by the spiral rib itself: in every plane across the face the rib's section (a rack tooth that is slightly wider and farther out away from the disc's centre line) was swept past the turning wheel and the envelope taken, then the seven sections lofted (spline fit within 0.108 mm). The result is an involute-like tooth that is very slightly curved and thinner across the face — the exact mate of the rib at radius 39, where a plain straight spur gear would bind at the face edges.
  • One tooth per turn of the disc; the wheel's axis lies parallel to the disc face, tangent to the spiral at the mesh.
  • Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

Wheel for a face spiral, module 1.5, 24 teeth, generated by the… size chart

dimensionvalue
module1.5
teeth24
pitch Ø36 mm
tip / root Ø39 / 32.25 mm
face8 mm
boreØ6
mesh radius on the disc39 mm

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-wheel-m1-5-24t-for-scroll-r39wheel, axis Z, z -4..4, a space centred on +XSTEP · 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=face-spiral-wheel-m1-5-24t-for-scroll-r39

Wheel for a face spiral, module 1.5, 24 teeth, generated by the scroll at radius 39, isometric render of a generated part
Render of face-spiral-wheel-m1-5-24t-for-scroll-r39 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 wheel runs on a face spiral?

24-tooth wheel of module 1.5 (pitch Ø36, tip Ø39, root Ø32.25, 8 mm face, Ø6 bore) whose teeth were generated by the spiral rib itself: in every plane across the face the rib's section (a rack tooth that is slightly wider and farther out away from the disc's centre line) was swept past the turning wheel and the envelope taken, then the seven sections lofted (spline fit within 0.108 mm). The result is an involute-like tooth that is very slightly curved and thinner across the face — the exact mate of the rib at radius 39, where a plain straight spur gear would bind at the face edges.