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Crown wheel (face gear), module 1.5, 54 teeth, generated by an 18-tooth spur pinion
How are the teeth of a crown wheel shaped? · Modern device · basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance
Also called: crown wheel, face gear, contrate wheel, crown gear, rueda de corona (engranaje frontal), Kronenrad
Exact dimensions. True size, with no printing tolerance added.
- length
- 89.0 mm
- width
- 89.15 mm
- height
- 9.63 mm
Notes
- Face gear: 54 teeth standing on the face of a Ø89 disc (Ø8 bore), from radius 37.5 to 44.5 mm, each tooth the envelope of the module 1.5, 18-tooth involute spur pinion it runs with (the catalog gear, its own root form included): the pinion's axis lies in the wheel's pitch plane, 13.5 mm (its pitch radius) above the tooth-root plane's offset, and the pair turns at 3 : 1 while the pinion's teeth sweep the spaces — computed in 7 planes across the face at 0.25° steps and lofted through them (spline fit within 0.008 mm).
- Tooth top at +1.5 mm above the pitch plane, space bottom at −1.875 mm (0.25 m clearance under the pinion's tip); the toothed band is a 54-gon, so every tooth ends flat at its own inner and outer radius. The tooth form changes across the face: wider and undercut toward the centre, pointed toward the rim — which is why a face gear's face width is short (here 7 mm, from 3 modules inside the nominal pitch radius 40.5 to 4 outside).
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).
Crown wheel (face gear), module 1.5, 54 teeth, generated by an… size chart
| dimension | value |
|---|---|
| module | 1.5 |
| teeth | 54 |
| pinion | 18 T spur (catalog gear-m1-5-18t), axis in the pitch plane |
| face | r 37.5 → 44.5 mm (7 mm) |
| tooth top / root | +1.5 / −1.875 mm from the pitch plane |
| disc | Ø89 × 6 under the teeth, Ø8 bore |
| ratio | 3 : 1 |
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.org | web | Publisher's page; dimensions are facts |
| 507movements.com | Brown's movement No. 26: figure, his text and an animation | web | Publisher's page; dimensions are facts |
| Xem Studio | drawing | web | Publisher'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
| crown-wheel-m1-5-54t-for-18t-pinion | crown wheel, axis Z, pitch plane z = 0, a space centred on +X | STEP · STL |
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.Plain text: sheet.txt · JSON: /api/geometry?object=crown-wheel-m1-5-54t-for-18t-pinion
Fits with
Questions
How are the teeth of a crown wheel shaped?
Face gear: 54 teeth standing on the face of a Ø89 disc (Ø8 bore), from radius 37.5 to 44.5 mm, each tooth the envelope of the module 1.5, 18-tooth involute spur pinion it runs with (the catalog gear, its own root form included): the pinion's axis lies in the wheel's pitch plane, 13.5 mm (its pitch radius) above the tooth-root plane's offset, and the pair turns at 3 : 1 while the pinion's teeth sweep the spaces — computed in 7 planes across the face at 0.25° steps and lofted through them (spline fit within 0.008 mm).