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Double-helical (herringbone) gear, normal module 1.5, 30 teeth, helix 20° , face 16, Ø8 bore
What are the dimensions of a 30-tooth, 20° double-helical (herringbone) gear? · Modern device · basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance
Also called: herringbone gear, double helical gear, engranaje bihelicoidal (espina de pescado), Pfeilzahnrad
Exact dimensions. True size, with no printing tolerance added.
- length
- 50.89 mm
- width
- 50.89 mm
- height
- 16.0 mm
Notes
- Normal module 1.5, helix angle 20°: transverse module 1.6, transverse pressure angle 21.17°, pitch Ø47.89, tip Ø50.89, root Ø44.14; addendum 1.5, dedendum 1.88 (normal-module depths).
- Two opposed 20° helices meet at mid-face (twist 6.97° each way over 8 mm), so the end thrusts cancel.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).
Double-helical (herringbone) gear, normal module 1.5, 30 teeth… size chart
| dimension | value |
|---|---|
| normal module | 1.5 |
| teeth | 30 |
| helix angle | 20° |
| transverse module | 1.6 |
| pitch Ø | 47.89 mm |
| tip Ø | 50.89 mm |
| face | 16 mm |
| bore | Ø8 |
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. 41: 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
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=double-helical-gear-mn1-5-30t-beta20-bore8
Fits with
Questions
What are the dimensions of a 30-tooth, 20° double-helical (herringbone) gear?
Normal module 1.5, helix angle 20°: transverse module 1.6, transverse pressure angle 21.17°, pitch Ø47.89, tip Ø50.89, root Ø44.14; addendum 1.5, dedendum 1.88 (normal-module depths).