Xem Studiomeasured geometry

Library › Hardware › Mechanism parts ·

Helical gear, normal module 1.5, 30 teeth, helix 20° left hand, face 12, Ø8 bore

What are the dimensions of a 30-tooth, 20° helical gear? · Modern device · basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance

Also called: helical gear, oblique tooth gear, helical gear module 1.5, engranaje helicoidal, Schrägstirnrad

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

length
50.89 mm
width
50.89 mm
height
12.0 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).
  • The transverse involute is twisted 10.45° over the 12 mm face (lead π·d / tan β = 413.34 mm). Meshes with a 20-tooth gear of the opposite hand on a parallel shaft.
  • Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

Helical gear, normal module 1.5, 30 teeth, helix 20° left hand, face… size chart

dimensionvalue
normal module1.5
teeth30
helix angle20° LH
transverse module1.6
pitch Ø47.89 mm
tip Ø50.89 mm
face12 mm
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. 40: 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

helical-gear-mn1-5-30t-beta20-lh-bore8gear, axis Z, z 0..12, a tooth on +X at z = 0STEP · 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=helical-gear-mn1-5-30t-beta20-lh-bore8

Helical gear, normal module 1.5, 30 teeth, helix 20° left hand, face 12, Ø8 bore, isometric render of a generated part
Render of helical-gear-mn1-5-30t-beta20-lh-bore8 from the free STEP; not to scale.

Fits with

Helical (oblique-toothed) gears on parallel shafts, 20 : 30, helix 20°, isometric render of a generated part
Helical (oblique-toothed) gears on parallel shafts, 20 : 30, helix 20°5 sizes★ 1 file

Questions

What are the dimensions of a 30-tooth, 20° helical 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).