Spur Gear GeometryModule, pitch diameter, centre distance and the meshing condition.Mechanical EngineeringModule sets tooth size, and two gears mesh only ifthey share a module and a pressure angle.m = d ÷ z · centres = m(z1 + z2) ÷ 2m = 2 mm, z = 40Pitch diameter 80 mmd = m times z.z1 = 20, z2 = 60, m = 2Centres at 80 mmHalf the sum of d.Same pairRatio 3 to 1Torque up, speed down.THE COMMON MISTAKEMixing module with diametral pitchThey are reciprocals in different unitsModule is millimetres per tooth; diametral pitch is teeth per inch, and m = 25.4 ÷DP. Gears from the two systems will not mesh.A 20 degree pressure angle is the usual standard. Below aboutseventeen teeth, standard involute teeth undercut.Spur Gear Geometrylearnposters.com
Spur Gear Geometry — printable engineering wall chart from LearnPosters. Free vector PDF, US Letter and A4.

What’s on the Spur Gear Geometry poster

The rule, 3 worked examples, and the mistake everyone makes.

A 20 degree pressure angle is the usual standard. Below about seventeen teeth, standard involute teeth undercut.

Questions about the Spur Gear Geometry poster

What’s on the Spur Gear Geometry poster?
The rule, 3 worked examples, and the mistake everyone makes. Module sets tooth size, and two gears mesh only if they share a module and a pressure…; m = d ÷ z · centres = m(z1 + z2) ÷ 2; m = 2 mm, z = 40 = Pitch diameter 80 mm; z1 = 20, z2 = 60, m = 2 = Centres at 80 mm; Same pair = Ratio 3 to 1; Common mistake: Mixing module with diametral pitch → They are reciprocals in differen…. A 20 degree pressure angle is the usual standard. Below about seventeen teeth, standard involute teeth undercut.
Who is the Spur Gear Geometry poster for?
Spur Gear Geometry belongs to the Mechanical Engineering section rather than to a school year, because engineering is not something one grade owns. Anyone learning machine design can pin it up — a beginner, a student mid-course, or someone revising years later.
When should you use the Spur Gear Geometry poster?
Laying out a gearbox, or checking whether two gears will actually run together. A wall chart earns its place by being glanceable from where the work is happening, so Spur Gear Geometry belongs on the wall where that engineering work actually happens, within glancing distance, rather than filed away.
What other posters go with Spur Gear Geometry?
Bearing Life, Choosing a Bearing and Belt or Chain? sit alongside Spur Gear Geometry in the Mechanical Engineering section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Bearing LifeChoosing a BearingBelt or Chain?
Is the Spur Gear Geometry poster free to download and print?
Yes. Spur Gear Geometry downloads as a free PDF with no account, no email and no watermark, like everything else in the Mechanical Engineering section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
What size does the Spur Gear Geometry poster print at?
Spur Gear Geometry is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of Spur Gear Geometry loses nothing.Printing guide

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