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Grooved (wedge) friction gearing, 30 : 60

Why are friction wheels grooved? · Hardware · basis: Xem Studio design following Brown No. 45 (1868)

Also called: grooved friction wheel, wedge friction drive, v groove friction gearing, engranaje de fricción ranurado, Keilreibradgetriebe

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

sizes
4 in table

Notes

  • Ridges on one wheel wedge into matching V-grooves on the other: pressed together with force F, the normal force on the flanks is F / sin(α/2), so with 67.38° grooves the grip is about 1.8 times that of plain wheels at the same pressure.
  • Ratio by pitch diameters, 60/30 = 2 : 1, centres 45 mm; the two profiles are exact complements on the line of centres (touching flanks, no overlap).
  • Brown's No. 45 (friction gearing with grooves, shown in section).
  • Parts (each has its own page): grooved-friction-wheel-30, grooved-friction-wheel-60.
  • Brown's movement No. 45 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

Grooved (wedge) friction gearing, 30 : 60 size chart

parametervalue
wheelspitch Ø30 and Ø60 × 16
grooves4 mm pitch, 67.38°
centres45 mm
grip gain≈ 1.8×

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. 45: figure, his text and an animationwebPublisher's page; dimensions are facts

Free files

★ Free files 1 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json

grooved-friction-wheels-mechanism-assemblyAssembled mechanism, all parts placed at one pose (STEP keeps each part separate)STEP · 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=grooved-friction-wheels-mechanism

Grooved (wedge) friction gearing, 30 : 60, isometric render of a generated part
Render of grooved-friction-wheels-mechanism-assembly from the free STEP; not to scale.

Fits with

Grooved friction wheel, pitch Ø30, 4 mm V-grooves × 16 wide, isometric render of a generated part
Grooved friction wheel, pitch Ø30, 4 mm V-grooves × 16 wide33.0×33.0×16.0 mm★ 1 file
Grooved friction wheel, pitch Ø60, 4 mm V-grooves × 16 wide, isometric render of a generated part
Grooved friction wheel, pitch Ø60, 4 mm V-grooves × 16 wide63.0×63.0×16.0 mm★ 1 file

Questions

Why are friction wheels grooved?

Ridges on one wheel wedge into matching V-grooves on the other: pressed together with force F, the normal force on the flanks is F / sin(α/2), so with 67.38° grooves the grip is about 1.8 times that of plain wheels at the same pressure.