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Grooved heart cam (face cam) with roller follower

Why put a cam groove in the face of a disc? · Hardware · basis: Xem Studio design following Brown No. 97 (1868)

Also called: grooved cam, face cam, positive cam, heart cam groove, leva de corazón ranurada, Herznutkurve mit Rolle

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

sizes
4 in table

Notes

  • A groove cut in the face of a disc holds the follower's roller between two walls, so the cam drives it both out and back (positive drive, no return spring). The heart-shaped centre line gives uniform speed: 20 mm out over half a turn, 20 mm back.
  • Drawn at 60°: roller centre 26.67 mm from the axis, touching one wall (contact only).
  • Brown's No. 97 (grooved heart cam, a variant of No. 96).
  • Parts (each has its own page): grooved-heart-cam-r20-h20, roller-follower-10, cam-follower-bar-roller-pin, dowel-pins-metric.
  • Brown's movement No. 97 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

Grooved heart cam (face cam) with roller follower size chart

parametervalue
groove centre lineR20 → R40 → R20
rollerØ10 × 4 (roller-follower-10)
stroke20 mm
motionuniform velocity

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. 97: 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-heart-cam-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-heart-cam-mechanism

Grooved heart cam (face cam) with roller follower, isometric render of a generated part
Render of grooved-heart-cam-mechanism-assembly from the free STEP; not to scale.

Fits with

Grooved heart cam (face cam), uniform motion, 20 mm stroke, isometric render of a generated part
Grooved heart cam (face cam), uniform motion, 20 mm stroke102.0×102.0×10.0 mm★ 1 file
Roller follower Ø10 on a Ø3 pin, isometric render of a generated part
Roller follower Ø10 on a Ø3 pin2 sizes★ 1 file
Follower bar 8 × 5 with Ø3 roller pin hole (75 mm), isometric render of a generated part
Follower bar 8 × 5 with Ø3 roller pin hole (75 mm)10.0×80.0×5.0 mm★ 1 file
Dowel pins, 2–6 mm (ISO 2338 / DIN 6325), isometric render of a generated part
Dowel pins, 2–6 mm (ISO 2338 / DIN 6325)5 sizes★ 23 files

Questions

Why put a cam groove in the face of a disc?

A groove cut in the face of a disc holds the follower's roller between two walls, so the cam drives it both out and back (positive drive, no return spring). The heart-shaped centre line gives uniform speed: 20 mm out over half a turn, 20 mm back.