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Barrel (cylindrical) cam with pin follower

How does a barrel cam make reciprocating motion? · Hardware · basis: Xem Studio drawing; classic mechanism (Brown No. 106)

Also called: barrel cam, cylindrical cam, groove cam, drum cam, leva cilíndrica, came cilíndrica, Trommelkurve, came cylindrique

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

sizes
3 in table

Notes

  • A groove cut round a cylinder carries a follower pin: one turn moves the pin along the axis by the groove's rise and back. Here a sine groove gives 15 mm of simple-harmonic stroke.
  • Groove shape sets the motion: a helix reversed at the ends gives uniform speed (Brown's grooved cylinder), a sine gives smooth harmonic motion.
  • Used in sewing machines, fishing reels' level wind and indexing tables.
  • Parts (each has its own page): barrel-cam-r20-h15, dowel-pins-metric. Brown's movement No. 106 shows it (1868).

Barrel (cylindrical) cam with pin follower size chart

parametervalue
cylinderØ40 × 50 mm
stroke15 mm
groove width6.4 mm (Ø6 pin)

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

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

barrel-cam-mechanism-assemblyAssembled mechanism, all parts placed (STEP keeps each part separate)STEP · STL
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Plain text: sheet.txt · JSON: /api/geometry?object=barrel-cam-mechanism

Barrel (cylindrical) cam with pin follower, isometric render of a generated part
Render of barrel-cam-mechanism-assembly from the free STEP; not to scale.

Fits with

Barrel (cylindrical) cam Ø40, 15 mm stroke, isometric render of a generated part
Barrel (cylindrical) cam Ø40, 15 mm stroke3 sizes★ 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

How does a barrel cam make reciprocating motion?

A groove cut round a cylinder carries a follower pin: one turn moves the pin along the axis by the groove's rise and back. Here a sine groove gives 15 mm of simple-harmonic stroke.