Xem Studiomeasured geometry

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Rod fed between two skewed rollers (screw-like feed)

How do skewed rollers feed a rod? · Hardware · basis: Xem Studio design following Brown No. 365 (1868)

Also called: skew roller feed, oblique rollers, roller screw principle, rod feeder, rodillos oblicuos, Schrägrollenvorschub

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

sizes
5 in table

Notes

  • A round rod is gripped between two rollers whose axes are set at ±15° to the perpendicular instead of parallel. Each roller's rim speed splits into a component along the rod (feed) and one across it (rotation), so the rod both advances and turns, like a screw with no thread.
  • Per roller turn: advance π·D·sin α = 24.39 mm and rotation D·cos α / d = 2.9 turns of the Ø10 rod (Ø30 rollers). Drawn with the rollers touching the rod (point contact) on Ø5 axles; the skew angle sets the pitch.
  • Brown's No. 365 (rollers with oblique axes); the principle of roller screws, wire straighteners and bar feeders.
  • Parts (each has its own page): feed-roller-d30x20-b5, linear-shafts-h6, dowel-pins-metric.
  • Brown's movement No. 365 (1868) shows it; this model is a Xem Studio design following his figure, every part at true size.

Rod fed between two skewed rollers size chart

parametervalue
rodØ10 × 100 (linear shaft)
rollers2 × Ø30 × 20
skew angle±15°
feed per roller turn24.39 mm
rod turns per roller turn2.9

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. 365: figure, his text and an animationwebPublisher'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

skew-roller-feed-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=skew-roller-feed-mechanism

Rod fed between two skewed rollers (screw-like feed), isometric render of a generated part
Render of skew-roller-feed-mechanism-assembly from the free STEP; not to scale.

Fits with

Feed roller Ø30 × 20, Ø5 bore, isometric render of a generated part
Feed roller Ø30 × 20, Ø5 bore30.0×30.0×20.0 mm★ 1 file
Linear shafts Ø3 to Ø25 mm (h6), 100 to 1000 mm long, isometric render of a generated part
Linear shafts Ø3 to Ø25 mm (h6), 100 to 1000 mm long10 sizes★ 70 files
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 do skewed rollers feed a rod?

A round rod is gripped between two rollers whose axes are set at ±15° to the perpendicular instead of parallel. Each roller's rim speed splits into a component along the rod (feed) and one across it (rotation), so the rod both advances and turns, like a screw with no thread.