Print-in-place: planetary gearbox, herringbone, 4 : 1

length

112.0 mm

width

112.0 mm

height

48.0 mm

Notes

• 3D print in place — prints already assembled, moving, in one job. Drawn at true size with no printer tolerance added; the 0.40 mm running gaps are part of the design.
• Running gap 0.40 mm per side, 0.80 mm on diameter — part of the design, drawn as is. On the 45° faces the same 0.40 mm is measured square to the face (0.57 mm along the axis).
• Bed: sun, three planets, ring and carrier all stand on the bed: the gears on their bottom faces, the carrier on its three pins (each a 45° cone in a planet's counterbore). The carrier grows up from the pins as three 45° cones that merge into one three-lobed dome above the gears.
• Support while printing: herringbone flanks lean 28° (base helix) and the carrier's underside is all 45° cone, 0.40 mm clear of the planet tops and bores; the sun's knob flares out at 45° above the carrier. Nothing is flat over air.
• Captured: the herringbone (two opposed 30° helices) locks each planet axially between sun and ring; each planet's 45° counterbore holds the carrier's pin base below it; the carrier's cones close over the planets above. Nothing can come out.
• Freeing it: hold the ring and turn the sun knob slowly in both directions until it runs smoothly (a screwdriver fits the slot); the carrier follows at a quarter of the speed.
• Motion: continuous; ratio 4 : 1 (sun : carrier, ring fixed); planets spin 1× the sun-relative-to-carrier speed. Checked in the transverse section through a quarter turn of the sun: min gap 0.454 mm in the section (≥ 0.40 square to the flanks).
• Involute teeth: 20° normal pressure angle, addendum 1.0 m, dedendum 1.25 m (ring: tips at 0.88 m inside the pitch circle, the catalog ring's rule); every tooth thinned so the running gap is 0.40 mm square to the flanks at the exact centre distance.

Print-in-place: planetary gearbox, herringbone, 4 : 1 size chart

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Free files

★ Free files 7 parts. Xem Studio design: free to use, print and sell things from; not to be republished as files. Xem Studio Design License. index.json

Plain text: sheet.txt · JSON: /api/geometry?object=print-in-place-planetary-gearbox

Fits with

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