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Interactive 3D model of Herringbone Gearbox 9.4:1 (608 + 683 bearings)

Gears and transmission

Herringbone Gearbox 9.4:1 (608 + 683 bearings)

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Bounding box
88.7 × 97.7 × 93.0 mm
Engine
Precision B-rep
Parameters
27
Published
November 8, 2026

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The prompt

3D-printed two-stage herringbone gearbox (about 9.4:1) using 608 and 683 bearings and 1 mm, 3 mm and 8 mm rod: input shaft (3 mm) and output shaft (8 mm) each supported at both ends, a 3 mm countershaft, smooth balanced herringbone gears with no axial thrust and axisymmetric lightening, hunting-tooth ratios, 0.2 mm backlash, axial float and a housing whose bearing seats are all printed in two parts located by dowels so nothing binds

Parameters

NameValueRange
Gear module1 mm0.8 – 1.5
Pinion teeth (both stages)1614 – 22
Gear teeth (both stages; keep it coprime with the pinion for even wear)4936 – 64
Helix angle of each half of the herringbone25 deg15 – 35
Gear face width (both halves together)12 mm8 – 16
Added centre distance (backlash)0.2 mm0.1 – 0.4
Web thickness of the big gears (lightening, symmetric so they stay balanced)3 mm2 – 6
Rim thickness under the teeth of the big gears4 mm3 – 6
Angle at the countershaft between input and output shaft (180 would be in a line)90 deg80 – 150
Housing wall thickness4 mm3 – 8
Gear tip to housing wall3 mm2 – 6
Gap between the two gear layers2 mm1.5 – 4
Gap between the gears and the bearing faces (spacer length)2 mm1.5 – 4
683 bearings stacked at each end of the 3 mm shafts (1 or 2)21 – 2
Bearing pocket diametral clearance0.15 mm0.05 – 0.3
Gear and spacer bore clearance on the shafts (diametral)0.15 mm0.05 – 0.3
Axial end float of every shaft (lets herringbone gears centre themselves)0.4 mm0.2 – 0.8
Input shaft length sticking out of the bottom20 mm10 – 40
Output shaft length sticking out of the top25 mm10 – 50
Drive flat depth on the 3 mm shafts0.4 mm0.2 – 0.8
Drive flat depth on the 8 mm shaft0.6 mm0.3 – 1.2
Hole for M3 heat-set insert4.2 mm3.8 – 4.6
Insert length (hole depth)5.7 mm4 – 8
Extra depth below the insert2.5 mm0.5 – 4
M3 clearance hole3.5 mm3.2 – 3.8
Bolt head counterbore diameter6.4 mm5.5 – 8
Bolt head counterbore depth3.2 mm2.5 – 3.5

Every value above is a live dimension. Open a model like this in the editor and each one becomes a slider you can drag before exporting.