88.0103.253.9
Loading the interactive model…
Interactive 3D model of 4:1 Spur Gearbox v6 (PETG print tolerances)

Gears and transmission

4:1 Spur Gearbox v6 (PETG print tolerances)

1 views
Bounding box
103.2 × 88.0 × 53.9 mm
Engine
Precision B-rep
Parameters
36
Published
November 7, 2026

Download

Free to download and use. See the terms.

The prompt

Precision 4:1 gearbox using 608 bearings, EUDAX 24 mm motor in base pocket, M3 inserts; tolerances tuned for FDM printing in PETG (looser bearing pockets and gear bores, more backlash, tight pinion bore for press fit)

Parameters

NameValueRange
Gear module1 mm0.8 – 2
Pinion teeth1512 – 24
Reduction ratio (x:1)42 – 6
Gear face width8 mm4 – 14
Added centre distance (backlash)0.2 mm0 – 0.6
Output gear/spacer bore clearance0.2 mm0 – 0.4
Pinion bore vs motor shaft (negative = tighter)0 mm-0.1 – 0.3
608 pocket diametral clearance0.2 mm0 – 0.4
608 outer diameter22 mm22 – 22
608 bore / output shaft diameter8 mm8 – 8
608 width7 mm7 – 7
Retaining lip thickness1.2 mm0.8 – 3
Lip hole diameter16 mm12 – 19
Gear to wall gap1.5 mm1 – 4
Shaft end float0.4 mm0 – 0.8
Shaft shoulder / spacer OD11 mm9 – 12
Drive flat depth on output shaft0.6 mm0.3 – 1.2
Output shaft length beyond cover20 mm8 – 50
Motor shaft diameter2 mm1.5 – 4
Motor shaft length beyond face9.7 mm6 – 16
Motor body diameter24 mm12 – 36
Motor body length12.5 mm5 – 60
Motor pocket diametral clearance0.3 mm0 – 0.6
Motor pocket depth6 mm2 – 7
Motor set-screw tap hole (M3)2.5 mm2.2 – 3.2
Pinion lower hub diameter9 mm7 – 11
Pinion hub lift above motor face0.5 mm0.2 – 2
Housing wall thickness10 mm8 – 14
Gear tip to wall clearance3 mm1.5 – 8
Housing corner radius5 mm0 – 8
Base hole for M3 heat-set insert4.2 mm3.8 – 4.6
Insert length (hole depth)5.7 mm4 – 8
Extra depth below insert2.5 mm0.5 – 4
Cover M3 clearance hole3.5 mm3.2 – 3.8
Cover bolt head counterbore diameter6.4 mm5.5 – 8
Cover bolt head counterbore depth3.2 mm2.5 – 4

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.