42P Planetary Gearbox Mechanical Interface v1.1¶
Status: Public engineering evaluation reference
Release date: 2026-10-08
Controlled drawing code: SG01PD42
This page summarizes the mechanical-interface information that is suitable for public early evaluation from the current SigGear controlled 2D drawing.
Warning
This page is not a manufacturing drawing. Use the current controlled drawing for final tolerances, detailed shaft geometry and production design release.
Controlled Envelope¶
| Item | Controlled / published reference |
|---|---|
| Nominal gearbox body diameter | Ø42.0 mm (0 / -0.1 mm shown on drawing) |
| Gearbox body length | L ±0.3 mm, stage-dependent |
| Output-side extension | 29.5 mm (+0.1 / -0.3 mm) |
| Output shaft diameter | Ø12.0 mm (0 / -0.02 mm) |
| Output-side locating / reference diameter | Ø28.0 mm (0 / -0.03 mm) |
| Output keyway | DIN 6885-A4×4×20 |
| Keyway length | 20.0 mm |
| Output-side mounting | 4 × M4 threaded holes, depth 6 mm |
| Output-side reference diameter | Ø35.0 ±0.1 mm |
| Input-side center opening | Ø16.0 mm (+0.05 / 0 mm) |
| Input-side mounting | 2 × Ø3.1 mm holes |
| Opposed input mounting-hole spacing | 25.0 ±0.1 mm |
Stage-Dependent Length¶
The controlled drawing uses L for the gearbox body length with ±0.3 mm shown on the drawing. L changes with the selected stage count.
| Stages | Gearbox body length L |
|---|---|
| 1 | 35.6 mm |
| 2 | 46.9 mm |
| 3 | 58.2 mm |
| 4 | 69.5 mm |
Use the selected stage / ratio and the controlled drawing revision before final production release.
Published Mechanical Limits¶
| Item | Public value |
|---|---|
| Radial load, 10 mm from flange | ≤ 16.0 kgf |
| Shaft axial load | ≤ 8.0 kgf |
| Radial shaft play | ≤ 0.04 mm |
| Thrust shaft play | ≤ 0.3 mm |
| Continuous permissible input speed | ≤ 8,000 rpm |
| Operating temperature range | −40 to 120 °C |
These limits come from the current 42P specification sheet and should be checked against the actual application load direction, duty cycle and selected configuration.
Public Simplified CAD¶
Download 42P Simplified STEP - 4-Stage Reference
The released public STEP is a single-solid simplified external-interface model for early packaging and mechanical Design-In. It represents the 4-stage reference configuration only and intentionally omits the internal planetary transmission construction.
A detailed full-assembly 42P STEP is still retained as configuration-controlled engineering CAD and is not published as a raw download.
For another stage count or final production release, request the configuration-matched controlled CAD / drawing.
Request 42P Controlled CAD / Drawing
Open 42P Motor Integration Guide
Design-In Boundary¶
Before final design freeze, confirm:
- Stage count and reduction ratio
- Exact gearbox body length L
- Output shaft / mounting interface
- Motor-side pilot and shaft interface
- Motor speed and torque operating point
- Radial / axial load condition where relevant
- Configuration-specific CAD revision
Engineering Contact¶
Wanrong Wang
International Sales / Sales Engineer, SigGear
wangwanrong@siggear.com