CPM-78-39 Technical Datasheet v1.0¶
Status: Public engineering evaluation reference
Release date: 2026-10-06
CPM-78-39 is a compact 39:1 cycloidal robot joint module with 20 Nm rated output torque and 48 rpm rated output speed.
The values below have been reconciled against the current public product record and a SigGear controlled mechanical drawing supplied for engineering review.
Key Performance¶
| Parameter | Controlled value |
|---|---|
| Transmission structure | Cycloidal pinwheel |
| Outer diameter | 78.7 mm |
| Product thickness | 35.8 mm |
| Reduction ratio | 39:1 |
| Operating voltage | 36 VDC |
| Rated motor power | 200 W |
| Rated output speed | 48 rpm |
| No-load output speed | 54 rpm |
| Rated output torque | 20 Nm |
| Peak output torque | 52 Nm |
| Weight | 600 g |
| Hall angle | 120° |
Warning
Peak torque is not a continuous rating. Peak-torque duration, current limit, duty cycle and thermal suitability must be confirmed for the actual application.
Motor Electrical Parameters¶
| Parameter | Controlled value |
|---|---|
| Phase resistance | 0.225 ohm |
| Phase inductance | 425 uH |
| Maximum phase current | 13 A |
| Rated bus current | 5 A |
| Static working bus current | 0.1 A |
| Motor structure | 24P28N, drawing notation |
| Temperature sensor | MF52B |
| Back-EMF constant | 0.149 Vs/rad |
Standard Configuration Boundary¶
The current standard CPM-78-39 public configuration uses Hall sensors and does not include an integrated driver or absolute encoder as a standard claim.
External driver, encoder, communication interface and closed-loop control solution must be confirmed for the project.
Backlash Data Boundary¶
The public product page currently lists an angular backlash range of 5-10 arcmin.
A separate uploaded laboratory report is titled as a backlash test but reports results in N.m rather than angular units. Because the test method and interpretation are not sufficiently defined for public engineering use, those values are not used here as an angular-backlash verification.
CAD and Drawings¶
A controlled 2D drawing is available for engineering review.
A public STEP model is not currently released in this repository for CPM-78-39.
Request CAD, Drawing or Integration Files
Selection Information Required¶
Please provide:
- Application and joint position
- Rated and peak torque
- Required peak-torque duration
- Required output speed
- Installation envelope
- Duty cycle
- Driver / encoder / communication requirements
- Prototype quantity and estimated annual quantity
Related Pages¶
CPM-78-39 Product Page Custom Cycloidal Transmission Engineering Robot Joint Selection Guide
Engineering Contact¶
Wanrong Wang
International Sales / Sales Engineer, SigGear
wangwanrong@siggear.com