Full specification
| Parameter | Value |
|---|---|
| Frame | Φ98 × 61.7 mm |
| Ratio | 9:1 · planetary |
| Rated torque | 20 N·m |
| Peak torque | 40 N·m |
| Weight | 896 g · 963 g for the P variant |
| Supply | 24 V nominal · 24–48 V supported |
| Encoder | Dual encoder (2EC) · single-turn absolute on the output side |
| Comms | CAN / CAN FD |
| Brake | None |
| Torque sensor | None |
Source: DAMIAO 2026 product selection catalogue, DM-J planetary series. Figures verified November 2026 — confirm the exact variant against the datasheet issued with your order.
When this is the right choice
- Wheel and traction drives. 9:1 gives ground speed that a 48:1 frame cannot reach at the same motor speed.
- 20 N·m continuous at under a kilogram. Enough for a small mobile base or a fast positioning axis.
- Backdrivable enough to be pushed by hand when unpowered, which is useful during commissioning.
- Absolute output position, no homing sequence on start-up.
When it is the wrong choice
- Gravity-loaded axes. 9:1 backdrives under load and there is no brake — an arm axis will sag.
- Precision reversal. Planetary backlash, not a wrist joint.
- Needing 50 N·m. DM-J8520P sits there at 1,392 g.
Alternatives at a similar level
- DAMIAO DM-J8520P — 50 N·m rated, 176 N·m peak, 1,392 g
- DAMIAO DM-J8006 — Flat 8 N·m frame for plate-mounted turntables
- DAMIAO DM-J6248P — 30 N·m at 48:1, 660 g — more holding, less speed
- Crabnova CE-RBV3-R68-101 — 33–82 N·m with brake and sensor when precision matters
Quote this model
Model, quantity and destination is enough to start — we come back with price, availability and the datasheet.
DM-J8009 FAQ
Why a 9:1 joint in a humanoid parts catalogue?
Because half of what people build is not a humanoid arm: wheeled bases, turntables and fast positioning axes need a low ratio and a high output speed.
Can it hold a stationary position?
Only with the motor energised. At power-off a 9:1 planetary backdrives easily — there is no brake.
P or non-P?
Same torque, different output interface, 67 g heavier for P. Match the mating part.
How long does it take to ship?
Confirmed per order at quotation.
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