The RI85-PH KV85 draws less current at its rating (16 A against 20 A), is lighter (411 g against 1108 g), narrower (85 mm against 115 mm) and shallower (27.3 mm against 38.1 mm), and turns faster at the output (3042 RPM against 1430 RPM). The RI115-PH KV40 has more continuous torque (5.5 N·m against 2 N·m) and more peak torque (16 N·m against 5 N·m).
The RI85-PH KV85 is US$166 and the RI115-PH KV40 is US$224. That is US$83.00 per rated N·m for the RI85-PH KV85 and US$40.73 per rated N·m for the RI115-PH KV40.
| RI85-PH KV85 | RI115-PH KV40 | |
|---|---|---|
| Rated Torque (N·m) | 2 | 5.5 |
| Rated Voltage (V) | 48 | 48 |
| Rated Speed (RPM) | 3042 | 1430 |
| No-Load Speed (RPM) | 4080 | 1920 |
| Rated Current (A) | 16 | 20 |
| Phase to Phase Resistance (mΩ) | 138.5 | 134 |
| Phase to Phase Inductance (μH) | 239.4 | 245 |
| OD (mm) | 85 | 115 |
| Weight (g) | 411 | 1108 |
| Peak Torque (N·m) | 5 | 16 |
| Peak Current (A) | 44 (Ref) | 52 (Ref) |
| Height (mm) | 27.3 | 38.1 |
| Inertia (g·cm²) | 652 | 3461 |
| Electrical Time Constant (ms) | 0.0017 | 0.0018 |
| Pole Pairs | 14 | 20 |
Rows the two disagree on are marked; the figures are CubeMars'. To put any other two parts side by side, build your own comparison.