The AKE40-6 KV90 has a higher torque constant (0.12 N·m/A against 0.104 N·m/A), draws less current at its rating (2.5 A against 3 A), is lighter (140 g against 190 g) and narrower (51 mm against 61.2 mm), and turns faster at the output (260 RPM against 240 RPM). The AKE50-8 KV110 has more continuous torque (2.5 N·m against 1.8 N·m) and more peak torque (7.5 N·m against 5.5 N·m), and is shallower (22.5 mm against 24.5 mm).
The AKE40-6 KV90 is US$134 and the AKE50-8 KV110 is US$190. That is US$74.44 per rated N·m for the AKE40-6 KV90 and US$76.00 per rated N·m for the AKE50-8 KV110.
| AKE40-6 KV90 | AKE50-8 KV110 | |
|---|---|---|
| Reduction Ratio | 6:1 | 8:1 |
| Rated Torque (N·m) | 1.8 | 2.5 |
| OD (mm) | 51 | 61.2 |
| Weight (g) | 140 | 190 |
| Peak Torque (N·m) | 5.5 | 7.5 |
| Rated Voltage (V) | 24 | 24 |
| Rated Speed (RPM) | 260 | 240 |
| No-Load Speed (RPM) | 330 | 320 |
| Rated Current (A) | 2.5 | 3 |
| Peak Current (A) | 8 | 9 |
| Maximum Torque Weight Ratio (N·m/kg) | 39.3 | 39.5 |
| Height (mm) | 24.5 | 22.5 |
| Max Continuous Power (W) | 50 | 65 |
| Backlash (arcmin) | 9 | 9 |
| Backdrivable Torque (N·m) | 0.05 | 0.09 |
| Rotor Inertia (g·cm²) | 188.78 | 153.81 |
| Motor Constant (N·m/√W) | 0.082 | 0.097 |
| Kv (RPM/V) | 90 | 110 |
| Kt (N·m/A) | 0.12 | 0.104 |
| Ke (V/kRPM) | 11.1 | 7 |
| Phase Resistance (mΩ) | 1660 | 792 |
| Phase Inductance (μH) | 950 | 560 |
| Pole Pairs | 14 | 14 |
| Number of Slots | 24 | 24 |
| Basic Dynamic Load Rating Cr (N) | 1040 | 1100 |
| Basic Static Load Rating C0r (N) | 730 | 840 |
| Noise dB (65cm away the motor) | 65 | 65 |
| Operation Ambient Temperature | -20℃~50℃ | -20℃~50℃ |
| Insulation Level | F | F |
| Dielectric Strength | 500V | 500V |
| Insulation Resistance | 500V 10MΩ | 500V 10MΩ |
| Driving Way | FOC | FOC |
| Application | Exoskeleton, Robotic Arm | Exoskeleton, Robotic Arm |
Rows the two disagree on are marked; the figures are CubeMars'. To put any other two parts side by side, build your own comparison.