Stall torque
Part A2.746 Nm
Part B4.511 Nm1.765 Nm higher
Part comparison
Blue Bird BMS-28A vs KST X20-4208
A side-by-side comparison of source-backed specifications within the same subcategory.
11 shared specs3 scored
Directional spec summary
Counts across 3 numeric specifications with a clear higher-or-lower direction.
Part A leads
0
Tied
0
Part B leads
3
These are metric-by-metric differences, not an overall performance score. Check the values below.
Specifications
11 specifications compared side by side.
| Compare bySpecification | ABlue BirdBlue Bird BMS-28A | BKSTKST X20-4208 |
|---|---|---|
| Performance3 | ||
| Stall torque | 2.746 Nm | 4.511 Nm1.765 Nm higher |
| Stall torque @ 7.4V | 28 kg·cm | 46 kg·cm18 kg·cm higher |
| Speed @ 7.4V | 0.1 s/60° | 0.07 s/60°0.03 s/60° lower |
| Mechanical & integration4 | ||
| Motor kind | Rc servo | Rc servo |
| Drive principle | servo actuator | servo actuator |
| Architecture | Integrated servo module | Integrated servo module |
| Gear material | metal | metal |
| Control & communication3 | ||
| Communication interfaces | PWM | PWM |
| Control modes | PWM servo | PWM servo |
| Servo signal | PWM | PWM |
| Other specifications1 | ||
| PWM pulse center | 1500 µs | 1500 µs |
ABlue BirdBlue Bird BMS-28A
BKSTKST X20-4208
Performance3
Stall torque @ 7.4V
Part A28 kg·cm
Part B46 kg·cm18 kg·cm higher
Speed @ 7.4V
Part A0.1 s/60°
Part B0.07 s/60°0.03 s/60° lower
Mechanical & integration4
Motor kind
Part ARc servo
Part BRc servo
Drive principle
Part Aservo actuator
Part Bservo actuator
Architecture
Part AIntegrated servo module
Part BIntegrated servo module
Gear material
Part Ametal
Part Bmetal
Control & communication3
Communication interfaces
Part APWM
Part BPWM
Control modes
Part APWM servo
Part BPWM servo
Servo signal
Part APWM
Part BPWM
Other specifications1
PWM pulse center
Part A1500 µs
Part B1500 µs
Product sources
Product sources used by this comparison
Blue Bird BMS-28AOpen source ↗
KST X20-4208Open source ↗