Up for sale is a set of four rebuilt JR PROPO F8911FOC servos originally prepared for the Joe Nall Week event.
These servos have been professionally rebuilt using a combination of new internal components and carefully inspected original cases.
Rebuild Details
Brand new motor
Brand new gear set
Brand new PCB/electronics
Original center/middle case reused
Some outer case components may show minor cosmetic wear from previous use
The reused metal cases are genuine original parts and are fully functional, but they are not cosmetically brand new. Because of this, slight scratches, marks, or signs of previous installation may be visible.
Each servo has been rebuilt, tested, and confirmed to operate properly.
Included
4 × JR PROPO F8911FOC Rebuilt Servos
Notes
Intended for experienced RC users and competition pilots
Performance-related internal components are new
Cosmetic condition may vary slightly due to reused case parts
Limited quantity available
 
What Is an FOC (Field-Oriented Control) Servo?
 
・Extremely smooth operation
Unlike conventional servos, FOC control significantly reduces torque ripple, resulting in exceptionally smooth movement.
・Highly efficient control reduces unnecessary power consumption
FOC offers superior voltage utilization, minimizing wasted current and efficiently converting power into torque.
・High torque across the entire operating range
Thanks to efficient voltage usage, the motor delivers consistent and uniform torque at all positions.
・Fully customizable performance to match your setup
Operating characteristics can be optimized by adjusting parameters to suit different control surface loads and arm lengths.
・Audible beep notification during communication and XBUS setting changes
A beep sound confirms communication startup after receiver power-on and notifies you when XBUS parameters are changed.
・Reduced hunting behavior
By detecting the rotor position (angle) through FOC control, hunting is significantly minimized.
 
・XBUS programmable servo
・The gears are carborized gears, making them even more durable!
・BIG upper ball bearing (12x6) bottom(10x6)
・Neutral: 1500 µSec / 760 µSec (Auto)
・Operating Voltage: 5.5V – 8.4V
・Weight: 79 g (2.79 oz)
 
[Stall Torque]   
52.6kgs  (6.6V) / 59.0kgs  (7.4V) / 67.0kgs (8.4V)kg・cm
731.1oz (6.6V) / 819.7oz (7.4V) / 930.5oz (8.4V)oz・in
[Speed]
0.15 (6.6V)/0.13 (7.4V)/0.11 (8.4V) Sec/60°
[diemension]
35 x 20 x 40.5 mm / 1.38 x 0.79x 1.59 in
 
The FOC servo can be programmed just like a 2K servo, but certain parameters are now automatically adjusted, eliminating the need for programming.
[List of Programmable Settings]