The Walkera 4#3B helicopter flies very well with the brushed main motor, but as with any brushed motors, their lifespan is very short compared to brushless motors. I took the next step and bought the Walkera 4#3B brushless upgrade kit from Walkera. Walkera really made the upgrade kit easy to install into older brushed Walkera 4#3B helicopters. Included in the kit are the Kv11000 brushless main motor, speed controller, receiver and brushed tail motor.

You cannot use the receiver that came with the brushed Walkera 4#3B helicopter, as there is no throttle jack for the speed controller. That is why Walkera includes a new receiver with a throttle jack . Don’t be concerned, the new receiver included in the upgrade kit will work with your old transmitter that came with the brushed Walkera 4#3B. The tail motor that is included in the kit is more powerful than the tail motor that came with the brushed Walkera 4#3B, so it need to be replaced.

After you have removed the brushed main motor, you need to cut a small section out of the main frame so that the brushless motor can fit. If not, the metal pinion gear on the brushless motor won’t mesh correctly with the main gear. Use the supplied screws to secure the brushless motor, and make sure that the gears don’t mesh to tight. Don’t pull on the tail motor and servo leads when removing them from the old receiver. You might just pull the pins out the connectors. Remove the old receiver and old double side tape from the receiver tray.

The new receiver needs to be installed the same way around as the old receiver. Connect the tail motor, elevator and aileron servo connectors as per outer cover on the receiver. Connect the speed controller to the throttle channel on the receiver. Use the supplied double-sided tape for the speed controller to secure it below the receiver. The brushless motor connector leads on the speed controller need to be facing forward.

Connect the speed controller to the brushless motor. The second LiPo battery connector on the receiver is only used if you run a brushed main motor. With this brushless conversion, you will only use the LiPo connector on the speed controller to supply power to the helicopter. Make sure that the canopy fits without putting to much strain on the canopy nuts. Now that the installation is complete, everything need to be tested before your first flight.

Make sure that the rudder trim tap is set in the middle, and the throttle in the closed position. Switch the transmitter on and connect the LiPo battery to the speed controller. Don’t touch the controllers on the transmitter until the gyro has finished initializing. Wait for a steady red light on the receiver and transmitter. Move the elevator and aileron controls on the transmitter. If you move the elevator on the transmitter and the aileron servo moves on the helicopter, you need to switch the aileron and elevator connectors on the receiver.

Slowly advance the throttle on the transmitter to check if the brushless motor is running. If the main rotor blades are spinning in the wrong direction, you need to turn the plug around that connects the speed controller to the brushless motor. The tail motor should start turning as soon as the throttle is advanced and respond to rudder inputs. Make sure that the gyro is working by twisting the helicopter right and left in your hand while the throttle is set at about 30%. The tail rotor should respond by increasing in rpm when twisted counter clockwise, and decrease in rpm when twisted clockwise. Now that every thing is working, you are ready for the first flight.

Keep in mind that the helicopter is a bit nose heavy with the brushless upgrade, and up elevator trim should be added for a steady hover. The gyro sensitivity can be adjusted on the receiver if needed. There is no servo extend adjustment on this receiver, so for more swash movement, you need to move the servo linkage ball to the outer hole on the servo arm.
 

I’m glad that I have upgraded my Walkera 4#3B to brushless. Overall the helicopter flies more stable due to increased weight, and the vertical climb performance is better with the powerful brushless motor. I would recommend the Walkera 4#3B brushless kit to anyone that is still flying with the brushed motor.