Boeing 787 Airliner (Part2)

This is how the EDF is mounted onto the wing.

The 787 is huge and needs lots of extension cables. Certainly, lots of soldering if you keen on not using extension cables.

Towerpro 9g servo do the job well. But it may stand off a bit.

70mm EDF (rear mount). Motor is 3600kv rated 600W. @ 4s x 40A.

The fuselage is separated into 2 sections for easy storage and transfer in car boot ~1.7m !

The tail section, with rudder and elevator wires "Control by wire!"

The front fuselage.

The initial design is a glider version. The turbine case and mount is too weak to hold the thrust. Need reinforcement and lots of epoxy.

The most tricky part is the landing gear and to be continued ..............

Fix Spektrum AR7000 receiver failed initilization

My AR7000 fail to initilize as if the satellite receiver is not connected. Wiring check shows no abnormality. On removing the plastic case (slight damaged after previous crash), the capacitor was found damaged, as well as the satallite receiver connector.

Everthing is fine after replacement of the components.

Repairing Nvidia Forsa 6200 Display Card

Dead Nvidia 6200 display card due to dead fan. 2 capacitor blown and burst. 6.3V 1000uF capacitor is replaced and now works again.

Many P4 system kill the display card like this , because of the unbearable heat from the P4 CPU, especially if there is no good ventilation.

Twin 70mm fiberglass F22

Prepainted fiberglass fuselage, and light foam balsa wing

I put in a brass tube at the elevator attachement to minimize slop.

The initial design for a towerpro90 size mini servo is replaced with a mid-sizr servo. Indeed a metal gear servo is recommended for reliability. The linkage ball and rods are from my Trex500.

Very scale made and perfect painting. The last thing to do is the air-retract system.

Rafale twin 70mmEDF fiberglass fuselage

The twin 70mm EDF was replaced with a single 70mm EDF powered by Hoffmann Magnetics. Average power of 800W @ 4s2p 2200mh Lipo. Will be better with a 3300mAh lipo. The landing gear with shock absorber is a bit too soft, as seen from the bouncy landing.

Stall tendency of Fokker F27 and YS-11

Both Fokker and YS-11 twin propeller has a tendency of stall on take off and yaw turning.
I expereience at last thrice for my Fokker and at least a few buddies in youtube,.

It seems on full throttle take off, especially if there is crosswind, one wing tries to lift while the other wing has not supersede the stall speed. The sinking wing, with its propeller, will fall back into its turbulence and yaw towards itself. This results in a viscious cycle as the higher, outer wing at full throttle will make the inner wing stall further.

Repair Topcon 17" LCD for 10 cents

The circuit board with Genesis GM 5120 chip. Initially I thought this chip is overheated and faulty. But temperature test did not reproduce the problem.



The burnt SMD reistor is replaced with a 0.5W 1k resistor.


The burnt resistor.


High voltage circuit on the right. Control circuit at the center.

This is the worst LCD with poor quality control I ever have. It starts showing abnormal green lines over white area randomly after powering on for 30-60 mins. Since it is bought for over 6 months, it was sent to the repair centre for checking. After sending to the customer services for 3 times over 3 months, they still claim the LCD has no problem. The problem gets worst and worst and becoming completelty white screen after 3 hours operation.

Opening up the circuit board with careful inspection, on of the capacitor show some buldging, yet no leaking. A 10k resistor near a transistor seems blown off.

The SMD 103 10k resistor was fixed with a larger one, but it works. Testing for 48 hours show that the operation is successful.