Low cost modifications to Parkzone micro Sukhoi for better aerobatics

The Parkzone micro Sukhoi is a lovely aeroplane. With full 4 channel control it is capable of all classic aerobatics. However out of the box it lacks the thrust and control response for good aerobatic performance. It has poor vertical performance looses too much speed in loop and Immelmans to make it cleanly over the top. So a few mods are in order.

Mod 1: Get the CoG further back

To achieve this without the addition of weight the main RX board with its elevator and rudder servos needs to be moved back from its original position behind the motor. So cut the decals to remove the top cover. Remove the push rods for rudder and elevator. Unplug motor and aileron servo. Carefully remove the RX board by cutting away the foam. Carefully remove most of the remains of foam and glue from the RX board, just enough to ensure the board sits flat and no excess glue sticks out the sides. Using double sided tape mount the RX board to the rear section of the wing as shown in the picture above. Make a hole in the rear of the battery bay for the battery plug to pass through. Extend the motor wires and plug motor and aileron servo back into the RX board. Cut the push rods shorter as required. Remove Z bent wire from discarded ends and fit to end of short push rods with very small bore heat shrink. Offer up push rods adjust position of Z bent wires for best fit and wick a little thin cyano under the heat shrink. Refit push rods, use second hole out from hinge on surface control horn and 30 to 50% exponential on rudder and elevator for good aerobatic response. Test controls for full and free movement, bend wire loop and rear end of push rods as required ensuring controls are central when TX sticks are central. Re-attach cover with some clear fablon patches.

Mod 2: Change the Prop

The original prop just doesn't seem right, it's either under loading the motor or overloading it I can't quite work out which. However a 5 inch diameter 4.5 inch pitch GWS slow fly style prop seems ideal, cheap and light. To mount the prop I drilled down the middle of a nylon screw so that it would self tap onto the gearbox shaft thus providing a prop shaft to mount the prop. However gluing a piece of plastic tube into the hub which could then be screwed onto the shaft would be a little lighter.

With these mods implemented flight was superb with smooth and easy loops and rolls.