A monoplane fighter ahead of its time?

With the U/C in place the painting can get under way.

In hind sight dark green on white Depron was far from ideal. It still shows streaks after two coats. About the only saving grace is a crude streaky two colour finish was not unknown indeed Fokker used as a factory finish. It was so crude that it was one of the reasons why the 'aces' insisted on having their planes repainted in their own colours.

The orange in the Dutch markings has come out almost pink! :woohoo:
One of the 6 tiny eyelets that will be used to change the direction of the cable in the aileron/rudder pull/pull system.

By comparison the elevator pull/pull is simple and direct.

Nearly there!

Part of the aileron closed loop circuit.

The line from the aileron passes through the tube to the other side of the fuselage before turning back to the rudder.
The underside line goes directly to the servo arm under the centre of the wing.

By comparison the elevator loop is simple and direct.

The whole ensemble driven by a servo tester.

It will maiden with the 7x4 rather than the scale diam 8x4.3 as I don't really need the thrust and the torque will be less.

As I am having trouble with the Orange 2.4 I have installed a 35mHz Corona 4ch as it is plenty small enough.
So it now has a long aerial trailing out the back but it is flight ready although the weather is not!
A video of a short taxi under its own power.

It has masses of power indeed it looks like it might have a very non scale unlimited vertical.

It does fly but.........
I fear the length of the pull/pull line for the combined aileron/rudder is just too long with the result the roll control is nothing, nothing and then everything! :woohoo: . On a small light low wing plane this is not ideal! :ohmy:
After 4 short flights the U/C was bent, the cowling dented, the wing tip creased and the prop broken.
So
The rudder has been temporarily fixed and resulting shorter aileron pull/pull line has been replaced with line of treble the stretch stiffness.
The U/C has been straitened and for the time being the undercarriage wing removed.

The cowling is repaired.

It may be calm enough by the weekend to have another go and as soon as it flies half way decently I will video it.

A rather poor video of the V25 with the new aileron system struggling against a wind almost equal to its flying speed and coupled with a CofG that is probably a bit too far back.

The flight was terminated before it got any further down wind! It was undamaged.
The 2:45 flight only used 1/5 the capacity of the 800mAh 2s battery.

The question is can I move the CofG forward without having to cut open the fuselage to gain access.

Put a couple of steel washers behind the prop, on the motor shaft?

Eric wrote: Put a couple of steel washers behind the prop, on the motor shaft?

A lead spinner helps too......but any rotating weight will lead to some gyroscopic precession which might make controlling it even more fun.

Especially if it's out of balance.

Of course I could weight each of the nine cylinders and create some serious gyroscopic forces - just like the real thing! :lol:

So far I have moved the radio forward from it position in line with the wing trailing edge to close behind the firewall. Its only light but "every little helps".

As I feared moving the radio made little difference so there is only the battery left!
At the present it is right up against the firewall but long wise on placing its CofG 1" back.
By mounting the battery 'vertically' its CofG will be 1/2" back.and as it represents 25% of the all up weight it should make a difference.

The CofG of the plane is now close to 25%
The battery connection is still made from within the cockpit.
When some suitably calm weather arrives I will try it like this before building a proper hatch.

Calm this morning.
It certainly flies better but still pretty twitchy.

The biggest issue is the substantial prop torque on the light airframe which make the ailerons not only power sensitive but also a huge difference in response between left and right.
In the video it loops well enough but torque rolls at the top and neatly pulls out with a 90 degree change in heading.

Being so small it has to be flown really close to the camera to get a decent video. As soon as the motor mounting is repaired I will try again.

The Fokker has flown quite a bit but the repeated nose over landing on the long wet grass have taken their toll.
First the rotary 'let go' on a full power test. (the paper cylinders don't like getting wet!). Only one cylinder broke free but being dragged round inside the cowl dislodged them all and the prop wash 'distributed' them all over the room! Not too difficult to build another.
Second the firewall (Its Depron) slowly got weakened and became rather too flexible resulting in serious motor vibration at critical revs.
You can hear it in this mornings video and towards the end it got noticeably worse so the flight was terminated before the whole nose got torn away.

The solution is to remove the old firewall

and replace it with a balsa version.

It is made up of 4 plies of 1mm balsa with the motor mount sandwiched between layers 1 and 3.

Just got to put it all back together.

A new rotary.

The cylinders are now solid Depron and are not only glued to the bell but also together so it can be run safely at full speed even without a prop.
All put back together.



Just need some suitable weather.

It still flies. Some aerobatics.

I am seriously thinking about building a bigger version.