Hi guys
I know this is a bit behind, we get used to that in the UK, but I finally got round to finishing my Wildhare Giles 202 - 35% (only took 15months) and test flew it yesterday - when the weather finally improved!!!!
Despite issues with the engine being very rich (ZDZ 80) as it is new, the plane was still very impressive, very precise with no coupling to knife edge what so ever!!!!!!
Balancing the plane the night before I thought a rearward C of G may be a problem but as it turns out it was about 1/2" infront of the wing tube. Landing was fine not too quick and when pulled to 45 deg and rolled inverted it only gently began to pull to the canopy.

When the stall was tested it felt a bit snappy and holding in elevatorinduced a gentle spin - This was confirmed when 'harriers' were attempted - kept in a straight line it seemed ok as soon as a turn was initiated it was VERY difficult to stop it snapping.

Another thing is that I am running a three blade prop 10" pitch, just to keep the noise down really - but I thought coming in on an overshoot that when I throttled up the plane yawed????? Does anyone have any info on three blade props .....never used them before. In the vertical it gently pulls off to the left - Is this another result of the prop. Would changing to a 2 blade solve some of this????

There's a couple of issues here all help will be appreciated - need to get it dialed in soon as IMAC season is coming up!!!

Many Thanks

Phil

It sounds to me like you may have to much elevator throw and that is causing the plane to want to spin. Also it sounds as if you need a little right thrust.

I have one of the 35% Giles, as well as the 40%.

The c/g is forward of where it should be. Where you have it works, but makes for a snappier plane. Center of wing tube works a lot better. The forward edge of the wing tube is about as far forward as you should have it. BTW, the cause of any real spin is a stall. A plane will not spin unless it has been stalled first.

All planes yaw with an increase in power. It's called "P" factor and torque. You also have a thing called a "spiraling slipstream" . All of this is caused by the propeller and the engine. If you also had a rudder on the bottom of the plane the issue would go away. If your propeller was to rotate to the right instead of the leaft the yaw would be the other direction from what it is now.

An example of how power levels, torque, and yaw effects a plane was observed this past weekend. A 46% Ultimate at full throttle in a knife edge pass had almost no pitch coupling and flew a nice straight pass. When the throttle was reduced the plane would complete a perfect knife edge circle to the belly without any change in rudder or elevator input. So to answer to your question about if changing power levels could change the amount of yaw, the answer is most definately yes. It also effects other factors, such as pitch coupling.

You will have to experiment with props to some extent to obtain the kind of performance you want. What will make things a lot easier for you, even with the prop you are using now, is to set up some mixes in your transmitter to offset yaw with throttle changes. Use the throttle as the master and the rudder as the slave. Input rudder in the correct direction in very small increments as the throttle is increased or reduced. It will take some time and experimentation but you will be nicely rewarded when you have it right. This is a very common practice in IMAC and other flight competition and is part of the normal flight trimming process.

Thanks for the help. The stall tests were done with rates on and whilst flying didn't feel like it had too much movement. The 'harrier' was obviously done with rates off.
Thought I might have to move the C of G back after reading all the threads many pages ago...........how could I do this??....... if not just adding weight to the rear. I thought of moving the rudder servos to the rear under the elevator servos. At present I have the two rudder servos ganged together in a tray in the main bay. With the elevator servos at the rear I'm not sure two more would fit, with the servo heads. Has anyone done this....do you have any pictures (im a visual learner...)

Many thanks for your help so far
Phil.

Two rudder servos is massive over kill if your using an 8611, 5955, or 8711. Tail mounting one or both works just fine and is easy to do. That's how I do most of the Wild Hare planes I have to offset nose weight. Only two so far have had a pull-pull, and then only for balance reasons. It's also more positive than a pull-pull. They fit in the holes provided for them with no problem. You may find that using only one works out a lot better for weight and balance as well.

I'm using 5955s all round. I hear what your saying about the overkill - I was working on the pretence that you can never have enough power or movement on the rudder.
do you ahppen to have any pictures of both servos at the rear.....not sure I could get even one to fit???? Will upload some pics later to show why. The servo heads will hi the servos
Cheers Phil.

You need to be a little creative with the linkage. The servo arms for the elevator or the rudded servo need to be opposite each other. For 3d the longest arm you want to use has linkage centers 1-1/8" from the output shaft. If you have 1-1/4" arms you need to grind off the excess length from the end of the arm. The linkage rod angle won't be a factor.

For precision or IMAC stuff you don't need an arm longer than 1". In truth, for most 3d stuff the 1" arms work well on the 35% Giles. I don't believe I have a picture of the Giles with 4 servos in the tail, but I haven't found a need for dual servos in anything other than the big Sukhoi so far, although I'm sure the 40% Extra needs them. Let weight and balance be your guide to the number of rudder servos. If it needs the weight, use two. If it doesn't, use one. The plane will knife edge loop all day with only one good rudder servo. That's a pretty good test of what a rudder needs for servo power.

Just for reference I have uploaded a photo. The servo head is pretty much right in the middle of the bay for the rudder servo. Will have a good look at it tomorrow night and try to work it out.
Many thanks for all your help and tips by the way.
Phil

You'll find that if you rotate the elevator servo so the output shaft is to the rear, and install the rudder servo with the output shaft to the front, the linkage will not be a problem if the rudder arm is fitted to te low side. Use a standard 4-40 ball link and clevis unit on the rudder tiller. Use either Tom's type or a Nelson/Rocket City. Doesn't help the Pro Link on the elevator but what can I say...

Hi,
I did all the changes mentioned and it worked very well. Brought the C of G back enough to make all the difference.
Unfortunately the covering came up on the leading edge of the wings on the last flight of the day last week. Wasn't too badly damaged but did break the fuselage in half at the back of the canopy. Seems to be easily repairable and has to be as it is great to fly either IMAC or 3D!!!!
Can anyone help with the colour of the Oracover/Ultracoat used for this Giles.....which yellow and purple

Tom will you ship the new Giles to the U.K.?

Cheers Phil.

Yes I will but it isn't cheap, probably something like $400 or 200 pounds. It doesn't sound so expensive when you say it in pounds.

TF

Right ok thanks for that will consider.......... Can you help with the colours of the old one??? Do you have any of the cowls knocking about in the purple, yellow scheme.
Cheers Tom
Phil

The old plane is cub yellow and pearl purple Ultracote with pink trim.

The new one changes the purple to midnight blue.

TF