Ryan's Daughter - 52" Sport model Model Airplane (short) Kit

[slowjo]

Completing the Tail

Elevator:
Comprised of two parts that should be in line, on the same level, symmetrical and moving together. To achieve these goals you will have to glue the 2mm metal joiner correctly.
Assuming you have already drilled a hole in each elevator part, you will have to strip the coating and carve a shallow ditch in the balsa from the hole to the (internal) edge of the elevator part.
View attachment 173876

Prepare the joiner by roughing its surface using a file. Apply epoxy to the joiner and to the ditch and glue the joiner into place. Make sure the two parts of the elevator are in line and flat.
View attachment 173877

Insert the 4 hinges and apply a drop of thin CA on each one of the hinges. The joiner serves as a spacer.
View attachment 173878

Rudder:
Insert the hinges to the rudder and put it in place. Make sure that the notch is in position so that the rudder does not interfere with the elevator joiner. Note that I have mistakenly used only 2 hinges to connect the rudder to the vertical stabilizer. You should add a third one connecting the rudder to the fuselage below the horizontal stabilizer. Once hinges in place, apply a drop of CA on each one of them.
View attachment 173879

Controls:
Attach the control horns and the control rods. You might find that when the rudder and the elevator are in their extreme positions they interfere with each other. This should later be attended to by setting an end point to these controls using the transmitter.
View attachment 173880

You are practically done. The following picture shows the controls from below. Note that the rudder is off set due to lack of the third hinge.
This will be corrected.
View attachment 173881

3rd Rudder hinge
As I wrote, I had to add a third hinge to the rudder.

I removed the rudder's control horn.
I cut a deep slot in the bottom of both rudder and fuselage. Then I inserted a 3rd hinge as deep as I could.
View attachment 173888

Then, I cut it so it won't interfere with the tail wheel and secure it in place by the control horn screws.
View attachment 173889

Finally, I assembled a tail wheel which is not included in the original design.
View attachment 173890

enjoying the build

 

[Shaul]

Mount Motor

I use a motor which is way too powerful for this model (Propdrive 35-36 1400kv). I have quite a few motors at home. I chose this one primarily for it's weight.
I mounted it to the firewall with four 3mm bolts.

Note that the cables are going over the firewall.

plenty of clearance for the motor.

However, the cables prevents the canopy (hatch) from closing. I need to create headroom for the cables by removing material:

Now I place the cowling back in place.

Propeller (11X7) and spinner.

 

[TooJung2Die]

Your way of hollowing out the hatch works but usually there is an opening in the firewall where the wires come out of the motor. A u-shaped notch where the wires are going over the top of the firewall would've sufficed. Good looking airplane.

 

[Shaul]

Getting ready to fly

I now place the battery in place, make sure the canopy is secured in place. I attach the wings.
According to the plans, the CG should be located 6.2mm behind the leading edge. To get the CG right, I need to place the battery (1800mAh, 3S) to the extreme front.
I glue a slab of 5mm balsa as platform to which I will attach the battery. The slab is marked as "1".
I then drill 2 holes in the cockpit floor for the wing servo cables to pass through. Marked as "2" and "3".

Finally, I connect the wing servos to the receiver

And here we are, Ready to fly:

I tested the control surfaces for correct throw directions, the motor rotates to correct direction and for vibrations.
Well, no excess vibrations when throttle below 80%. Good enough for me for now. Ready to fly!

 

[Shaul]

Your way of hollowing out the hatch works but usually there is an opening in the firewall where the wires come out of the motor. A u-shaped notch where the wires are going over the top of the firewall would've sufficed. Good looking airplane.

The point is that the firewall is exactly the size of the motor mount, no leeway. Also, I don't wish to weaken this thin firewall.

 

[Shaul]

Test Flight

I took the model to the field yesterday morning. At 9:00AM it was already around 27C (above 80F) and the sun was glaring on my head. There was a nice breeze that helped with the take-off and landing.

Now here is my final set-up:
Battery: 1800mAh, 3S, 30C, 137g by HRB
Motor: Propdrive, 35-36, 1400kv Max current 45A
ESC: Turnigy, Plush-32 40A
Prop: 11X7

Some measurements:
Model total weight: 1030g
Aileron throw: Up=12mm ; Down 9mm
Elevator throw: Up=18mm ; Down 21mm
Rudder: Full throw.

C.G. supposed to be 6.2mm behind leading edge. I chose to make the model a little nose-heavy by shifting the battery slightly to the front.

Taxiing was quite straightforward though the tail wheel was a little wobbly. The runway is a wide and long strip of concrete.
Take-off was into the wind with as little throttle as possible. The tail wheel detached itself after a few meters, slightly dipping the nose towards the ground. I gently pulled the elevator and the model took off very smoothly.
Some more power and up to the sky.
Very minor trimming needed.
Overall take off was very easy. Perhaps should be done with a little up to the elevator.

The rest of the flight was easy.
Here are a few notes.

• The rudder is totally useless for turning. Perhaps useful for helping with smother turns.
• Tight turns result in substantial loss of altitude. knife-edge is out of the question.
• Rolling is very clumsy in this setup. I will try to increase aileron throw and see if rolling is an option.
• Motor becomes a little noisy on high throttle. Perhaps the spinner is unbalanced.

After five minutes of lazy flying I went into landing. The model almost glides at this weight so I needed very low throttle for the final. The landing itself was a little rough (perhaps I was nervous) and the model hopped a few times before coming to a halt.
Thanks to its robust undercarriage and wide wheelbase it suffered zero damage and is ready for a few improvements.
After five minutes of lazy flying the battery was at around 3.75V per cell so I think that 8 minutes would be quite possible.

There are a few things to be improved:

• Eliminate vibrations. Perhaps by replacing the spinner, or installing a smaller prop.
• I cracked the canopy every time I removed it. It is really brittle. I need to think of a way to reinforce it.
• Increase rolling by mechanically enhancing the aileron's throw.
• Cooling is a big problem. The model was not designed with cooling in mind so the motor, the ESC and the batteries were quite warm.

 

[TooJung2Die]

Congratulations on a successful maiden flight. Sounds like the issues identified during the flight are all minor.

 

[Shaul]

Thank you.
Yes, that's right. I'm mainly unhappy with her inability to roll. If you can't roll then inverted flight is also a problem.

 

[Tench745]

Sealing your aileron hinge gaps should help increase your roll rate. That said, this model says scale flyer to me, not sporty aerobat.

 

[Shaul]

Sealing your aileron hinge gaps should help increase your roll rate. That said, this model says scale flyer to me, not sporty aerobat.

Thanks for your input. Yes, you may be right. I will try to increase the throw and see what happens.

 

[Shaul]

Just a quick update.

Solved the vibration problem by:

• Using O-rings on the bolts that connect the motor-mount to the firewall.
• Using a smaller propeller - moved to 10X6
• Using a foam spinner from an old Multiplex Acromaster. (Not tested in flight yet)

Increasing the aileron throw did not change much. As @Tench745 said - this is a scale flyer. No rolls.

The new propeller also causes less heat so I will leave the cooling issue for now.

Lastly, I found the all-red look a little difficult to figure out. The model looks like a little red cross in the sky. I added some white to the wings. Here is how it looks now (Note the spinner):

 

[Shaul]

First crash.

Took off nice and gentle into the breeze (7:30 am) but refused to turn right. Tried hard so it turned but I felt I have minimum control over the ailerons. Made sure stabilizer (NX3) disengaged. OK. Still no real control over the model. Cut the motor and glide into a very distant field.

found it of a small bush, a little broken. Actually, disassembled.

Reason?
I suspect the new white pattern on the left wing came loose. Well, you can see it. I suspect that this the cause rather than the result of the crash. Well, now I see why it was hard to turn right.

 

[Shaul]

Some news.

The model was fixed and is back in the air. After a few flights, the battery and the ESC became too hot so I decided to add ventilation to the battery compartment.
After doing that, the problem seemed to have been solved and the Model looks (to me) even nicer.
I will soon post the intake building log.

 

[Shaul]

Ventilation - keeping the Battery and ESC cool

My task was to create air intake(s) that will stream a sufficient airflow on the battery while keeping the model aerodynamically "clean". I chose to open two apertures on each side of the battery compartment, and another, larger aperture at the rear of the model.

Location of intake apertures

The aperture size is 20X55mm.
Its size and location are dictated by several parameters: It mustn't damage the triangular beams that frame the compartment, it has to overlap the buttery height and it has to be aligned with the round aperture in part F2.
So I located it 30mm in front of F2 and 20mm below the upper edge of the compartment.


After cutting the apertures I also made the rear edge diagonal in order to improve air flow.

In the above picture:
The BLUE arrow points at the diagonal rear edge.
The BLACK arrow points at the bottom triangular beam that limits the aperture front edge.
The RED arrow points at the battery tray that limits the the aperture lower edge.

The Intake ducts

I cut 4 identical triangles out of a 3mm balsa wood board.
The triangles are right-angled and their legs are 85mm and 22mm.
The hypotenuse is of course about 88mm.
Cut a 24mmX88mm rectangle of the 3mm balsa wood board and make small dents (see picture below) so it can fit into the aperture. I used carpenter's glue to glue it all:

Once the glue is dry, make sure the ducts can be placed and mark their locations for gluing.


Prepare the duct for covering by sanding the surfaces and rounding the edges (Don't round the long legs of the triangles).
Cover the ducts.

Gluing the intake ducts to the fuselage
Remove some covering material from around the aperture so you can glue the ducts.

Put a few rubber bands around the fuselage.
put some carpenter's glue on the revealed surfaces and glue the ducts in place. Make sure the are horizonatlly and symmetrically placed.

Exhaust aperture
Don't forget to make an opening for the hot air. Put it at the rear of the model. The aperture should be somewhat larger than the sum of the input apertures.