56% KESL Flywing Build Thread

[ujjwaana]

Its almost two months since I crashed my Estratos with which I did my life's first maiden flight. I have already restored it on encouragement frm Ashta sir, nevertheless  I started with 56% KESL (18" WS) flywing , originally designed by RdJay on RcGroups:

http://www.rcgroups.com/forums/showthread.php?t=1040837

Material : 4mm Biofoam
WS:   18inch (56% of original)
Aerofoil : KFm4
Control surfaces: 2: Elevons
AUW (Target) : 140g (With all electronics and Lipo)

2x 3.7g HK servos
Futaba 4Ch 6004 Rx
Turnigh 10Amp ESC
Turnigy C1822 BL, 2100kv
4x4 Prop
Rhino 2S/3S 360mAh Lipo

Attaching the pic of the Biofoam cut and  slot for servo cutout

[anwar]

More build threads from you and Sunderam sir who seems to be back from his travels !  Brighter days ahead for RC India

[ujjwaana]

Anwar: All thanks to you for providing such a platform for us.

Now back to the Build. The plane is almost complete with the Rudder Fins and Decal remaining.

I really again enjoyed the build like the Estratos as it was not just cut form plan plane. I had to cut the pieces from guide dimension and much was left on me like how to 'Form' the KFM4 aerofoil, Servo linkage etc.

Before going forward, some explanation on the parts cut for the plane as it not very clear form the Illustration by the original builder RDJay.

1. The middle - Trailing edge piece - x1 .
This is which is sandwiched between upper and lower Leading Edge pieces forming the KFM4 aerofoill. This is the lowest most piece in the picture in the first post.

2. The Upper and lower pieces in the Leading edge, forming the FKM4 shape - x2
These are the pieces which are pasted together on the leading edge and pasted on the either side of the trailing edge pice.

3. Ailerons - x2

4. Pentagonal plate below the motor  mount - x1

5. Fins - x2

These pieces would be described in the the upcoming posts.


Below pics describe how to Cut and paste the Leading KFM4 part.

The simple strategy would have been to first paste the leading edge on either side of the trailing edge part and after is sets, join the the leading edge part. True to make-it-complicated  trait of yours truly,  It took the other path (just to add thrill)

1. Slice the thickness of the Edge of the leading at an angle to have a sharp leading edge on joining the two pieces.   - Pic 1 and 2
    I used a Hot wire cutter made of handle of Wall Painting roller and guitar wire (3rd no). First the end-point of the sliced were bounded between Aluminum foil and Metal ruler so that I get a uniform slice. (Pic-1).  The slicing was done at moderate temperature (no red-hot)

2. Join the two panels.  Here I realized my mistake. The slicing should have been done at more gentle angle. I spent more effort pater due to this mistake.

[ujjwaana]

Now its time to attach the Ailerons to the trailing edge part (Parts 1 and 3 described above).

I used simple transparent scotch tape for hinging (saving the 3M Blendrum hinge tape I got from Towers Hobbies for more exotic projects).

1. First slice an angled  cut (as we did above using hot wire) on the Aileron so that the trailing edge and the aileron don't restrict throw. I usually do it on the side facing bottom, mainly as I put the Control Horns on the other side. Whatever you prefer, be cautious on which side the slicing would happen for each left/right side. Mark it beforehand after dry fitting.


2. Now hinging. I used 3/4" transparent Scotch tape for hinging. I have kept the Towers Hobbies 3M Blendrum tape for later 
Tape the entire length of the side not sliced. Start from one side and unroll the tape till other end (i.e the width of the tape sticks aileron and the training edge).
On the sliced end, we would stick tape running perpendicular to the other side. We would stick in tree places - either end and middle. Start Taping from the free trailing end of the aileron, follow the sliced part till the tape touches tape on the other side, follow with the thickness of the depron on the trailing-mid part of the wing and tape 1" towards the leading edge.

3. Some Decal. I used some Red Packing tape to decorate the Ailerons. Its much neater than using brush as I don't have Airbrush. It also somewhat adds to strength .

[anwar]

Is it just me, or do the sizes of the wing versus control-surface look very different from the plan in the very first post ?  The wing surface looks much wider compared to the control surface in the plan (but not so in the model being built)

[ujjwaana]

Is it just me, or do the sizes of the wing versus control-surface look very different from the plan in the very first post ?  The wing surface looks much wider compared to the control surface in the plan (but not so in the model being built)

He He ... Bingo Anwar. The  Pic-8 in my last post has the aileron attached to the rear-Half (trailing part) of the Wing (the lowermost  panel in my first post pic) . The front  half of the wing are made my two almost similar panels (first two in my first post pic), folded to form KFM4 aerofoil. This part inserts over this rear part with the aileron.

Nice observation. The complete picture would get clear in my upcoming thread update.

[ujjwaana]

So Over a month and I did finish and Crash-Maidened the KESL. Have been lazy to update but R C coaxed me to put some oil in my machine and give his 32" KESL a company.

Till now We have the Trailing edge 'Center' piece hinged with Alevon and the Leading 'KFM4' sandwich pieces glued together.
Now below is how to attach the Leading/Trailing pieces together. i have used a small Vice to put them together. Dont forget to place a small Plywood plank/hard bound book between the Foam and the vice.

[ujjwaana]

Its time to attach the servos to the fuse.

Pic IMG_0204: One servo inserted in the slot, other one with empty slot

Pic IMG_0208:  Another angle

Pic IMG_0209: Both the servos inserted in the slot.

[ujjwaana]

Now linking the Servo to the Control Horn

Pic IMG_0210: Use the Push rods attached to the servo horns to determine where the Control horn be attached to Alevon.

Pic IMG_0211: Remember to have a slightly longer pushrod to begin with.

[ujjwaana]

Motor Mount

For motor mount, we have to little bit raise the platform to provide more surface area to attach the stick motor mount and also provide more strength.

Pic IMG_0212: The Pentagonal (Diamond shape) Biofoam cut to be placed over the center of trailing edge. 

Pic IMG_0214: Place where the plate would be glued

Pic IMG_0217: How to glue and hold the plate.

[ujjwaana]

Fixing the Motor

I have used the base of the plastic motor mount availble with RCDhamaka/HK

http://www.rcdhamaka.com/index.php?main_page=product_info&cPath=56&products_id=410

I removed the stick of the mount and glued a 3mm Balsa stick instead to save weight.

Pic IMG_0218 : Slot cut in the plate to recieve the mount. Note that the axis of the slot should be perpendicular to the Center line of the wing/Fuse.

Pic IMG_0221 : Mount glued to the plate.

Pic IMG_0225 : The Balsa stick glued and held in place with a Magnetizer. you can use your Coffee mug but ensure coffee is cold.

Pic IMG_0227 : Use a Zip tie to provide extra strength. Dont forget to reinforce the other side of the tie by placing 2mm ply or old credit card/CD ROM sheet between the tie and bio foam

[ujjwaana]

Almost Finished

Now Its makeup time! I used colored masking tape brought from Stationary shop to do some make up the KESL. Its much simpler than painting. And yes! thanks Hobby King for the free Decals. Sanjeev Sir, I hope you are listneing 

[ujjwaana]

Start the Engine....

Pic IMG_0282 : KESL cooling of on my couch.

Pic IMG_0285 : Colonial Cousins: KESL against Estratos

Pic IMG_0286 : Head On!

[R C]

Great............. your model is also ready to fly   

Hopefully this weekend we can fly.

[sundaram]

Amazing build and it is fabulous looking. Fantastic Job both of you RC and Ujjwaana.

Eagerly waiting for your flight video together.

[izmile]

Cool.. all the best for the maiden..

[iamahuman]

Beautiful plane there.All the best.