Ultralajt`s World of Flying

Hi!

Long time no see!"

I starts to build an relatively large electric motorplane, for casual flying. It is an enlarged Czech FF rubber powered model MARABU.

(Note: photo above linked from this website: http://kopka.at/modell_f_slow.htm )

(Original plan)

I simply enla...

Hi!

I couldnt resist to start assembling fuselage! I mare a plywood motor mount, and plywood landing gear attachment plate and then glue to the fuselage sidewalls!

I am looking forward to continue...

Fuselage slowly got his final shape.

I made an upper sheeting with removable acces hatch piece for easier access to ESC and battery.

I did not go with oval upper sheting as it is on the original model. I just want to build fast&dirty   that s why I made flat sheetings.

I decided to make nose section of model a little strong...

Today I manage to complete landing gear assembly and a vertical tail.

Tail roughly attached to the fuselage with adhesive tape. Note large aerodynamic compensation of rudder. I will use small servos and want to make them life easier

Today I completed fuselage, glue vertical fin to it, and start building horizontal tail.

Some photos of the fuselage:

Close photo of the fuselage. Diagonals will strenghten fuselage against torsion.

Today I take horizontal tail from the workbench and roughly sand it.

Then I put it on the fuselage to see what is now the awerall weight of finished work.

Scale shown 760 grams, for parts as seen on the photos:

It was time to roundup the nose of the fuselage, by assembling the engine cover.I use thin plywood and balsa. Air intake is not yet at its finished shape, and I still need to roud more some corners.

I need to find some lightweight spinner as it will look a little more "aeroplanish"

It is time to jupm on Red Bull, for my model to get wings!

Last evening I manage to put wing planform drawing on the work table, and even starts to do some parts.

I made all four wing spars. They are of spruce caps and balsa shear web.

Today I will start to do actual assembly!

Right wing half is advancing on the assembly board.

It is going together pretty fast without any major obstacles.

As nose planking is very thin (1mm balsa only) I glue additional stiffener along top of nose ribs. (photo above...

Not much work done, but I manage to attach right wing to the fuselage using adhesive tape, to make some photos....

Today I take right wing out from the assembly board. Of course, first thing that interested me was the weight!

Wing as shown on photos below, weights 270grams. (Reminder: Wing dimension is 38 by 125 cm ... 15" by 49")

Now, there is no more much to add and work on the wing. I need to sand the leading edge, and all surfaces, separate flap and aileron from the wing, add reinforced rib at the root, add two small joiners at root wing.. and of course cover it.

But covering wi...

Today I started to assemble another wing half.

I install (glue) aluminum sleeves into a rear fuselage for the horizontal stabilizer joiners.

That way joiners could be replaced if something bad happens...

Today I use some sunlight to make photos outdor. It seems as model is in ARC stage, but looking closely, there is many tiny things to finish, before it will came to covering and RC equippment installation.

But I am happy that a progress is evident... so maiden flight is closer and closer!

Photo above: First time outdoors with all main componen...

Yesterday evening I install servos for the rudder and elevator. Then I use a steel cable to connect the rudder, and one carbon tube (4mm) for the elevator pushrod.

To prevent sideway bending of the tube, I stabilise it with a plastic guide.

As steel cables for the rudder crosses itself in the fuselage, I route them troug a short ...

Today my Marabu made first hoop trough an air!

I simply run, toss it, and moment later I catch him again.

It look sit will be real slowflyer.

See for yourself:

Othervise I can say, that model is RTF... Ready To Fly.

Of course there is still some minor details to finish, and some de...

Hi!

Model fulfill all my expectations and of course design goals!

Here is some videos:

Video with some music background:

Video of first flight ever:

I finaly complete decoration of the model!

I am flying whenever possible and I am looking forward to install FPV equippment in the cockpit!

Some photos made today:

CRASH!

Yes, my Marabu crashed couple days ago!

I install a video camera and video transmitter in the Marabu. As Video TX works on 0.9GHz and my RC equipment is working at 2.4GHz, I thought it will work O.K.

BUT it did not! Aproximately at 70-100 m distance, my Assan RC reciever went into Fail Safe mode. Motor stops, all cotrolls went into neutral and model starts to flyin a large circle. After a circle and half, it "landed" on the big tree.

Marabu got some da...