Estrellita EF1 kit build

[sihinch]

And here is my next project....

Ken Fluney very kindly cut and supplied me with an Estrellita EF1 kit. The EF1 planes are great fun to fly - either for sport or racing, and the Estrellita is my favourite looking one.  It has a gorgeous elliptical wing!

Ken can correct anything I get wrong but essentially all the EF1 legal planes use a 1250kV motor turning an 8x8 prop using a 60A ESC. They fly on 3S or 4S for sport and 4S for racing. They're all about 48" wingspan and end up weighing about 4.5lbs.

I promised I would do a build thread, but tonight I'm just unboxing.

[Polecat]

Simon The Estrelitta will keep you busy and out of trouble. Most of the work is building the wings, fuselage and tail are very easy.
Have fun and keep intouch.

Ken.

[sihinch]

So, I am not an accomplished builder.  I have built 4 balsa models since returning to the hobby in 2011, and before that built 2 models back in the 1980s, neither of which flew!  So this is quite a challenge for me......

And there's one thing I hate in RC models - torque rods for ailerons.  Guess what this plane has? Yep, torque rods! 

Ken kindly offered me some help on building the wing.  It seems simple, with 4 main components - 1) the sheeted foam core, 2) the trailing edge, 3) the wing tips and 4) the leading edge.  And of course the torque rods!

Given my previous experience with torque rods, and looking at the wings and components, I decided that I would mount the torque rod first, in the wing, and then add the trailing edge.  I learnt later from Ken that this is not the way he would do it (he would build the wing, shape it, and then cut the ailerons and add a channel for the torque rods.) 

I was very happy with how the rod went in to the wing, with a free movement and no binding.  Then I realised that to add the trailing edge, I would need to fit the aileron end of the torque rod in to the aileron.  Which was currently a piece of the trailing edge.  So, I cut the aileron now! 

I then added the trailing edge over the torque rod, and lined the aileron part of the trailing edge with 3/16 balsa strip.  I'm really happy with this part of the wing and it is definitely the best torque rod install I've ever done.  But it's not the way Ken would build it!  What it means for me is that I will have a harder time shaping the aileron, to the shape of the trailing edge.  Although I think this will be tricky, I still think I would rather do this rather than digging channels and adding torque rods after the wing is built.

So, I'm moving along, the functioning bits function.  But I've got a tricky task ahead to shape the aileron.  If I mess it up, I can just cut another one!  I think I will do a Frank and build the other wing exactly the same (making symmetrical mistakes!)

[GuyOReilly]

Looking great!
Love to see what and how people are building stuff.
I like your aileron installation and fabrication. 
Guy

[Polecat]

Simon  That set up will work, might be a little harder to shape the TE and ailerons. The method I used is what was used back in the 70's building the Formula 1 planes as they all had sheeted foam wings. You are doing just find, keep at it.

Ken

[sihinch]

A few steps Friday evening and a few more this morning......

Last night I sanded the aileron flush with the trailing edge and glued on the wing tip and leading edge. 

This morning I did lots of carving and started sanding them to shape.

Having a rest now before I decide how much to taper/sand the wing tip laterally.  Looking at photos I think it goes to a point?

[Polecat]

Simon  The tips should be a little rounder, check the drawings. Those tips where lazer cut for the Shark
The Shark has a different tail and the landing is mounted in the wings.
You are doing well on the wing, keep up the good work.

Ken

[cpaine]

Simon! this is great to see! the estrellita is one of the best ef1s for speed, take offs and staying "in the track" (aka the groove) when racing! I even have a paint scheme in mind for you!

I am a little late to the party, but would like to offer my opinion for whats it worth for any future building with torgue rods. I also noticed a potenial issue with how your torque rods are going to operate.

your build is looking great and keep up the good work! however, the idea of the torque rod is to operate along (in-line) with the hinge line.... the way you have constructed, the TR is trying to "lift" rather then rotate it. when the aileron gets installed, the hinges wont be flexing along the hing line but actually binding and trying to force them up..... i noticed this because you cut a little notch to allow the TR to move up and down. if its installed correctly on the outside of the cut, then the little notch isn't neccessary and the aileron moves very free. this is also putting more load on the servo.
im not tying to be nit picky, just want it to operate correctly... the one thing that will help if you dont change it, is these racers do not need a lot of aileron deflection.

look forward to seeing more progress!  and let me know if you want to see my "Simon paint scheme"

Cory

[sihinch]

Great catch @cpaine - thanks for spotting that!  So I plan to cut the trailing edge off behind the aileron, and cut 3/16 in to the wing so that the hinge line will line-up with the torque rod and then make a new aileron.  Do you see any issues with this?

And hell yeah, I'd love to see the "Simon paint scheme" but I reserve the right to completely ignore it if it's **** or too difficult to create! 

[cpaine]

I think i know what your thinking... and yes that could work. if you havn't beveled the aileron yet, you could add that 3/16 to the aileron (hinge side). the aileron will be a bit bigger but thats ok. also make sure there is still ebnough balsa stock on wing so the hinges have something to glue to... dont rely on the foam.

I don't want to cause you to many headaches, but another option is to cut off the balsa completly, then cut off another 1/8 off the foam core on the other side of the TR. then replace with 1/8th balsa in behind the TR. now the TR is inline with the hinge line. whatever balsa is missing from the aileron can be added later.

isn't building fun! lol whatever you end up doing the goal is to get it closer to the hinge line.
I love helping where i can.

if you dont use this scheme, i just might! I have an Estrellita kit collecting dust

Cheers
Cory

[Polecat]

Well I like the red and blue trim on the white but don't know about the other.

Ken

[cpaine]

Well I like the red and blue trim on the white but don't know about the other.

Ken

its Grey like the under belly of the Spitfire 

[Frank v B]

Simon,

Watch this Cory guy.  He is very competitive..... and may want to slow you down.   
I am sure his advice will be helpful as long as you fly behind him on the race course. 

Just kidding.  Always good to hear from you Cory...Mr. Eagle Eyes.


Frank

[sihinch]

Been a bit busy recently but managed to correct the torque rod on the 1st wing half and start building the 2nd wing with all the same mistakes from the outset. It's much easier making mistakes the second time round! 

[Polecat]

Here is one thing I for got to tell you, I do all my covering and then hinge/glue in. Then attach control surfaces.
Maybe you do this all really.
The wing panel looks good, keep at it.