1/4 scale KA3

loopingfred · 18-05-2006 03:02PM #1

Hi there,

So, after my 1/5.5 Grunau Baby, it's time for a new scale ship !
This time, the Ka3, 2.5mtrs wing span.
Let's glue some wood !

As usual now for me, I've started with the "front box" made with 3mm plywood (from the local DIY store...)

loopingfred · 18-05-2006 03:03PM

Then, it's time for hard wood strips to simulate the tubing construction of the real one.

I've used 10x3mm strps, but if I have to do it again, i'd rather use 2x 3x5mm strips. Much more easier to bend ! :rolleyes:

Nothing really difficult here. The hardest part of the building was for the rear part of the fuselage...Finally, no real difficulties, but you must be precise here !

loopingfred · 18-05-2006 03:04PM

Then, it's time to build the wings !

Really easy here ! Ribs are all the same (ok, ok, almost !), the wing is flat, rectangular... A real beginner wing here !

The first 4 ribs are in 3mm plywood. The wing spare come from the DIY shop and the key wing is in 8mm carbon rod.

loopingfred · 18-05-2006 03:04PM

Ok, so, we have a set of wings and a fuselage... time to put everything together for the first time :

Contemplation !

Fred --> happy !

loopingfred · 18-05-2006 03:05PM

So, it's time to start the "webbing" on the fuselage. First, I was thinking to cover the entire fuselage with balsa, and simulate the tubing with the 10x3mm strips... Finally, Why not reproduce the real structure ?! Less hassle ! And very light and strong ! (Ok, the weight is not an issue here in Ireland ! :rolleyes: )

loopingfred · 18-05-2006 03:05PM

Now, a bit of paint for the cockpit interior...

Ok, Grey like the Irish Sky !

Camouflage !

loopingfred · 18-05-2006 03:06PM

A bit of work on the wings now.
Put the TE made with 1.5mm liteply.

Note the wing root. Scale now (design error here...Ooopss)

loopingfred · 18-05-2006 03:06PM

Now, the ailerons :

Really easy.. nothing to be explained here... photos talk for themselves !

loopingfred · 18-05-2006 03:07PM

And finally :

So, missing on the picture : the wings root and the sheeting.

Now, it's time to start the V tail ! Yep, I keep the best part for the end !

Fred

loopingfred · 18-05-2006 03:15PM

Ooops, forgot to thanks Alan Perse for the 3 views !

Fred

Plug · 18-05-2006 04:33PM

She is coming on nicely. You make it sound so easy:rolleyes:

loopingfred · 18-05-2006 06:17PM

Thanks Plug,

But once again, nothing realy difficult here !

The real difficult part will be the V tail, not for the design, but because I want it removable (I have to be able to bring the model with me in contests) and with an Auto Lock of the moving parts...

But beside that, dead easy !

Fred

no leaf clover · 18-05-2006 09:40PM

omg!!! that things is deadly, im hooked, now!! dying to c the end result!!! nice work!!!

loopingfred · 19-05-2006 08:09AM

Thanks No leaf Clover !

Ok, let's make the wings tips.
One of the Ka3 Particularity is to have a hollow wing tip (mean that the wing sheeting is not going to the tips)
So, the last 2 ribs are made with 3mm balsa and the wing tip, by using 1.5mm liteply.
Here are the pictures before gluing :

So, this week end, the plan is to finnish the wings (sheeting) and to start the V Tail !

Fred

coolwings · 19-05-2006 08:15AM

Coming along nicely, Fred.
Keep the pics flowing please.

tallus · 19-05-2006 09:43AM

Looking Good Fred !

loopingfred · 19-05-2006 10:24AM

Thanks guys,

Hope everything is going smoothly this week End..

Fred

loopingfred · 22-05-2006 07:52AM

So, let's continue with the elevator :

The elevator is made like a wing. The profil is a NACA 00008. No spars but 2 wing joiners made with carbon tubes.

first, cut all the ribs (not a lot

) :

And glue them on a "false" TE, made with 4x4mm balsa strip :

Then, this is the critical phase of gluing the carbon tubes. Critical because you can input some wash-out during the process.... But slowly but surely, take your time and all will be fine...

Then, you can glue the TE to the ribs :

loopingfred · 22-05-2006 07:59AM

So, the sheeting is the only thing left to do, not before gluing some blocks inside the elevator for the hinges :

And finally, gluing of the "real" LE and sanding :

Et voila !

Then, the elevator (mobile one.. don't know the name for that in English..

). The building is like an Aileron, so, no big deal here.. :

You've got the idea... Only thing left here is to put the TE, made with 1.5mm liteply.

loopingfred · 22-05-2006 08:02AM

But before that, firt quick setup in the sitting room to confirm that i'm building a Ka3 :

Yep, I'm sure now, that's a Ka3 !

So, tonight : cutting of the plywood for the TE and start to build the mounting for the elevator on the fuselage.

Fred

coolwings · 22-05-2006 08:20AM

That is turning out really nicely Fred

loopingfred · 22-05-2006 08:37AM

Thanks Norman !;)

Hopefully, will be ready to cover at the end of the week...

Fred

loopingfred · 23-05-2006 07:40AM

So, let continue with the V tail.

So, I'm on target and made the liteply TE and parts for the V-Tail :

So, tonight, I go back to the fuselage and start the nose cone and the cockpit frame.

Fred

loopingfred · 26-05-2006 07:56AM

So, here we go again !
This time, on the fuselage and the cockpit section.

First it's time to glue the bottom canopy frame :

Then, cut a balsa block to fit the nose. The only "difficult" part of the job here is to respect the sides of the fuselage on the balsa block during the sanding.

Before :

After :

loopingfred · 26-05-2006 08:01AM

Then, as usual, put the wings on the fuselage... Can be proud of the result now !

And just for the pleasure, I've cut 2 tubes for the canopy frame to have an idea of the finished product.

Happy !
So tonight, the plan is to finish the canopy frame, and this week end, the wings.

See you on monday !

Fred

g5hn710m4xpdwy · 26-05-2006 09:17AM

noice work! i like the look alot for some reason

well i am off to get ready for exams, keep hte work coming :eek:

loopingfred · 26-05-2006 09:30AM

Thanks Flunked !

Slowly, but surely !

Must be ready for the Retroplane... So next week, must be finished !
Will not be easy !

Fred

BFassassin · 26-05-2006 09:52AM

looks good fred keep up the good work

loopingfred · 29-05-2006 07:53AM

Hi There,

This week end were the days to design the V tail mounting system. The trick here, is that I wanted to have the V tail removable in 2 pieces. The V tail is huge and if you really want to gain space, you need to have a 2 pieces tail.
So, finally, after 3 prototypes and a bit of brain cells, I've found a very simple solution to my problem.
4 pieces of wood, and 2 carbon tubes and that's it !

Then, plug both elevator/rudder :

Fit perfectly !

Happy !

loopingfred · 29-05-2006 07:56AM

Ok, so, I'm happy with the results, and now, it's time to celebrate by doing the wing sheeting and others details !

Happy ! Not a lot left to do now, and hopefully, I'll be able to start the covering this week.

Fred

Plug · 29-05-2006 01:15PM

Coming on lovely;)

1/4 scale KA3

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