1/4 scale KA3

loopingfred

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

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

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

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





Contemplation !

Fred --> happy !

loopingfred

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

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

Ok, Grey like the Irish Sky ! Camouflage !

loopingfred

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

Now, the ailerons :

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

loopingfred

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

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

Fred

Plug

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

loopingfred

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

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

loopingfred

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

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

tallus

Looking Good Fred !

loopingfred

Thanks guys,

Hope everything is going smoothly this week End..

Fred

loopingfred

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

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

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

That is turning out really nicely Fred

loopingfred

Thanks Norman !;)

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

Fred

loopingfred

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

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

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

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

Thanks Flunked !

Slowly, but surely !

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

Fred

BFassassin

looks good fred keep up the good work

loopingfred

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

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

Coming on lovely;)