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;)

loopingfred

Well..

A bit late on schedule, but finally, the Ka3 is ready to cover !
This week end was just a bit of work on the scale details on the cockpit :



Almost finish by now.
Then, it was time for a last look at the wooden structure before the covering start :







Hopefuuly, finished to cover during the week, and maiden is plan this week end, weather permitting !

Fred

loopingfred

Hi there,

Quick update on the KA3 with the covering :





And the painting of the fuselage, just to have an idea before starting the wings and elevator :



Nearly there !

Fred

loopingfred

Hi There,

Quick update on the Ka3
Here is the Ka3 as it was yesterday evening ! :



and




All servos fitted and so on... Ready to fly !
Just the paint need to be finished (not a lot to do..).

Hope to do a launch on sunday, or monday evening at last.

I will complete the test flight in France before Retroplane.

Fred

coolwings

It's looking really nice Fred.
I like the colour scheme.
Is the R/C inside yet?

loopingfred

Thanks a mill Norman.
Like the red too ! Really vintage colors on a glider.

The glider is ready to fly. Just some paint touches to be done, but the priority is the first flight for the week end.
But the paint should be finish tonight. Just the masking.. lots of time !
6 hrs of masking for 15 mins of painting !

So, first launch this week end, weather permitting of course !

Fred

syl77

Me likes the colour scheme also..done well.
Do the wings come apart....

loopingfred

syl77 wrote:

Me likes the colour scheme also..done well.
Do the wings come apart....

Yes, wings and V-Tail.
Easier for transport !

Fred

Plug

Exact same colour sceme as my one. Great minds think alike;)

loopingfred

loopingfred

Job Done !

The maiden flight has been made yesterday !
Short flight (5mins), but what a flight !

No trims to touch, very effective ailerons (despite the size). I'm ready for Retroplane in July now !
Need to do another proper test flight (may be this evening, weather permitting) but I'm now confident that she will fly, and well !

Fred - Happy !

coolwings

Congrats Fred. The successful first flight is always the most memorable.

vectra

Congrats again ..
Its great to see projects working out like that...
Makes it all worthwhile in the end

Plug

vectra wrote:

Congrats again ..
Its great to see projects working out like that...
Makes it all worthwhile in the end

Brings a tear to my eye:D
.....lovely model though;)

loopingfred

Thanks Guys !

The Ka3 looks fantastic in the air ! Looks waayyyyy bigger and remind me my Lo100 !
And the V tail !
God that was good !

Next flight, in france now !

fred

loopingfred

Hi There,

Just back from France and the Retroplane meeting.

And here is a best off of the in-flight pictures during Retroplane of the Ka3.














Fred

loopingfred

And guess who won the Retroplane trophy ??






Fred

g5hn710m4xpdwy

nice ;-) me likes it

coolwings

Hey - how about that!
Well done Fred.
:-)

loopingfred

Thanks Norman !

Fred

vectra

Great news Fred.
Congrats