1/4 scale Opel Rak

loopingfred

Hi there,
After the Ka3, new year, new projects !
We start with my new design, a 1/4 scale Opel Rak. You can find lots of picture and documents here : http://www.retroplane.net/forum/viewtopic.php?t=413


Scale : 1/4
Wingspan : 2.50 mtrs
99% wood, the remaining 1% are the aluminium tubes for the tail (12 and 10 mm diameter)

Central Wing section :

Ribs lovers, this model is for you ! 5 formers, and almost 100 ribs ! I can tell you that I'm happy to have a CNC machine ! So, here are all the bits and pieces for the wing :


The building of this central piece is not that easy, mostly because everything is built "in the air" ! So, you really need a good eye for everything to be square ! The spars (4 for each wing) are made using 8x8 pine strips.


Then, well, you just have to add all the other ribs !
After nearly 2 hours, you have something like this :

loopingfred

The tail booms are attached to the wing / ribs using 3 pieces of plywood that take the aluminium tube (a picture is easier to understand..)



Well, now, you can have a break (tea, coffee, alcohol or whatever you prefer !) and have a look at your latest baby !



So, the central wing part is almost finish. Next, the external wing sections (2)

Fred

g5hn710m4xpdwy

very noice, would love to see the finshed plane

loopingfred

Thanks Flunked !

Fred

loopingfred

So, here we go with the external wing panels :
So, at least 1 and a half panel is done ! I had a shortage of pine for the spars ! used 10 mtrs, and I need 2 mtrs more...

One panel :


Junction central wing / external panel :


Tonight, I'll try to finish the remaining wing panel, and the central wing section.

Fred

tallus

Looking good Fred

g5hn710m4xpdwy

yes it is looking good. you make it look so easy but with the help of the cnc :P

Is this going to have a motor or anything? or is it just a glider?

loopingfred

Thanks Tallus

@Flunked --> No, pure glider, but equiped with the rocket system, only for meetings and the scale touch (and the laugh if she start to go in flames ! )

Fred

Plug

i thought the rockets were illegal in Ireland?

loopingfred

Plug wrote:

i thought the rockets were illegal in Ireland?

Yes, they are, like the fireworks that all my neighbors are firing almost every night

No, seriously, the rockets will be only on meetings, and mainly in France anyway.

Fred

coolwings

I'd like to see it fly Fred.
Should be really something.
Will you get a video of the maiden flight?

loopingfred

Hey Norman !
Well, I expect the thing to fly pretty much like a truck...:p But as usual, a video of the maiden flight / crash (we never know ) will be available.
Such as the test with the rockets.. We might have a laugh here !

Fred

loopingfred

Ooopss, forgot today's update on the building...

Not a lot of work done yesterday, but things are still moving !




Plan for this week end : TE and LE for the wings and I start building the fuselage or the tail section, we'll see.

Fred

g5hn710m4xpdwy

thats long... ...very long...:D

Plug

i thought my glider was long!:eek:

g5hn710m4xpdwy

you have a glider

Plug

yeah! Posted up crap flights and a pic or 2;)

g5hn710m4xpdwy

oh...:D

Plug

Lost intreast in it tho, couldn't fly the thing properly, nearly toke the head off my brother at one stage:D

g5hn710m4xpdwy

That's no reason to stop! Tis a reason to keep doing now that you know what it can do:D

loopingfred

Hi there,
I agree with Flunked.. Not a reason to stop !

If you live around Dublin, why not joining us on a slope with your glider and radio to have a look and why not, take your first flying lesson ! :rolleyes:

Contact on the link below or here : http://www.islandsloperebels.com

I go back to the garage now !

Fred

Plug

2 channel radio and a wing as balanced as the leaning tower of peisa.

g5hn710m4xpdwy

I thought you were in Cork. I am in Dublin [even tho I dont think you were talking to me] And I would love to get into gliding if theres any very cheap started kits or used models. I need evrything but the radio controls;)

Plug

Want to buy mine?:D I'll give her a bit of a service and balance the bitch;)

g5hn710m4xpdwy

dpeneds what your selling for. looks like your hitting the mighty 2000 post tonight, make sure it is done in this part of the forum!:D

Plug

Won't be too much, whats the budget?

Don't worry i'll save it for here:D

loopingfred

Hi Flunked, Anytime !
Check the forum in the slope rebel site or the gliderireland one or contact me if you want to have a look at the slope with us a week end !
For a beginner glider, let me know if you need one (if Plug want to come back to this hobby ! and he will.. Come on Plug, let's try it again ! )

And if you have any questions...

Fred

loopingfred

Hi there,
After a Saturday at the slope, a bit of work has been done sunday on the Opel, starting with the fuselage. The pieces :



Not a lot ! So, that goes really quickly to assemble :


After that, not a lot of work need to be done on it. Plywood sheeting, and space for the pilot, batteries and receiver.. Yep, no servos on the fuselage, they are all in the wings and tail !
First look at the fuselage with the wings :

Well, looks like the picture... Always a good sign !
Back to the wings for a while, and it's time to glue the LE (10mm balsa) and the TE (1.5mm plywood) :


Then, we do the same on the 2 external wing panels, and we can do a final setup and have a look back on the beast :



Well.. Not bad at all ! And the more I look at it, the more I think that can have a decent flight !

This week, it's time to work on the tail (elevator and rudders) section ! More ribs !

Fred

Plug

Coming on nicely fred;)

g5hn710m4xpdwy

Nice
Looking like a flyer rather than a sophisticated ladder now:D
I'll PM you about the me getting into gliding

loopingfred

True actually !

You can contact me at anytime ! And if you want to join us in a week end to have a proper look, no problemo !

Fred

coolwings

That is shaping up nicely Fred. Very unique looks. Sorta Cessna Skymaster meets Ka - with a rocket - just for added fun!

loopingfred

Hello there,
Back to the building, and this time with the elevator section.
Not a lot of pieces for the fixed part :

And we glue everything together ! The central rib id made in 3mm plywood and will received a mini servo for the elevator :


Then, the stab TE is closed with 1.5mm balsa, and the LE made as usual with 10mm balsa. A balsa block is cut for the stab ends, and will later receive the rudders. Et voila :


Tonight, rudder or elevator.. We'll see ! :rolleyes:

Fred

loopingfred

Hi there,
Here we go again, this time with the fixed rudders. First, cut the parts. The plywood is used for the aluminium tubes brackets (not sure of that word..) :



Then, nothing really difficult. Just a puzzle to assemble :



Just to have a look at the beast, and have an idea of what the finalize project is going to look like, I've setup the elevator/rudder on the booms. we can see a close up of the rudder / aluminium tube junction. Easy and simple ! :



And a general view :



Well, so far, I'm happy, and the machine is looking really good. I even start to like it !
The glider seems to be light so far, and that's good as not a lot is left to be done (sheeting, and all the moving things (rudder, elevator , ailerons..).
Almost there !

Fred

loopingfred

Hi there,

I finally received my plywood for the Opel !
0.8mm plywood for the fuselage, and 0.4mm for the wings.

I've started with the fuselage flanc, to finish (for the time being) with the bottom fuselage. That still give me access via the top section to the fuselage interior to install the pilot seat and so on before closing the fuselage definitively. Easy to do, but no mistakes allowed with the plywood, but by going slowly that do a perfect job !





For the struts, I've cut the space for them after I've glued the flancs. Easier that way, once again if you are carefull (using a small router) :



And that's it for now ! This week end, I'll finish the fuselage and start to cover / do the sheeting of the wings.

Fred

loopingfred

Hi there,
Almost there ! I think this week, will be my last one on the Opel.

Here are some pictures :


Plywood, it's beautiful ! I think I've just fall in love with this material ! So much easier to work than the balsa !






I just have to finish the sheeting under the wings on the fuselage, but I leave it like that for now as I'm doing the servos wirering.. Just in case.. But nothing is glued yet.

loopingfred

More...



1 servo / rudder. you can also see the rubber, used in kites that has been modified to connect the 2 tail booms. Almost like the real one ! And simple !



This week, I just have to keep concentrated to all the moving parts (rudder, elevator and ailerons) and finish to install all the electrics cables and so on. After that, that's the finishing.
ARTF !

loopingfred

Well, after a lonnngg break on the Opel (almost 2 weeks without gluing wood...:o ) back to work ! ARTF !




Just to give you an idea, here is the model, ready for transport... You need a bit of space, but no other solution at that size / scale.



So, this week, last week on the machine ! Just to do the electronics, covering and finishing... May be not fully ready to fly next week end, but that will be really close !

The Doktor

Lookin really nice. Tis a credit to ya.
Always wanted a glider meself... guess I`ll put it on the list...:D

g5hn710m4xpdwy

looks really nice/big:rolleyes:
Cant wait to see it covered

loopingfred

Thanks guys ! Much appreciated !

Thanks to Anthony from http://www.rubberprintdesign.com, here is the PDF file for the Opel Rak Letters.
The scale is 1/4, but for those interrested, he can cut them at any size. And he is a modeler, so, he will understand what you are talking about and what is you really need ! :rolleyes:
The file can be downloaded here : http://www.gliderireland.net/files/...tersopelrak.pdf (800 Ko)

Fred

loopingfred

Hi There,
The covering is on the way and almost finished !


Don't know how to cover a wing like this ?
Here is a tutorial for you !
http://www.gliderireland.net/covering.htm

Fred

loopingfred

Hello there,
Well, the Opel project is almost finished ! Ready to fly !
Now, waiting for the good opportunity (next week end should be the good one), I can concentrate on all the small details... Cockpit, rocket pods, wires and so on.
And thanks again to Anthony for the lettering !

loopingfred

And to finish :



Next, in flight pictures !

loopingfred

The Opel has flown !

Well, back from Retroplane 2007 ! The Opel did is maiden voyage the saturday of the meeting.
To tell the truth, the real first flight was a bit.. disapointing !
Launch, went straight, but the glider did not want to go up !
Flew like this for 5 minutes, and then land... We've just look at each other with Joe, thinking that this thing will never fly (well... 100% scale, the original did not much better ! )

Analyse of the flight, then, that was obvious that the CG was a bit too much forwrd...
Removed around 40 grs of lead (the only piece of lead I was able to remove...) and off we go again...

And we saw the light, right after the second launch !
What a flight !
the 40 grs made a huge difference, even if the machine is still nose heavy.
Just the trim at the ailerons to be touched, everything else is fine. Rudders are really powerfull and the shape of the glider in the sky is really uncommon ! Really looks like a WWI bomber with the two tail booms !
I flew lots of low passes, just for the pleasure (and the photographs )
So, here are a few pictures... A video will follow soon (and more pictures...)
Enjoy !

The launch... Where you try to think if you forgot something !


In Flight

loopingfred

Guys,
The Retroplane 2007 photo album is now online !
More than 300 photos are available - Broadband is required !

The link :
http://www.retroplane.net/album/index.php?cat=11

Enjoy !

loopingfred

Hi There,

In flight video of the Opel is now available !
Taken during the Cork / Kerry Fly-in the saturday.

Enjoy !

http://www.gliderireland.net/images/videos/OpelRak.wmv

13 Mo - 2.30 mins.

Fred

coolwings

Hi Fred

The Rak certainly flies nicely. You must be pleased with it.

Will we be seeing a flight with flames, smoke trails, and rockets attached soon?

loopingfred

Hi Norman,

Well, Everything is ready, I just have to sort out the way to light the fuse remotely (I don't want to die ! )
But for now, I'm a bit busy with another little project :



But getting there !

coolwings

loopingfred wrote: »

.... another little project :

... "little" project ....

loopingfred

:p

1/3 scale Ka3, enlarged from my 1/4 scale plan...
Well, that take some space !

More info here : http://www.gliderireland.net/forum/viewtopic.php?t=277

Fred