Here is an Extra Spad build...
Since the timeline for the sweeps gives some 'extra' time, I thought of doing an Extra build. (Although I started the wing sometime back)
The spad plan on STTB gave me a starting point. I've tinkered with dimensions a little and used 5mm coro for the fuse and the stabs. The wings are made with 2 mm coro, The wingspan for the SPAD is 54 inch but I;m doing a 48 inch version.
The Extra seems to be a fairly acrobatic craft (though I still don't know how to xecute a loop in the perfect vertical plane )...
I wanted to use a semi symmetric airfoil, so opted for a spar+rib design. Could've used 5mm coro on one side and 2 mm on another to do a semi symmetrical wing but wanted to checkout cutting ribs in coro (it's a pain, I know now).

Here are some pictures...

More photos

Sure looking good! Why so kanjoos on the ribs, put a few more

Thank you Rai sir,

The wing is now closed , so can't add more ribs without taking it apart...perhaps in the next build; cutting the ribs was the most difficult part, and post the cutting, I tried everything from sanding to planing to chiseling to shape the coro using a paper cutter, nothing really works well

Here are some pics of the closed wing and the empennage

And here is the first scar!

I was trying to glide test the wing by attaching a MDF strip (to behave like a fuselage), balancing the CG at the spar and launching it. While I could see some glide, the side of the wing struck an obstacle

Girish sir beautiful and Strong build..

Many thanks swizera for the compliments.

Dear Grish
Very good build

very good and colorfull build.... , pl post the side view of wing ( for airfoil look).

Thank you kamaraj ji, the real goodness will only be when and if it flies well or it will be in the 'hanger' (hung from a wall)...

Thanks Mjet, sure I'll be posting the side view soon illustrating the aerofoil section...

@Girish.. These models with symmetrical aerofoils will never glide . its the airspeed and the elevator throw that will guide it. . u r soon gonna have some real fun . I have been scratch building from quite long and that justifies the diff in aeromodeller building from scratch and aerobuilder assembling arf
. hehe.long live aero modellers.

Absolutely Sujith, symmetrical aerofoils have almost no authority of their own in providing lift, it's the elevator throw, for this build I'm considering a semi symmetric one which probably caused whatever little glide...

The aileron template was chosen based on some resources on the internet and a causal look on the spad extra wing in the original build. I am using a 10 inch chord with 18% thickness (high drag) although the extra should be a fast flyer for obvious reason, but I need some slowness to be able to control this thing (for sure I am expecting loads of fun on the field..hehe)... I am sure with so many resources and people on RCI, I will end up being in the aeromodeller clan

Once i finish off the frame, I will need some help from builders like yourself in considering a power system. I am at the moment considering a 2822 1400Kv with a 8x4.5 prop, burning about 30A on a 2200 LiPo, but I also have the option of mounting a .46 nitro with a larger prop (and there will be CG changes ). Your recommendations will be of help

Honestly Girish, you can't write 2822 & 46 in the same line.

Even a 3548 has the power of a 25~30. What soes STTB say? 46? Then stick with that, or dramatically reduce the weight

Thank you Sanjay sir. Get that totally, they're miles apart. I will stick to the specs till I gain more experience to experiment. although I have reduced the weight and the size. Many thanks for the inputs.

Quote from: girishsarwal on March 05, 2013, 03:35:46 PM
Absolutely Sujith, symmetrical aerofoils have almost no authority of their own in providing lift, it's the elevator throw, for this build I'm considering a semi symmetric one which probably caused whatever little glide...

The aileron template was chosen based on some resources on the internet and a causal look on the spad extra wing in the original build. I am using a 10 inch chord with 18% thickness (high drag) although the extra should be a fast flyer for obvious reason, but I need some slowness to be able to control this thing (for sure I am expecting loads of fun on the field..hehe)... I am sure with so many resources and people on RCI, I will end up being in the aeromodeller clan

Once i finish off the frame, I will need some help from builders like yourself in considering a power system. I am at the moment considering a 2822 1400Kv with a 8x4.5 prop, burning about 30A on a 2200 LiPo, but I also have the option of mounting a .46 nitro with a larger prop (and there will be CG changes ). Your recommendations will be of help

18% thickness is too much.. would be good if its 10-12%. these are fast flying models.. seconly power system seems to me perfect for a model weighing ~ 1kg..

but as suggested stick to SPAD's build.. ( u can do ur own R& D though).. but 2822 is nowhere near a 46 nitro motor..

i recently converted an old trusted plane ( baught it when i was a beginner) .. it had a 2822 motor on it.. now glow powered it with a ASP 12  size engine and 7 XX 5 prop.. and still its over powered.. somehow.. notro motors generate more power in the same line

Thank you Sujith. I will stick to the 46 for this build.

For your eyes Mjet

Well, although you said mjet,I have had a peek. Looks vrry very good

Sent from my GT-S7562 using Tapatalk 2

thanks girish, clean and good finish 
it looks like semi symmetrical, but extra may need symmetrical profile.

Thank you both; this is totally an experiment . I have also tried to make a rectangular fuselage for this one 5.5 inch across by 4 inch height strengthened with 2mm ply firewall (.46 mounted) and coro fuse formers . Pics coming soon

waiting for Fuse Pics. 2 mm ply is sufficient for .46 engine? i have used 12 mm ply in my SPAD for .46 engine 

Yups, 2mm itself was not going to hold the engine. so this is what I've done

1. There is another 2 mm doubler at the back where the engine mount bolts in, washers used of course. The doubler grain runs perpendicular. Teak ply used.
2. Wedges on both side edges where firewall meets the coro to increase surface area for glue. Held tight using gclamps for gluing.
3. Tongue and groove in the coro at the bottom. The ply tongues into the groove for gluing. Everything glued using epoxy (Fevitite).

The joint feels pretty strong. I haven't started the engine yet; will be doing it this week and update. Pics upload will be sooner

Pictures of the fuse and the engine mount

I have a feeling the wing span is small...

This build was lost somewhere, gathering dust...

After some positive motivation from sanjay sir, and a random shuffling of items in my hangar, this build had been revived...Fixed up parts of the turtle deck today for vinyl covering...

The firewall has been replaced with something more durable