A26 Invader 50" Foam Bomber Build

[LipoPilot]

Hi there

I wanted to build a twin engine warbird but couldnt make up my mind, after doing some searching I found the A26 Invader. I figured I could transfer the 3D views of the A26 to foam. Heres my attempt to build a 50'WS Pink foam A26.

History: The A-26, the last aircraft designated as an "attack bomber," was designed to replace the Douglas A-20 Havoc/Boston. It incorporated many improvements over the earlier Douglas designs. The first three XA-26 prototypes first flew in July 1942, and each was configured differently: Number One as a daylight bomber with a glass nose, Number Two as a gun-laden night-fighter, and Number Three as a ground-attack platform, with a 75-millimeter cannon in the nose. This final variant, eventually called the A-26B, was chosen for production.

START THE BUILD
Using the 3D views found on the web I scaled up the drawings to fit my build size I wanted. After the prints were made I cut all the foam parts. The fuse and the wing are 1/2 inch pink insulation foam from home depo and the engine cowls and side profiles of the fuse are 6mm depron. I also made the tail feathers from 6mm depron. I made two so I can glue and shape into a foil. I wing also foil shape the wing to. Did alittle temperary pin job to give the look. I still have to split black cowl pieces and instal the wing and tail feather holes.

[LipoPilot]

After getting all the parts made I wanted to see what the foam weighed before adding carbon rod, and glue ect.

6.570oz

[LipoPilot]

I split all the parts that needed to be, and did the elevator. I will do the alerons later. After cutting and tuning all the parts I pinned everything together to get the over all look.

Set the props on








What do you think?

[smokejohnson]

I think that it looks good so far .

[Larry3215]

Great start!

[LipoPilot]

Thanks, Im working on all the stuff that drives me crazy, like where to put this servo, sand this sand that, tape this. Also working on motor mounts and landing gear. Shes coming together nice.

[Crash Test Dummy]

Very nice indeed!! Keep up the good work. Do you have a power system picked out yet?

CTD

[CHELLIE]

Thats Looking very very nice get 2 tubes of 8mm carbon fiber tube in the main wing, to prevent flexing, and round off/Tapper all the leading edges to reduce drag, Just My 2 cents worth keep up the great work, Chellie

http://www.rcfoam.com/cart.php?targe...category_id=94

[LipoPilot]

Hi Guys...ladies pilots people thanks for the comments and ideas.

As far as power plants I had some HK 2409 T's with 25amp ESC laying around. So I plan to power the plane with them and 8.3 props. I dont think it will have problems but if it do...six screw and next size up engine will go in. No biggy.

What I'm using for power


Next came the fuse...I wanted to support it some, so I took a 1/2w but 1/8 wood flat stock to give some anti snapping. Laying it flat so it will shock on landing alittle, but my port to starboard flex will not be so much. Keep my tail stiffer I hope. Seems to be solid. I wanted to use a CF tube but this is what I had on hand. I forgot to mention this plane is being built by whats in the closet.


Looking at the real plane and the 3D views the plane has dehydral in both the wing and tail. Because I didnt have all the stuff I wanted to make the tail with this, I choose to leave it flat, if it doesnt work well this way I will change after testing. But the wing I wanted this. So I used CF tube with 1/8 rod inside for supports on wings. In the center I used a peice of brass tubing shape as a V for the center. This will hold my angle need while gluing to fuse, and give flight support.



Because the wing goes thru the fuse, I had to make it in two halves. These engine cowls are HUGE, no sliding them through the hole. So I installed the CF rod in one half of the wing with brass tube glued in place. This way I slide it thru the fuse, epoxy, then add other half. I wanted to make it so I could remove the wings, but didnt have the stuff to make a good joint, or atleast one I wanted to feel safe.


I used my soldering gun to make a channel to hold the CF and brass support. I will tape over after painting.


I got the angle I wanted, this should make her float good.


But Chellie thanks for the tips. I give most of what you see in my build...to the members here. Like I did your tips on wing edges, I foiled them if you can tell in photos. I'm using smokesjohnsons way of mounting the engines on sticks asked him that over on slowfly. Um gluing methods shown by many here.

It kinda went like this. I was cleaning out the closet, and I found stuff not used , some used. One hour later I came on wattflyer, asked about foam, then made another post about motor set up...and well the plane is getting closer to flight. Now that what the hobby is all about. And that was just twelve hours ago...Snappy plane service I say!!!! My parts your thoughts. Thanks to everyone for the tips, making your post I read but didnt ask questions. Thanks for the help for sure. I will be back if mom and kid stays away longer...I want a to do a hand toss tonite Flight maybe Sunday but that depends on time to finish.

[LipoPilot]

Oh ya a question. something i noticed I dont have. i dont have aleron or elevator horns. what is the best way to make them from say household items. I got some thin plywood. Plastic jugs.

And a question for larry the big foam guy, on my landing gear how big of a platform with plywood should I have to support the wheel pressure of landing. My landing gear is rigid no real spring to them. The bars and wheel will connect to the cowl sides under the wing behind motors, according the 3D's the wheels are just past halfway, retracting into cowl cover. My stick for motor will go under wing and cover the width of wing. I plane to attach the landing gear to this support to. I wonder the size of plate i should have above the gear in the wing for support.

[LipoPilot]

Ok had some time to finish up my motor mounts. Im using the smokejohnson way. The stick will be under the wing as shown, this puts the prop center in the center of cowl. Lower cowling half is slotted to fit around the stick.

[LipoPilot]

Gluing the wing now, next im going to want to install my motor sticks. Because Im using same rotation props, is there any angle to these, which way should they point, or do both engine run paralel with fuse. One mentioned without counter rotating props I would have some slight issues.



Im thinking of this paint set up after completetion, what ya think, anyone got photo of some cool ones...warbird paintjobs?

[Alpea42]

Cool plane , I've wanted to do a Mosquito this style wouldn't be that complicated.

[CHELLIE]

Originally Posted by LipoPilot

Oh ya a question. something i noticed I dont have. i dont have aleron or elevator horns. what is the best way to make them from say household items. I got some thin plywood. Plastic jugs.

And a question for larry the big foam guy, on my landing gear how big of a platform with plywood should I have to support the wheel pressure of landing. My landing gear is rigid no real spring to them. The bars and wheel will connect to the cowl sides under the wing behind motors, according the 3D's the wheels are just past halfway, retracting into cowl cover. My stick for motor will go under wing and cover the width of wing. I plane to attach the landing gear to this support to. I wonder the size of plate i should have above the gear in the wing for support.

Thin Plywood works great for horns as do Plastic Knifes, sand where they glue at, and take a t pin, heat it and poke out the hole with that, large zip ties work well, thick plastic containers work well to Hope that helps, Chellie

[smokejohnson]

I've used popsicle sticks with good results.

[CHELLIE]

BTW I love Pink Planes

[LipoPilot]

Im sure you do, pink is my fav too, but i have a attitude to carry here in the wheatfields, and pink aint going to get me any by stander lol.

Naw one of pals said I should paint it pink, because I named her Anna Nicole...my wife likes it, aww a big pink plane thats cute honey...gonna find me some pin up chick, but I dont think pink will work on this one. Cheerish the photos of it now, tomarrow it will look like a war torn A26

[LipoPilot]

Popstick wins the horn contest, one cut.

[Larry3215]

Originally Posted by LipoPilot

Oh ya a question. something i noticed I dont have. i dont have aleron or elevator horns. what is the best way to make them from say household items. I got some thin plywood. Plastic jugs.

And a question for larry the big foam guy, on my landing gear how big of a platform with plywood should I have to support the wheel pressure of landing. My landing gear is rigid no real spring to them. The bars and wheel will connect to the cowl sides under the wing behind motors, according the 3D's the wheels are just past halfway, retracting into cowl cover. My stick for motor will go under wing and cover the width of wing. I plane to attach the landing gear to this support to. I wonder the size of plate i should have above the gear in the wing for support.

If the landing gear legs attach directly to the motor sticks and the sticks run all the way across the width of the wing - that may be all you need.


Looking good so far!

[LipoPilot]

I managed to get the body all completed and painted silver. I will add all the electronics now and get her ready for flight.

[Don Sims]

Looking good Lipo!

[LipoPilot]

She will look better with her stars and numbers later. I determining if i want to add some sort of cowl nose to cover the fronts of engines, I think the look is funny with it open like this.

I also decided I will wait to add landing gear and test fly first since I dont know if it will. I will add landing gear after maiden.

[LipoPilot]

I added some more paint and installed the engines. Decided on black paint instead of making some plastic cowls for engines. I call this type of flight photos HOPEFUL lol. Maybe fly by wire?

[smokejohnson]

LOL nice job James...it looks great .

What is your AUW? It should be a rocket with 2 2409-12T's.

[LipoPilot]

Last time I weighed smoke it was 6.5 oz of foam, I figure my P51 was 14oz so this with double esc and motor i figure my AUW will be around 20 to 24oz. Thats just a guess. I plan to fly this with a 7.4 5200mah, one for long flights and two for some weight. I like my foam heavy for good stable flight in wind. I will give her a weigh and see the results as is, befoore servos and stuff.