King Cobra

Hi everyone. My name is Matt and I am going to build a three foot wingspan by 38" fuse 'Nasty', using cheap white bead styrofoam I have had laying around for years.This may be a slow build because I have too many irons in the kettle,but, I do want to get this baby in the air asap. I would not suggest you try this at home . I will be reinforcing it with 'BOW & ARROW' carbon tubing. Please feel free to interject anytime you like. I would be happy to hear any suggestions you may have and I may use any of them. Thanks and enjoy. Matt

King Cobra

For starters, I am using this 3/4" white bead styro and it is never suggested to use such a product for any airplane. This will be a challenge for me to keep it from looking like a sudden snow cloud burst while flying . I have thought out my plan well and I believe it will handle pretty good flying punishment when finished. I will be protecting the leading edge and all other edges that may take abuse flying or landing. here are some pics of my rough styro and the cut-outs. Matt

King Cobra

Here it is the rough of it, cut and laid out. I will be sanding the leading edge, fuse(top and bottom), etc., starting with a 40 grit sticky paper in a piece of straight wood. That will be the next set of photos. Matt.

Rabbitcreekok

I will be watching the build.

smokejohnson

It's worth a shot. With some packing tape to help hold it all together it may work.

King Cobra

Thanks for the great replies. I took my foam to work after sanding the leading edge and fuse and checked the weights on each piece and then the the foam as a whole to check the mail scale for accuracy and it all added up correctly. I would like comments on what you think of these weights. One fella wants to stay under 20 oz. I am at 3.2 oz. now. I may be within fair limits if I am to use the Zagi 400. If I have too, I will use a bigger motor but my goal is, to use the 400. Matt

King Cobra

OK, here are the shots of the shots before and after the rough sanding using 40 grit sand paper. I didn't damage the foam because I was careful, but, in the future, I will stay with 80 grit. 40 grit is real abrasive and wanted to grab the foam so I sanded softer and faster. I will finish with a 120 grit by hand and those photos will be coming soon. I think building a plane is just as fun as flying it. Matt

King Cobra

I will also be searching for the printable version of WattFlyer to put on my wings. The topside will be spelled backwards so I will know when it is bottom side up Matt

Hostile

aero_k

Hey matt,

Looks good so far. I agree with Smokejohnson. I would cover it with some clear packing tape. It will add a little weight, but not that much. It will hold the foam together quite well and give it some impact resistance. I build a little foam tosser just for fun out of the white bead foam and covered it all with packing tape and it held together pretty well.

Good idea with the Wattflyer decal. To warn you, you're going to need more than some backwards lettering on it to tell top from bottom though. Once it gets more than 50ft away, you wont be able to tell the difference. Using two different colours usually works well, or dark and light. Loss of orientation is a leading cause of premature airplane death...

C140

It looks like it'll turn out nice. I've used that white foam for a while now, mainly because it's the only thing available where I live. It will take a beating and keep on flying. I cartwheeled that wing in the middle of the picture all the way down the runway, picked it up and flew it away again. I cut out my last few with a band saw, which is so much easier than a knife. For the most part, the leading edge is the only thing that needs tape, but since you're building a 3D plane it might require more.

King Cobra

Great to read all of your comments and tips. I took my plane foam pieces and electronics to work and weighed them individually and then in a stack as one pile to check the scale for accuracy and it added up fine. It looks to be on the heavy side so far but I may use different electronics and a Lipo battery instead of the Nicd's. Here is what I got. All weights are in OZ. My reciever is .8 / my servos each are .2 (HS-50) HS-55's are .3 oz. / my battery is 5.7 / my Zagi 400 minus prop is 2.6 / another motor w/ prop was 2.8 ..... All electronics added up to 9.4 and combined with my foam so far is 13.5. I think I can stay near 20 oz when finished. Matt

King Cobra

A new modification I made. I will be using these tougher foamy flaps I salvaged off another wing that belonged to a long lost plane. Looks like an old cub wing. Anyone recognise the factory wing numbers? This is nice foam and skinned too. Fits nicely. Before and after cuts. Matt

King Cobra

OK, I have been working on those cool wing flaps. I had to shave 1/4" off the top and sand the curve in for them to flip flop . I got up the nerve and used my table saw. I was sweating it but I didn't ment the styro I guess cause I slid it right through. After I did some shaping with my board sander by hand. I am pleased so far. Not much flex in that foam. I am going to have to strengthen the rear of the wing. I have ? oak? sticks and was thinking of using my dremel and make a slot to glue them in and then put the hinges into the stick. The sticks are stronger than balsa. I am afraid of added weight. Maybe bamboo skew stics. I am told they are strong. Here also are the carbon tubes I have. Maybe too heavy? I may drop by the hobby shop and look at their carbon goodies. Anyway, I have the flaps in shape and soon to smooth them with some kind of skin. Anyone ever seen mono cote put over foam or is the iron to hot for it. I am going to use Balsa lite over the grooves you see. Photos to follow. Matt

King Cobra

Here is my update. Thanks. Matt

King Cobra

Crash: Earlier I fogot to click on your photo until now. Those are awsome!!! And that Cessna looks like a kit from a box. Sweet! I bet a 400 would fly anyof those just fine. What is your latest project build? Nice! Here are some hinges I found in the shop. Matt

C140

Thanks for the compliment. You're right, the combat P-51 and the wing both fly off of a speed 400 brushed motor. My latest is a 3D bipe from plans. I'll throw a picture up in a while.

C140

Nice hinges by the way. How much do they weigh?