soggi.ca

The "Pork Chop" is finished!

AUW 150g. This comes out to 2.8 oz/sq.ft. wing loading. Perhaps it is too light, but we'll find out.

I had an old 27Mhz AM radio and receiver in V tail mode from a crashed foamie that in large part taught me how to fly. It is not super accurate but hopefully will do the job. Modern electronics could be lighter.

The batteries are 2S 180mah lipos (10g pack), but then I needed 15g of nose weight, so eventually will change these if flying is successful.

No idea how large the winglets are supposed to be . Just an eyeball, probably too large. Yes, those are from the meat section.

Backyard fling tests determine that significant reflex is needed in the elevons. The CG is 20% for first flight.

I may try it out tomorrow!

Here is the covered wing, weight 71g.

I tried two different translucent coverings. The green is Hangar 9 Ultracote, and not sure what the blue is, but it's an ultralight covering about 1/2 the weight of the green one. I prefer the blue ultralight, because it shrinks at lower temp and produces fewer bubbles and has better adherence. Both coverings strengthen the wing significantly, and will warp it up or down, then you have to go back and even it out.

The elevons are a bugger, because they were quite straight, then the covering warped them like a samurai sword and it seems nothing will get them straight again. Probably because of the taper. They are however MUCH stronger with covering.

Hinges are just roughened flexible plastic rectangles, don't know what you call them. Just made a 1x0.5" cut in three places in the elevon and wing, guided by a metal ruler in thickness, and it turned out better than I thought.

The really neat thing about foam is that iron temperatures will pull out dents so well that you can't even tell they were there! Hopefully this will be useful for Westover rash.

Getting started on a flying wing, airfoil is HS522 or thereabout. I don't yet understand the coordinates so it's just roughly based on a blowup of the diagram.
http://www.aerodesign.de/english/profil ... .htm#hs522
http://www.aerodesign.de/profile/hs522.gif

I also considered this one:
http://www.aerodesign.de/profile/hs3080b.gif

WS 36" root chord 10" tip chord 5" sweep angle 30 degrees. Airfoil thickness at root is 15/16" which means 1" foam sheet is adequate.
This site will be very helpful:
http://fwcg.3dzone.dk/?wing_span=35.9&r ... ac_lines=0

I used radial foam cutting technique, with about 24" heated section of 0.020 stainless (thanks Ray), radius about 38" from root leading edge. 12V car battery at about 4.5A gives good heat. Not sure with how much force I'm pulling it, it's all done by feel. But this was too much tension for (thinner) guitar wire, which broke twice in testing, which ruins the wing quickly! What you see in the picture is attempts 3 and 4, not perfect but looks flyable. You need a steady hand, any catches on the guide make ridges in the foam. It took about 30 mins to set up and cut two wings.

Now I'm testing some covering material, white glue, iron-on etc. Fibreglass is a no go with eating foam, and stinks too much anyway! Will keep you updated.

Anyone interested in doing the same, please come by and we'll cut some wings! Bring some 1" stuff of your colour choice, and use my HS522 guide or make your own, then we can compare builds and flight success!

Any hints about elevon construction, stiffening, hinges, or anything else would be appreciated.

Ted,

Thread with Slope Soarer plans:
http://www.rcgroups.com/forums/showthread.php?t=301997

Andy

http://www.rcgroups.com/forums/showthre ... 264&page=3

Ted,

See post #32 in the above RC groups link for a video of the Halfbad.

Andy

Ted,

I have a 0.6m Halfbad wing and still have the female foam halves that the wing was cut from. You are welcome to them if you can use them in any way. I could also draw it up on Autocad and scale up to 1m but don't know how accurate that would be. I don't know what the airfoil is but it could be easily traced out.
Were you thinking of scratch building though because there are lots of relatively cheap foam wings on the market. I think the trick is to find one that would be good for Westover conditions. I have not had much luck with this model but I think that is just my inexperience with setting up and flying foam wings.

What I can say about the Halfbad though, it is virtually indestructable.

Andy

I have decided to build a rough and ready slope flyer this winter, and something like a 1m foam flying wing seems to be just the ticket.

If anyone has advice on plans please help!