40% Extra 260: Own-design build thread

[dmichael]

I fashioned my own rudder horn out of 1/8" and 1/4" aircraft ply. I had a little bit of apprehension that it would hold but it has proven to be solid and shows no signs of wear after 250+ flights.

First picture is of the rudder horn and second is the hole for the horn. I epoxied it in all around and later painted it after covering.

[dmichael]

On to the cowl.

I was able to get a cowl from the Radiocraft 40% Extra - this is the same cowl found on the Radiowave 40% Extra today.

I tacked it in place with CA after positioning and clamping the bottom half of the cowl ring in place. I did the same with the top piece and then tied the top and bottom cowl rings together with two small pieces of aircraft ply. After that I used fiberclass cloth strips and epoxy to finish gluing the cowl ring in place after roughing up the inside of the cowl with sandpaper and then cleaning with alchohol to remove the dust.

The cowl mounts with two screws on top that are accessible from the hatch area and two more on bottom from the front.

[sweetpea]

GS racing sells those blue washers. Car guys use em.

[dmichael]

Thanks, sweetpea- got a website for GS racing?

[3DFreak576]

you can also try Hirobo. I know some of us shankboners use them on our helis

[dmichael]

I'll take a moment to mention the gear design. I came up with a basic look and shape of the landing gear and called TNT(http://www.tntlandinggear.com/) and ordered it. They did a great job of producing and sending it to me in no time.

You'll notice from the picture that the gear hangs out over teh side of the fuse a bit. I did this on purpose. I planned on adding cuffs to the gear and used this overhang as a way to make it look like the gear was coming out of the corner or even a bit up the side of the fuse without having to build a channel in the bottom of the fuse. This worked out great. I was able to get the look I wanted without going to the additional complexity of building the channel and I was able to keep the cannister tunnel intact - leaving the most amount of space available for the cannisters.

[dmichael]

OK. So at this point, the fuse is framed, the tail feathers are constructed, the cowl is mounted, the gear and tailwheel are mounted and the hatch is framed. Here is a picture of the fuse- note that the tail feathers are not hinged in this pic but it should give you an idea of how it will look.

[Ian]

wow!

[dmichael]

More.

[dmichael]

Here's me in my usual position stressing before the unknowns.

[TheTank]

Classic Dave sitting position during a contest... although with a new chair now... Thats the position you were in this year at Del-Gap when I was talking to you and that Mid-air happened... I almost jumped out of my skin when you reacted! Awsome thread Dave!

[dmichael]

Wings.

As mentioned early on in the thread, my original intent was to use foam ribbed wings- I didn't end up doing that for reasons that I'll detail later. Having said that, since I did attempt to make a foam ribbed wing and since so few modelers know about how to build a foam ribbed wing I'll lay out some detail on this topic.

On the Staudacher that I built years before, I built a fully sheeted foam ribbed wing. It was light and strong. That plane is now about 10 years old and it's still flying. The guy who owns it beats the crap out of it- club members are just waiting for the plane to fail when they see him fly it. So- my opinion is that foam ribbed wings work great- but are a lot of work.

I originally learned about foam ribbed wings when I was building my first giant scale plane back in 1996- a 1/3 laser from Wayne Ulery plans. Some of you may have heard of Wayne Ulery as the man who worked with Quique to design his 2002 TOC Yak. Quique has since done in different sizes and is very popular today- I assume that Wayne is still involved. The plans-dated October 1982- included instruction on building a foam ribbed wing. I thought that some of you might like to read or have a copy of this.

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