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Old May 03, 2013, 09:36 AM
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United States, TX
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I also have very slightly more wing area than a Stryker. I've covered up the servo arm openings on the top of the wing. Probably will hardly make a difference though.

The alignment of the hinges in the hardpoints are difficult though. I've used pin-style hinges this time. You just drill a hole. Worked great on one of the ailerons, but the other seemed to push the hole off centerline, either above or below. Must have been a very hard grain in the middle to cause that. I'm not sure if that will affect operation or not. If so, then I need to make a whole new aileron for that side. Gawd this is becoming a real bitch. That must mean my boomer is a female.
(Sorry, just a joke).

My task for this weekend is to carve a rear fuselage form out of blue foam and then use it as a form for fiberglass. I'm going ahead with fiberglass because every other method stumps me.

I got in my pilot busts, so I am going to also work on my canopy/cockpit assembly this weekend also. I had a long canopy, so I'm going to have a pilot and a GIB (Guy in back). I know, this is usually used in the Navy, not the Air Force. So to be correct, I'd have to probably paint this a Navy color scheme. Or, it could be a 2-seat trainer, which would still be Air Force. I was kind of leaning towards a Vietnam-era color scheme, with brown and green camo on top and white underneath.
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Old May 05, 2013, 10:13 AM
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I have made more progress yesterday than I have in the last couple of weeks. There's a big push to get this plane done by the 25th of May so that I can take it with me on my cross-country trip back east to North Carolina, with a sweep through the gulf coast. I want to fly this plane at sea level right on the beach. I think it would perform brilliantly.
I will also try to bring a second plane, my modified Multiplex Easystar, which has ailerons and a souped up motor, and also flies very well.
Being foamies, both planes should survive the rigors of a long trip in the trunk, provided I have the room.

So anyway, yesterday I installed the ailerons and covered up the gap between the upper surface of the trailing edge and the leading edge of the ailerons with 0.07" plastic sheet (which will be painted over). I epoxied the motor mount in place. The motor itself will be movable, but the mount will be permanent. I covered up the rear fuselage opening and trimmed the canopy and decided where to put that. And this morning I calculated where the ideal CG would be on this plane, and it is 6.13" back from the root leading edge, which also happens to be right exactly where the Stryker had finger indents to test for CG. It makes sense that the CG would not change from the flying wing version of the Stryker. All I'm doing is adding a tail and a nose.

http://www.willingtons.com/aircraft_...vity_calcu.htm

I assembled the pilot and copilot last night. I have to shorten them up a little bit to fit under the low canopy, and then paint them with plastic model paints, and assemble the interior of the cockpit and paint that. Then epoxy the cockpit to the canopy, which will lift off for battery/radio access.

Also today, I am going to install all the servos and Y-connector. Maybe even get the elevator's pushrod installed.
On that, I did think about installing the elevator pushrod sheath in the middle of the 3-ply balsa fin to maximize aerodynamics, except that I needed to have the plane finished to see which wing half was lighter. Because then I could mount the elevator servo on that half to help balance the wing better (side to side). So I didn't initially know which fin would need the sheath pathway. I dunno...maybe I'm being too much of a perfectionist.

But one thing I've done before that I might do again is to hollow out a "canal" in the leading edge of the fin and run the pushrod sheath along that leading edge to get up to the horizontal stablilizer. Then I can cover it in silkspan (like the wing) to smooth it out and once it's painted, it won't be visible.

My goal is to be working on the plane's paint job by next weekend and then do some glide testing to test my balance point. I've found a couple of farmer's fields with fresh green alfalfa growing that should work perfectly for my flight testing.

The calculator also gave me my wing area. 380 square inches. (I didn't count the steeper sweep of the wing at the leading edge next to the fuselage. That would add about 6 square inches. Since I am currently at 27.5 ounces flying weight (heavy high-C lipo and heavy-ish metal-geared servos), my stall speed is now calculated at 22 mph now.

http://www.radiocontrolinfo.com/RCca...culator.php#WL

So that's pretty brisk. I'll have a flight envelope of 22 mph to 68 mph. It won't float as well as I had hoped, but that's because I had to go all out on this build and couldn't keep it simple.
However, considering the bad wind conditions here, I think it'll be okay for wind flying, and should have excellent wind penetration qualities.
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Old May 05, 2013, 06:14 PM
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Ready for paint...almost. Finally!
All servos installed. Motor installed. Electronics installed. Silkspan skin applied to nose and over servos to cover them. Elevator pushrod installed. All electronics tested.

One change. I can't use those cute pilot bust figures because the lipo comes up too far into the canopy area. So I'm just going to paint the canopy instead.

Next step, sanding and paint job.
I need to get olive drab, brown, and gold.
Then pushrods.
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Old May 11, 2013, 09:10 AM
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Okay, I got my motor shroud built. I found a water bottle that was just about the right shape. It's a little bigger than I wanted, but I could always find a smaller one later. So today I get to start my paint job. White on the bottom and camo on top, with a Vietnam-era color scheme.
I got my USAF decals in from Callie Graphics and they look great. By this time tomorrow, I'll have something I can take pics of, and the airplane will probably be finished tomorrow.

I am taking this plane on a cross country drive with me back east, so I can have plenty of wheat fields to choose from for flight testing. There is a small cavity in the nose underneath that I can cut the covering away from if I need nose ballast. But I think I'm pretty close to balanced with a lipo in the cockpit.

So more pictures are coming tomorrow!
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Old May 11, 2013, 09:11 AM
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I'm thinking this thread should almost be in the Pusher Prop Jet Models category, rather than parkflyers...
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Old May 11, 2013, 12:06 PM
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Livermore, CA
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Quote:
Originally Posted by builderdude View Post
I'm thinking this thread should almost be in the Pusher Prop Jet Models category, rather than parkflyers...
Seeing that most the WildWing Boomers were 6-7ozs flying as a parkflyer, your Boomer at over 20ozs would probably qualify as a pusher jet!

Just be sure you have plenty of room to land on the first couple flights.
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Old May 11, 2013, 07:49 PM
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OKAY Here she is!







I am not entirely pleased with the size of the bottle that I used as a motor shroud, but it will work until I find something better. And I am still working on getting the canopy to fit properly. But I am generally happy with the paint job. Tell you what, covering the foam with silkspan made a much nicer surface for painting than the foam itself provided.

I am going to start a new thread with this in the pusher prop jet page.

Thanks to Callie Graphics for the awesome decals!
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Last edited by builderdude; May 11, 2013 at 08:23 PM.
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Old May 11, 2013, 11:44 PM
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Livermore, CA
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Wow, that's one of the better looking Strykers I've seen.
Kinda looks similar to a Pushy-Cat.
I agree, post a thread on the Pusher Jet Forum.
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Old May 12, 2013, 08:41 AM
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Turns out I was way off about the stall speed.
I knew it didn't sound right. 10.44 oz/sf wing loading should be a LOT slower than 22 mph. Must have been a typo when I plugged it into this calculator:

http://adamone.rchomepage.com/calc_stallspeed.htm

Now I am getting 16 mph, and that's much more like it. That's pretty good actually. I have another foamie that I enjoy flying and have flown hundreds of times probably. It's my original trainer, a Multiplex Easystar. Except it has ailerons, a T-tail with larger surfaces, and a powerful outrunner. It's a proven flyer and it has a similar stall speed; maybe a little faster. Because that plane is an honest 2 pounds. I do have to give that one a little bit of room to fly, and don't try it around a lot of trees in a park.

But no worries. This is west Texas. Lots of open prairie. So there is plenty of room to land this baby.

While my rare earth magnets were being glued with epoxy for the canopy, they shifted, and so my canopy is off to the side in the back by about an eighth of an inch. Not enough to worry about, but slightly annoying just the same. Oh well, the canopy works great, I shouldn't complain.

I ran the pushrod for the elevator. I only have to do the pushrods for the ailerons and then the airplane is completed. I'll do a quick test of all systems and make sure it's ready to go. Then off to a field to maiden it, preferrably on a slightly breezy day. I'd like to keep the first flight a little short. I usually do. It builds up my confidence in the plane's abilities. If the short maiden flight goes well, then I go a little longer, and so on. Even though this is by far the toughest airplane I've ever built, nothing will survive a lawn dart landing. So I prefer to err on the side of caution.
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Old May 12, 2013, 09:17 PM
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Even though this is by far the toughest airplane I've ever built, nothing will survive a lawn dart landing. Quote
--------------------------

I built one that survived a lawn dart crash, straight in from about 200ft!!
A pusher Jet with a carbonfiber fuselage.
The plane was hardly even scratched, the nose was in about 4 inches, but the lipo broke loose and smooshed all up in into the nose pretty good. Not reuseable.


http://www.rcgroups.com/forums/showp...&postcount=163
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Old May 13, 2013, 09:18 AM
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125 views on my Pusher Prop Jet Models post on my Boomer and only one comment in all of that. One guy posted that the CG calculator that I've used for years has a Trojan Horse attached to it.

I access it with my work computer all the time, which is monitored by some of the best virus protection around, and it has never detected a Trojan Horse in the Stall Speed calculator, so I really doubt it. Why would someone attach a virus to something like that anyway?
I tried a different stall speed calculator and it was WAY off. That's where I got my original 22 mph stall speed figure on only 10.44 oz/sf, total BS. I used mine that I've always used and it came in at 16 mph, which is more believable.

Who knows?
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Old May 13, 2013, 09:20 AM
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Your carbon fiber lawn dart looks very nice, by the way.
What is it? Did you build the fuselage? Is it an ARF?
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Old May 13, 2013, 09:34 AM
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Quote:
Originally Posted by builderdude View Post
Your carbon fiber lawn dart looks very nice, by the way.
What is it? Did you build the fuselage? Is it an ARF?
I call it the Butcheti. Modeled after a ProJeti.
I designed the fuselage and made a mold.
I haven't done much with it since, as its a pain the make the fuselage halves and put them together.
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Old May 13, 2013, 02:59 PM
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Don't you have trouble getting a radio signal through a carbon fiber fuselage though?
Carbon is a semi-conductor and causes a shielding effect, unless you're using FM radio with the antenna wire in the wing or something.
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Old May 13, 2013, 06:44 PM
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I ran the antenna out of the fuselage, under the wing, out to the tip and the Berg rx I used has a mile range, so no biggie.
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