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Old Oct 04, 2013, 02:52 AM
Builder / Pilot
Joined Oct 2013
17 Posts
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049 Scratch build RC - Anyone have experience?

Scratch building a small rc glider with an old 049 I found hiding in the garage.

Basing my design on this: http://www.outerzone.co.uk/plan_file...mal_Magnet.pdf


I want to make the surfaces, surface positions, dyhedral, incedence, engine position, and thrust match the plans.

For the fuse, I'm using a fiberglass pushrod for a tail boom, mounted into layered into a balso/ply profile pod fuse, which will house a 1oz fuel tank, 1 micro tower pro servo for aileron, 1 micro tower pro servo for elevator, receiver and battery pack. Possibly landing gear to match the plans as well depending on weight.

Wing will be cut from 2mil corro [long grain], with bottom flutes cut to take shape of 8 balsa ribs and 1/2" basswood spar. [Airfoil similar to plans, yet flat bottom ribs and open bottom wing.]

Tail surfaces from 1/6"balsa, lightweight hinge tape for elevator, covered with monokote OR painted and clearcoated.


Anyone have experience with small rc like this? weight restrictions things to watch for? left / right thrust? I'm curious how the motor will do with no vacuum pushing the fuel into the engine, tank is just venting to open air... Will post pics as I start building, if I don't hear anyone warning me of anything I'm cutting the wing ribs and fuse shape tomorrow!

Wish me luck!
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Old Oct 05, 2013, 08:44 AM
Registered User
Canada, ON, Cottam
Joined Jan 2012
1,256 Posts
I have an old timer similar to that. Uses a Babe Bee, 15 1/2 oz. 47" x 6 1/2" wing. Your coro wing will definitely be heavier. Flies ok, had to add a bit of downthrust so I didn't have to change trim when the motor quit. Kind of a boring plane, going to the swap meet in Nov. rudder and elevator. If you are using the undercambered wing, keep the speeds down or it will tuck under in dives. Should work nice.
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Old Oct 05, 2013, 12:13 PM
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E-Challenged's Avatar
United States, CA, Garden Grove
Joined Oct 2000
11,692 Posts
Short nosed model may tend to be tail heavy requiring nose ballast after covering. Mount battery pack and RC gear as far foreward as practical. Keep tail parts and fittings light. Easier to add a little weight to tail if needed than to correct tail heaviness.
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Old Oct 05, 2013, 01:11 PM
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United States, CA, Thousand Oaks
Joined Sep 2010
193 Posts
What aspeed said. Keep your wing loading under 12 oz./ft^2 and you should be OK. I'd like to comment on your use of a fiberglass pushrod for a boom. Make sure you find one that is really stiff, otherwise you'll get an up-close demonstration of "trim-tab effect." I discovered this as a teenager many years ago, when I used a fiberglass arrow shaft on a small, Baby Bowlus I threw together.
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Old Oct 05, 2013, 04:49 PM
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Joined Jan 2008
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Take a look at the slightly redesigned Thermic 50-x construction article in the recent issue of Flying Models. If you want to do a pod and boom, look around for the Thermic 50-X and Thermic 72. I prefer the earlier Jasco designs over the later Jetco designs.
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Old Oct 07, 2013, 12:28 AM
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Joined Dec 2007
1,218 Posts
Since we now have very light micro RC gear you don't have to use sticks, sheet the fuselage to get a long lasting strong model. Your building a free flight plane that had less power than a 049 and rain on gas with less rpm. The plan isn't designed for acro so your engine will do fine and with the thick cambered airfoil you will have a floater. So min. 3 deg down thrust with at least 2 deg right thrust.
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Old May 27, 2014, 11:16 AM
Builder / Pilot
Joined Oct 2013
17 Posts
You guys are awesome thank you! i need to learn to pay attention to the threads i start.

Pod and boom fuse was wayyy too heavy, and the wing came out like garbage...

made a few changes - used an arf wing from a FLING hlg - great lift with the right speed, fuse still too heavy.

Made new fuse with carbon fiber boom, fiberglass gave me some serious trim tab effects - no fun! New fuse is much lighter, but still too heavy with full battery/servo/receiver loading. I'm on the hunt now for a Spektrum block with the inline servos, with a 1s lipo it should lighten it up enough to fly well.

NEVER RAN THE MOTOR on the fuse, only did hand launch tests, none of which very successful. Once I finish lightening the fuse again, I'll give it a shot with some down and right thrust.

Thanks again guys! i'll get some pictures up today
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Old May 29, 2014, 12:07 PM
Measure thrice, mark twice...
ahrma_581's Avatar
United States, AZ, Ajo
Joined Jun 2012
124 Posts
Quote:
Originally Posted by BuiltByPeter View Post
I'm on the hunt now for a Spektrum block with the inline servos, with a 1s lipo it should lighten it up enough to fly well.
Those micro bricks are made for 1-1.5 oz electric foamies. Might work for glide/trim on the size plane you're building, but suspect control authority would be pretty underwhelming under power (even with a 1/2a). Think you'd be better off with a couple 9 gm servos and a mini receiver of some type with a smallish nimh battery.
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Old May 29, 2014, 09:19 PM
"Unnecessary Necessity"
coriolan's Avatar
Canada, BC, Vancouver
Joined Sep 2006
5,759 Posts
+1 on the Spektrum ar-6400 brick not being adequate for a glow powered model, the linear servos would not stand the vibrations for long. There is others DSM2 systems like the "Orange" R415 coupled with HK-5320 servos would be a better option:
http://www.hobbyking.com/hobbyking/s..._Receiver.html
http://www.hobbyking.com/hobbyking/s...c_0_075kg.html
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