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Building Tips and technical articles. => 1/2 A building. => Topic started by: John Crocker on July 06, 2007, 06:05:51 PM
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Had the day off, no kids, buddies were tied up, so I built a new model. Made plenty of built wing kits, but never one from scratch. So here is my "Approaching Storm". 24" wingspan, 132 sq". Think it is 15" long. Little nose heavy, the CG is about 1" in front of the leading edge of the wing, but will see how she flies before I change anything. Wing is similar to a baby clown to save weight and covered in Monokote. Tail is a rip off of a Ringmaster, but I like it so who cares. Will post up flight info soon.
(http://i52.photobucket.com/albums/g3/Adduckted/approachingstorm.jpg)
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What does it weigh, John? Very nice.
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No idea. All the scales I have access to are at work. Should have been lighter, I messed up on the nose and used too much plywood. Luv using CA cause you can finish the model in a day, but once its on there, its staying.
I'd say weight wize its on par with the dead Phoenix IV, which flew like a scalded dog. If I'm right, with the airfoil it should fly better, and with the CG further forward, do tighter loops. We'll see.
Finally figured out my issues with the Norvel. I had put "medium" gas lines on it. Was not getting a good suction I guess, cause when I switched to small it ran great.
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CG further forward will = bigger loops, not smaller. It will be more stable. With the CG where you indicate, it should groove like it's on rails.
I tend to place CG much further back, significantly behind the LE. Makes my planes very sensitive, but as an old combat flier that's what I'm comfortable with.
I predict you'll be adding some lead to the tail after you fly it a time or two. Maybe with less ply. on the nose it would come out nearer to what you want. Still, a good looking airplane.
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Looks like you're using muffler pressure. With that you could mount the tank on the inboard side and shorten the nose.
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Well, learned 2 new things today. CG is backwards from what I thought, and you can mount an engine on the other side of the fuse.
As far as the weight goes, I'll probably just make the elevator wider. Its 9" wide now, always liked the look of a wide tail, on planes and on women. ;D
Don't want to change the engine though. Kinda scared bout going blind for the needle. When I was 8 I watched my Pop cut the top of his index finger off on a Cox that was running backwards and slipped out of hand, dang Master Airscrews are sharp.
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I think Don meant for the TANK to go on the inboard side ("under" the engine) to get it out of the way so you could move the engine back, still on the outboard side. Better than adding lead to the tail to move the CG back. I agree with you, wouldn't want any setup where the needle is "blind".
And if you think Masters are sharp, you oughta see an APC--I believe you could cut out balsa parts with it! I bloodied my finger just flipping the prop. I now blunt the knife-edge with sandpaper before I ever put an APC prop on an engine.
--Ray
--Ray
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The trick to flipping an APC is to put your fingertip on the front of the prop, not around the trailing edge. The better trick is to use a heavy leather glove. I have had one or two engines where I was comfortable flipping an APC without glove.
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The trick with ANY 1/2A is to use an electric or spring starter. Hand flipping is for the birds.
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Electric starters are for pansies. Spring starters are only good for starting Coxes in the right direction.
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Mark me up as a pansy then, cause I don't have the patience or the knee and ankle strength to stay squated for an hour trying to get one to start with a spring or flip. I LUV my electric starter.
Small prime, 2 turns, hit it with the starter and open the throttle till she starts. Works EVERY time
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I've considered using a lightweight folding table for a 1/2A runway just because I have difficulty getting down and back up again. So far, I've never owned an electric starter. I have on occasion flipped into frustration and I've gotten cut a few times.
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Flipping a Cox engine is an exercise in frustration. Put in a head prime, hook up the battery, turn the prop backwards to vertical, give it a hard hit with your gloved finger, and launch.