Part 4
Make a Baby Bug, Transport, Decorate and Teach
Transcript of the narration below
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TRANSCRIPT
MAKE BABY BUG GLIDER

 

I'm assuming you already built and flew a tumblewing and jagwing because the Baby Bug glider builds on that.

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Rough cut out a baby bug pattern close to the outside solid line. Cut especially close to the lines at the ends so you can center it on another small piece of foam—equal amount of foam sticking out from each side.

 

Tape the ends, but do not fold the tape over to the other side. Cut on the front solid lines and the back solid lines but do not cut off the ends where the tape is holding the foam to the pattern, yet. Color the tape if it helps you remember not to cut the ends.

 

As you did with the jagwing, use a book so the elevons and the dashed line peek out and push the paper down to make folds. Rotate 90 degrees and bend down again on the middle line.

 

Take it out and pinch to really establish the folds, but only pinch right at the fold. Pinching a wider area of foam would weaken and warp it. Flatten all these folds a little. You’ll get the exact angles later.

 

As you saw with the jagwing, curving the front of a wing yields greater lift, and with this Baby Bug design it’s important that you get it right.

 

With the foam side down, paper pattern side showing up, I use my fingers and a thin pen or pencil to roll the camber into the front of the wing. Just rolling over wing won’t curve it. But if you tip up the glider over a book… and line up one front edge of the glider parallel with the book edge…then rolling does push the foam and pattern against the curve, making a permanent curve.

 

I roll up to the edge of region 1, tip up more and roll more in region 2, and tip up the most and roll the most and hardest on region 3, right to the edge. Do the same for the other half of the wing.

 

Eventually you can experiment with different wing cambers, but to start this wing gage can help you tell if you have a good curve, if you cut very carefully with the tips of a good pair of scissors. Advance slowly around the curve. It’s designed to measure curve right here only, where the elevons start and parallel to the center line. Try to get it close, you can do more adjusting when the pattern's off.

 

I’m going to mark the foam side as TOP to avoid confusion again, and separate the pattern off by cutting on the solid lines on the sides. Save the paper pattern for another glider. It’s good to measure the camber again with the pattern off. Remember the gage measures the curve where the flap begins, parallel to the center line. You can measure from the top, too. If it doesn’t have enough curve, you can still roll more in.

 

There’s also a gage for the elevons this time. Start out with 45 degrees bent up from the flat sheet you started with. Again you can measure from the top or bottom. Eventually you can experiment with less angle for greater flying efficiency, but right now 45 degrees gives great stability. For dihedral the middle should be bent enough that when you press the top of one wing down, the tip of the other wing should be at least ½ inch or 13 mm above the table.

 

 

Pull out another short wire and—with a tiny piece of tape—attach it to the foam so it sticks out in front as much as possible. I tape to the glider top. Bend in a little hook to the front so you don’t poke someone.

 

PITCH ADJUSTMENT

The Bug gliders take more adjusting for pitch control. At one extreme you have stalling in peaks and valleys. Adding more weight to the front will correct stalling. At the opposite extreme the glider dives. Cutting off front weight will correct diving.

 

For micro adjusting, there’s an easier way than adding or subtracting weight. Levering the wire way out like this affects the glider just like adding more front weight. Bending it way back like this is just like cutting off weight.

 

Other things affect pitch, too. Adding more camber, or curve, to the wing also has an effect similar to adding weight. And lowering the elevons is like adding weight, too.

 

Having so many variables is confusing at first. As you work with it you’ll get used to it. When model airplane people adjust for flight they call it “trimming.”

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