Part 7
Make a Giant Mama Bug Glider
Transcript of the narration below
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TRANSCRIPT
GIANT MAMA BUG GLIDER, PERFORMANCE ADJUSTMENTS, NEW DIRECTIONS

Making the Mama Bug Glider should be pretty easy if you made and flew the Baby Bug, and I’m assuming you have. Rough-cut the patterns close. Tape the ends to the remaining two big foam sheets. Be careful at this end to make sure all the pattern is on the foam. Cut the two long sides exactly on the solid lines, but not the ends with the tape.

 

Bend in the wing reflex by bending the elevons down. Pinch the paper hard to establish the bend, but only pinch right at the crease. Flatten a little and adjust it later. Once again use a thin pen or pencil and book to roll in the camber, with the edge of the book parallel to the front edge of the glider. Go 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. Again, there is a gage for right where the flaps start.

 

Cut off the ends with the tape to separate pattern from foam. Put the two halves together so the elevons are pointing up and convex wing curve is up, concave on the underside. I use the thinnest, clear tape I can find (1/2 inch, 12mm wide) colored here so it shows up on camera. I use 3 short pieces because I can’t manage 1 long piece. Tape the joint lengthwise and leave about ½ inch or 12mm un-taped at the trailing edge.

 

The wing connection is pretty flimsy. Taping the bottom will make it rigid, so flip it over. There’s a trick for taping in the dihedral, which is the slight upsweep of the wings for stability. With the wing bent like this, stick half of some tape to one side only. Bend back toward making the wing flat again, but not quite all the way flat. Holding that position, tape to the other side. When you flip it over right-side-up again and hold one side flat, the tip of the other side should be about 1 ½ inches or 39 mm off the table.

 

Check your wing camber again and roll in more if needed. Again if you start with a 45 degrees of elevon reflex up from the flat sheet it started as you’ll get good stability.

 

Tape the wire on with a small piece of tape so as much as possible sticks out. Adjust between stalling and diving by bending the wire more forward or backward. Add or remove tape if necessary.

 

MAMA BUG EFFICIANCY MODIFICATIONS FOR HAND FLYING

 

As with the Baby Bug, it might be best to reduce the elevon angle for hand and head flying. I find that it's harder to fly by hand if there's any stalling.

 

There’s another advanced modification that some very efficient, slow-flying wings have—such as in solar powered airplanes. This wing is convex, or bumped in front. But in back, it’s concave or dished in a little. Such a wing helps get the airflow from the top and bottom of the wing back together as smoothly as possible, so it’s efficient. I’m exaggerating here. And I know, the elevons already curve up in back. But I’m talking about something much more subtle and in the middle part of the wing where there are no elevons. With the glider right-side-up and the front tipped up a little, roll just a little bit of curve into the part of the wing without the elevons. It’s much less curve than in the front. You might have to readjust the weight in front if it stalls, or you might be able to push the elevons down a little more to counter stalling.

 

STAY IN TOUCH

 

So these are some pretty advanced adjustments. They’re complex because when you adjust one thing, you throw something else out of adjustment. But if you can work these variables, you’re starting to get a pretty good intuitive handle on aerodynamics.

 

Stay in touch. I like feedback, whether it’s to celebrate success or point out something that could be better. If you upload videos or pictures, I’ll link, with your permission. I plan to have one section for board flying, one for hand and head flying, one for aerial dog fighting and I already have a section about innovations and new branches of walkalong gliding.

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