Flying a Lamp

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DynaSoar

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Yes it's April 1. No, this isn't a joke. Well it is, but the rocket's real. Feel free to yell at me for being too cheap as yet to buy a digital camera.

Back in The Old Days, we had to build our rockets with whatever we could find: toilet paper tubes, balsa stock stolen from the nests of Flying Model Pterydactyls, and table lamps. Since we have all this great stuff to build with these days, in order to build a rocket like in the old days, I had to build my own lamp first.

I started with an 18" BT70 and a standard E 70/50 size engine mount, put together as usual. The fins had to be big, for extra stability (on the table especially). I made them (four, 1/8", left square edged) shaped like a nice curvy Greek letter Psi. The bottom has to be wide enough to keep it stable with the lamp fixture on top.

Once all this was in place, I took a 36 x 4 inch sheet of 1/32 balsa and cut it into 18" strips, an inch or less wide, saving back some for later trimming and fitting. I glued a strip lengthwise against the clockwise side of each fin. It took many rubber bands to clamp the strips to the tube while they dried. These had to put stretched out, pulled over and snapped down on the stock, not rolled over it. It took some practice to get enough glue to cover the tube and balsa, but not so mucy that it oozed out when clamped. Lots of fast wping required. Marking the tube first using the strip to be fit helped.

Once dried, I sized up the gaps that were left and cut more balsa strips to fit. These had to be notched to go around the fins. The strips didn't have to fit very snuggly against the others. As a matter of fact it was harder to do this. The idea was to have small gaps, like paneling. These go away, trust me.

Once the entire body was covered with strips of balsa, I built a launch lug out of three 5" strips, forming a box or trough just big enough to fit a medium size rod. This got sanded into a rounded shape and glued on in between two fins.

Next, in when the elastic shock cord. To make this bird easily convertable, I did what I do with most of my birds, and put a snap swivel on the shock cord. (just consider being able to easily swap noses much less recovery devices -- it's handy).

I gave it fin and lug fillets on top of the paneling. The wood glue, being orange, was not pretty. Some light wood putty covered it sufficiently. It's still visible, but I couldn't go without fillets, and so...

For finishing, I slapped on the balsa nose and gave it 2 coats of Deft spray sanding sealer, and one good going over with fine and very fine sandpaper. I love this Deft stuff; very nice bottom finish. Over this went two coats (half a can!) of Minwax clear gloss polyurethane. This stuff is wonderful. It completely filled in all the gaps between the slats and left a glass-like finish, with no sanding.

Now for the lamp: I got an $8 lamp fixture from Lowes. It came in a package with 3 rubber plugs. It was intended to become a wine bottle lamp. What was important to me was it had a threaded stem on the bottom of the socket. It had no frame to hold the shade; I got a shade that slipped over the bulb. A goofy cloth shade with beads hanging from the bottom.

I got a 2 inch PVC pipe cap. This just happened to fit the body tube plus balsa paneling perfectly. I drilled a hole in it to fit the lamp socket stem. Then I wired up the socket with the wire through the cap, and tightened the fixture onto the cap.

Now, to make it convertable, I cut the lamp cord about 10 inches below the socket. For safety, I cut the wire so that one strand of each end was 3 inches shorter than the other (can't short together).

Finally, I ran the plug end of the cord up through the body, and spliced the ends of the wired together using wire nuts (those screw-on plastic caps that hold wired together safely, but can be taken off, and put back on, etc.). Slap the cap on the tube, slap the share on the bulb, and we have one flying table lamp.

To convert it takes less than a minute: take off the shade, pull up the cap, unscrew the wire nuts, pull out the wire, shake out the shock cord, and clip it onto the screw eye in the nose cone. Clip on an 18" (or larger, don't want to risk the fins on this) chute, and load a motor. I wouldn't try anything less than a D. It's not as heavy as you might suppose, but it's quite ungainly.

Have you ever realized how pretty the grain is on a nicely treated piece of balsa? Not much character, since it has no knots, but the grain has a nice pearlescent sheen. With the poly-u, the color is that of a blond elm or white pine. It turned out good enough to earn the Wife Stamp Of Living Room Furniture Approval. Despite the goofy shade. Or maybe because of. I don't question these things.
 

DynaSoar

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Originally posted by Stewart32
I gotta see this!
As soon as I can either arrange a camera from one of my lab mates, or CATO manages to beat the weather and hold a launch and THEY have one, I'll post it. I have a few other novel projects to show off. Like a Big Bertha thing with rear ejection with the chute built around the piston/engine tube, and my experiments with hollow fins made from folder styrene sheet. I may have spent 20 years away from rocketing, but I was thinking about it an awful lot. And it'd probably make an intersting picture seeing how much a 50 year old man jumps up and down just after flying his first rocket in 20 years. (Not really. I always jump up and down that much when I fly).
 
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