DON’T LET YOUR BREAD LOAF!
or, tales of what to do with stale bread besides make pudding.
by Burl Finkelstein
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What comes to ones mind when looking at a hard French bread lying on the counter?
Rockets, of course!
After flying toast in the form of saucer ToasTites, on numerous occasions I had a hunger to fly more challenging baked goods. The first attempt was a thin 3/4 pound French bread loaf with Matzo fins. My son had a friend visiting who openly expressed his disbelief in my ability to make the bread fly. The gauntlet was thrown; it flew in my back yard on a 24mm E-9 about 1-1/2 hours later. (se photo, below). It survived but my son and his friend ate it as soon as it landed so there was no second flight or evidence of the success.
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I knew I had to make another bread rocket someday and chronicle the construction to aid the public in techniques for ecologically sound recycling of stale baked products. A friend was planning to put on a “Dumpster dive” rocket building at the Atlanta NAR club, Soar 571. A competition event to make rockets of cast off non-traditional materials gave me the perfect occasion to debut a mid-powered loaf.
Construction began over a month from the launch date when I would not let anyone eat the one-pound Italian bread that was growing hard on our kitchen counter. My thought was that a hard crust was a good replacement for a layer of fiberglass. Therefore, really letting it harden and should be a good thing. This turned out to be my first mistake, because the loaf became overly brittle by the time I built the rocket. Experience has determined that one to two week old stale bread has ideal flight properties. Over one month old bread has too much aging on the airframe and may be subject to fatigue failures.
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Parts laid out in preparation for construction. For fins I preferred rye toast for its high structural strength and good elastic modulus. But the plans had to change when the pickings were only one slice of rye and one slice of pumpernickel. I was left to improvise and use enriched white bread for two of the fins. A cautionary note: use bread of like density, size and aerodynamic drag for opposite fins!
The plan was to make the full one pound loaf into all bread 29mm powered, parachute recoverable rocket.
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Photos show the construction stages and the exclusive use of non-toxic hot melt glue. (CAUTION THE WRITER IS A TRAINED EXPERT IN THE USE OF HOT MELT GLUE AND DOES NOT SUGGEST USING IT ON ROCKET CONSTRUCTION BY AMATEURS!)
First the airframe is cut crosswise with a sharp bread knife. The tip of the loaves boat tail was cut off to allow a place for the motor mount to protrude. My next step was a mistake in retrospect. On bread rocket 1, I drilled a hole thru the airframe. This time I tried to core it by forcing a 29mm motor tube thru the brittle dry bread.
"Ouch", I said as the side blew out of the loaf near the mid body-coupling joint while I was forcing the coring tool thru the body. The rocket was already going to be heavy and I had to add more weight of hot melt to the airframe to repair the damage. After gluing in the motor tube and drilling the nose cone for the parachute bay, I glued the tubes to the bread with copious amounts of hot melt. Alignment of the airframe was checked while the gluing was done and crumbs were used to shim the tubes.
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The next step was the "Thru-the-crust" fin mounting. “Thru-the-crust” is a mandatory method because fins glued to the crust will just pull off the crust at the slightest amount of aerodynamic loading. Slots were cut using a serrated bread knife with a fish pattern. I rooted down 1/4-inch to 3/8-inch under the crust to get a solid fin root.
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Hot gluing the previously toasted fins was next. I used caution to balance rye with pumpernickel and white toast to white toast. At this point the loaf was starting to look more like a flying object than something to fill with meatballs, cheese and sauce. Launch lugs were made from loops of copper wire and glued into holes in the crust. I dribbled some glue from the lugs around the rocket surface to provide a better anchor for the lug. This reinforcing step was similar to icing a hot cross bun.
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The 36-inch parachute was made from at large trash bag and fit nicely into the parachute bay. The shock cord was anchored to a piece of Kevlar cord tied around the aft end of the motor tube. My plan was to have the aft end come in “fins up”, to avoid fin damage. Nose weight was chewing gum to keep the rocket edible. I chose a F20-4 as a conservative first flight motor to keep the vehicle from loafing. It really wanted a G motor, but I want to wring out any bugs first, (or before the bugs set in).
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IT FLIES!. It flew a good but slightly wavy flight to 150 or 200 feet. Everyone held his or her breath as it arced over and headed for the ground. But alas the 4-second delay was about 1/4 second more than the time it took to reach the ground. CRUNCH!
The chute was not necessary as in the end it had CRUMBLE recovery!
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