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"Any-delay" rockets
Hello All,
I thought of a “new” (actually, it’s a new application of an old idea) concept for a self-maximizing, arbitrary-length recovery system deployment delay system, which would be very useful for model rockets and for boosted darts, including scale and competition models: Looking at pictures of the classic Quercetti catapult-launched missiles (I have attached photographs of some of them below, for anyone who may be unfamiliar with these Italian-made toys), it occurred to me that their simple, non-pyrotechnic (and non-electronic) streamer and parachute deployment system--their rockets used both recovery devices--could also be employed in standard model rockets (and in boosted darts). Moreover, the Quercetti recovery device deployment system, which automatically activates only at or very near the peak of the rocket's trajectory, would enable a model rocket or a boosted dart to reach its highest possible altitude (using *any* given motor) automatically, without any delay charge in the motor. Also: Such rockets could use [1] plugged motors, [2] zero-delay booster motors (which could be allowed to self-eject [or to vent their forward burn-through gases rearward through vents; both arrangements would add to the model's upward momentum]), and [3] re-loadable motors that are configured as "sans delay and ejection charge" rocket glider motors. Now, the Quercetti parachute (or streamer) deployment system operates as follows: The body tube has a large, flush, integral "hatch" in its side, which is hinged at the rear. The parachute (or streamer, depending on which Quercetti missile--the Tor, Tor II, Orion, or Jupiter--the model is) is folded and packed inside the body tube, and the hatch is closed. Then: The hatch is secured closed by a long, thin, strake-like lever, which is hinged into the model at its (the model's) front end (below the nose cone, and just above the forward edge of the hatch); when the strake-lever is folded down to lie atop the rocket's body, running down its length to a scale-like nozzle below the tail fins (this nozzle serves as a handle for launching the model), it locks the hatch shut. As well: A small, flat vane at the rear end of the strake-lever (in most Quercetti missiles, it "fairs" smoothly into the side of the scale-like plastic nozzle) holds the lever against the rocket's side during ascent, utilizing the aerodynamic force on the vane to hold it in place (before launch, the launching person's thumb holds the vane [and thus the lever] in place). When the missile slows to a stop, at the peak of its rubber catapult-launched flight, the lever--due to the lack of aerodynamic pressure on its rear vane, the momentum of the mass of the vane which makes it swing forward, and the slight mechanical pressure of the packed parachute or streamer that wants to pop the hatch open--swings forward, opening the hinged hatch and deploying the recovery system. In addition: Particularly with the larger Quercetti missiles, such as the Tor and Tor II (which are about BT-50 size--the streamer-equipped Jupiter is about ~T15 [15 mm] tubing size), the slight internal mechanical pressure from the packed parachute isn't necessary; the larger, more massive strake-lever/vane has ample momentum to swing forward of its own accord to open the model's parachute hatch. But even the smallest Quercetti missiles, if their strake-lever hinges are kept clean and freely-moving (which isn't hard, as the hinge area is easy to get to and clean out if necessary), reliably deploy their parachutes or streamers. Below are attached pictures of a few Quercetti missiles:
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR Last edited by blackshire : 03-12-2017 at 04:14 AM. |
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How do they fare with weathercocking? Rockets can experience a pretty broad parabolic trajectory and a fairly high airspeed through apogee.
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I love sanding. |
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Quote:
The only deployment failure occurred due to my error--I'd packed the parachute too tightly (it wasn't a "neat" packing), and it pushed against the hatch hard enough to create too much friction in the strake-lever's forward hinge, so that it didn't swing far enough forward to un-latch the hatch. But the missile suffered no damage, as its nose cone was made of rubberized plastic. In addition: A completely “stock” (un-altered) Quercetti missile could be flown as a boosted dart; its nozzle (with the strake-tip vane “flush” against the nozzle) could simply fit into the top of the rocket-powered booster, either sliding free at booster motor burnout (due to differential drag) or—with a slightly tighter fit, if desired or needed—being “popped out” by the booster’s motor ejection charge (or by its forward burn-through gases, if the booster used a zero-delay booster motor and tumble recovery).
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR Last edited by blackshire : 03-12-2017 at 08:21 AM. |
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A buddy of mine had some of these when we were kids....this was at least 35 years ago. I remember them flying quite well, but not too high. About like a BT-50 rocket with a 1/2A motor.
They did fly a lot higher than a typical pump-up water rocket and were far less messy.
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When in doubt, WHACK the GAS and DITCH the brake !!! Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't ! Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY. ALL systems are GO for MAYHEM, CHAOS, and HAVOC ! |
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Quote:
The "messy" component was one of the big reasons to fly them...in the summer, of course.
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I love sanding. |
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Quote:
__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR |
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