Saturday, February 14, 2009

The Build Stack

Currently under construction:
Orbital Transport

Kits coming:
Madcow Mozzie

Need repairs, have parts:
RNGbane the Valkyrie
Gilder 2 (lost tail fin yesterday while glide testing)

Need repairs, parts coming:
Gauchito
Alexi Leonov

Planned scratch builds:
13mm saucer, 3" diameter
29mm saucer, 12" diameter
24mm saucer, 8" diameter (smaller than the previous one; designed for use as a lower stage)
18mmx2 cluster*
24mm machbuster**
13mm superroc***
13mm minimum diameter streamer duration / general flying rocket****
13mm WAC Corporal / Tiny Tim (design from NAR Guidebook)
MMX monocopter

Kits, not yet ordered, plan to build stock:
Dr. Zooch Saturn 1B
Dr. Zooch Saturn V
Apogee Heli-roc

Kits, not yet ordered, plan to modify:
Big Bertha*****
Estes Patriot (payload section and bulkhead)
Apogee Aspire (18mm adapter and 3/16 launch lugs)

Not very likely, but dream of getting:
Madcow Patriot
Madcow Momba or Cowabunga
Semroc Orbital Transport
Estes D-Region Tomahawk

*18mmx2 cluster: A pair of 18mm tubes about 18" long, inside an oval-squished 29mm tube 13" long. For a sort of dual deployment: a B6-4 with a streamer for slowing and stabilization in one tube, and a B6-6 with a parachute for lower, safer deployment in the other.

** 24mm Machbuster: A simple upscale of MMD, with a 24mm mount for a G80 or F55 (or similar), plywood fins, and one hell of an attitude. It'll also be a little longer, probably 18", for more stability with small fins.

*** 13mm superroc: a way to use up some of that 13mm tubing and tube couplers. For competition, 1/4A superrocs can be 25-50cm (10" to 20")(one 18" tube plus a 4-caliber NC max); 1/2A superrocs can be 50-100cm (20" to 39")(two 18" tubes plus NC max) and A superrocs 75-150cm (30" to 59")(up to 3 18" tubes plus NC max). I'll probably go for a 36" body and 2" NC, reaching 96 cm, good for 1/2A and A competition, yet not too long to carry and store.

**** 13mm general flier: currently my 13mm fleet is a monocopter, the medium-width but heavy Jinx, the fat but light Gauchito, the heavy and possibly unstable Cohete, and the heavy, short, and non-aerodynamic Rokit. None are thin, light, and sleek; i.e., good for streamer duration contests, general flying on 1/4A and 1/2A motors, or use as an upper stage (the Jinx gets burned by the staging blast because it's too fat). This'll be a basic, 10" long, 13mm model with swept fins and a largish streamer. It'll also be able to fly on MMX in my yard if I wish.

***** Big Bertha: Modified to take 29mm motors. Or maybe only 24mm motors, like Es and Fs. Like here, or here. I won't try a G (2900+ feet; questionable on a 3000' AGL waiver) or H (a mile plus, definitely illegal in CT), but an F will get me 2000 feet or so, okay on a windless day at CATO, and an E will get me about 1400' (E30, E9) to 1600' (E15). A D12-5 gets 930 feet with ejection right at apogee; 18mm composite D21-4s and D10-5s perform similarly for three to five times the cost. As a comparison, the recommended C6-5 gets 540 feet (500 at ejection; the recommended delay is 4 secs), 260 on a B6-2 or -4; 250 on a B4, and about 100 on the not-recommended A8-3 and A10-3T. (All simulations performed on the modified RASP-93 running on my calculator). I'll replace the stock 18" chute (12 fps descent; gone on anything above a C) with a 12" chute (17 fps) or 8" (26 fps; 250 foot drift from 1000 feet in a 5mph wind) chute, or even a large streamer for E and F flights. All fins will be reinforced with lots of wood glue; I'll put both 1/8" and 1/4" lugs on it.
I think I'll call it the Badass Bertha.

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