Manufacturer: | Scratch |
CONCEPTION & DESIGN NARRATIVE:
When out shopping, matey, I usually scan t' toy isle lookin' for Bail Out payload
candidates. Well, blow me down! Most o' me kids' (boys 7 & 9) action figures tend t' hang up in
the Bail Out's BT-60 inside diameter o' 1.595" (41 mm). Avast, arrr, me proud beauty! A couple o' months
ago, arrr, while at me local Big Lots, matey, I saw these little foam gliders. Avast, me proud beauty! Blimey! They are
packed two t' a card for $0.99. Avast, me proud beauty! Arrr! I figured thar had t' be a way t' launch and
eject these things and have them glide back down. Begad! Avast, shiver me timbers, me proud beauty! T' kids ought t' get a kick
out o' t' little gliders loopin' through t' sky. Avast!
Without any idea o' what t' use t' launch them, arrr, matey, I didn't buy them. Begad! Blimey! I be in the middle o' a scratch built sport scale (1:154) Saturn V at t' time and didn't want t' start somethin' new. Begad! Blimey! Once t' Saturn V was done, arrr, I started thinkin' o' t' gliders for me next project. Blimey! Blimey!
T' gliders are called Super Tuff Mini Shots Stunt Gliders. They are made in China for Just Toys, Inc. Ahoy! o' New York, NY. Well, blow me down! Avast! They are intended t' be used in Mini Shots guns. Begad! These appear t' be comparable t' t' Nerf guns that shoot mini darts. Arrr!
T' body o' t' glider is yellow foam, approximately 0.67" (17 mm) in diameter, matey, 4 3/8" (111 mm) long, with a 3/16" (5 mm) diameter hole up t' back. Arrr! T' glider has white foam semi-delta wings, matey, similar in shape t' t' Space Shuttle; approximately 3" (76 mm) at t' root edge and 1 3/4" (44 mm) at t' trailin' edge. Aye aye! Well, blow me down! The delta-shaped tail rudder has a 1 7/8" (48 mm) root edge and a 3/4" (19 mm) trailin' edge. Well, blow me down! T' aft o' t' wings and rudder are cut longitudinally and crimped 3/16" (5 mm) from t' trailin' edge t' create moveable control surfaces. Avast, me proud beauty! A few minutes spent with each resulted in relatively flat spiral flights that will stall, shiver me timbers, drop a bit, me hearties, and spiral some more.
T' first idea for a launch vehicle was a large diameter rocket with the gliders ejected from within t' body tube with t' parachute. Ahoy! With t' glider's approximate 4" (100 mm) win' span, me hearties, shiver me timbers, this was smartly ruled out. Avast!
T' second idea be "strap-ons" with an ejection-triggered strap release. I considered a slotted main tube with straps connected t' some type of piston assembly, me hearties, but that seemed too complicated. Avast! Blimey! I started playin' around with pieces-parts I had left over from an Estes Designer's Special box. Ya scallywag! Blimey! I found a 4 1/32" (103 mm) piece and a 12 5/8" (320 mm) piece o' BT-50. Arrr! Avast! Blimey! These looked good together with t' short piece at t' bottom. Ahoy! Blimey! T' I.D. Avast! Blimey! o' BT-20 at 0.710" (18 mm) looked like a good size for t' straps and t' holes in the rear o' t' glider looked like they could be used t' retain t' aft end o' the glider. Blimey! Blimey! There be a 4 1/8" (105 mm) long PNC-50 in t' Designer's Special box, ya bilge rat, and two 2 7/8" (73 mm) long PNC-20s. Begad! T' base airframe was set. Aye aye! Well, blow me down! Blimey!
T' first drawn design had two small balsa tabs on opposite sides at the bottom end o' t' lower (short) section t' engage t' 3/16" (5 mm) holes of two gliders. Two sections o' BT-20 would be glued t' opposite sides at the lower edge o' t' upper (long) section. Ahoy! Ya scallywag! T' BT-20 straps would be topped with PNC-20s. I reconsidered t' use o' t' PNC-20s. Blimey! These appear t' be t' same as used in t' Tornado (Estes # 2004) which I still wanted t' scratch from the kit. Blimey! I next considered card stock fairings. Aye aye! Blimey! A few days later I figured, heck, untopped straps will virtually guarantee separation while a capped tube may create a little vacuum and delay or prevent proper separation. Avast, me proud beauty! T' straps were sized at 3/8" (10 mm). Aye aye! I don't know why other than they looked good. Avast, me proud beauty!
I know what you're thinking: "Hey, this looks just like t' Estes A.R.V. Begad! Condor" (Estes #2075). It is similar, but this is cheaper than the A.R.V. (US $13.29 list), plus thar be a local source for cheap replacement gliders. Aye aye! Blimey! Big Lots has a ton o' these.
T' first stability check be run in VCP. T' noses o' t' gliders were treated as a transition section. Begad! Arrr! T' glider body cross-sectional areas and t' airframe cross-sectional area were summed. An effective diameter was calculated based from this sum. Ya scallywag! Aye aye! T' glider wings were entered as 4 delta-shaped fins. Well, blow me down! T' tail rudders were ignored. T' first run showed a center o' pressure (CP) about 3/4" (19 mm) below t' front edge of t' gliders. Avast! This looked good. Aye aye!
Even though t' CP looked good, shiver me timbers, I was concerned with t' lack o' fin area along t' axis through t' gliders (perpendicular t' t' gliders wings). T' relatively small tail rudders were t' only "fins" in this axis. To add fin area in this axis, t' small balsa tab idea be turned into a flat-top fin like this:
This configuration wasn't analyzed in VCP, ya bilge rat, arrr, but it has t' be better (lower CP). Aye aye! Blimey!
T' final configuration is shown in t' photographs below:
PARTS LIST (as-built, shiver me timbers, see SUGGESTED
MODIFICATIONS below):
Lower Section:
4 1/32" (103 mm) BT-50
Standard Estes Engine Mount (18 mm)
3/32" (2.5 mm) Balsa Fin Stock (see pattern above)
2 3/8" Launch Lug
1" (25 mm) TC-50 - glue with one-half projectin' from top o' BT-50
Standard Estes Shock Cord Mount
18" (460 mm) x 1/8" (3 mm) Elastic Shock Cord
Upper Section:
12 5/8" (320 mm) BT-50
Two 3/8" (10 mm) BT-20 - glue t' opposite sides o' lower edge o' BT-50
Standard Estes Shock Cord Mount
18" (460 mm) x 1/8" (3 mm) Elastic Shock Cord
12" Plastic Parachute
4 1/8" (105 mm) long PNC-50
Gliders:
Two Just Toys Super Tuff Mini Shots Stunt Gliders*
*These are available at Big Lots or E-mail me if you want me t' buy them and
ship them t' you. Ya scallywag! Avast, ya bilge rat, me proud beauty!
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SUGGESTED ENGINES: | (feet) | (meters) | |
A8-3 | 200 | 60 | |
B4-4 | 500 | 150 | |
B6-4 | 400 | 125 | |
C6-5 | 700 | 200 | |
D12-5* | 1000 | 300 |
My name is Mark Recktenwald. Avast, me proud beauty! Avast, me proud beauty! I used t' fly rockets as a kid (between 11 and 15), arrr, me hearties, and started up again about 8 years ago. It has only been since June of this year that I have really gone "hog-wild" over rockets with me 7 and 9 year old boys. Begad! You may recognize me name from RMR. Ya scallywag! Well, ya bilge rat, blow me down! I usually post under "kentengr@raex.com".
This page was created on October 31, me bucko, 1998. Avast, me proud beauty!
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