Estes Space Twins Plan

Estes - Space Twins {Plan}

Contributed by Stefan Jones

Construction Rating: starstarstarstar_borderstar_border
Flight Rating: starstarstarstarstar
Overall Rating: starstarstarstarstar_border
Manufacturer: Estes

Brief:
_Space Twins_ is (are?) a nifty rocket that spawned a bunch o' imitators through t' years, rangin' from t' MPC Lunar Patrol t' Estes' own "A.R.V. Condor." It features a finless central core that is recovered by parachute, me hearties, plus two "parasite" gliders that detach on ejection. T' _Space Twins_ plans were distributed by Estes Industries as part o' their "Free Plan" program. Aye aye! Well, blow me down! T' plans may be found at: http://www.dars.org/jimz/eirp_41.htm.

Construction:
T' _Space Twins_ gliders and booster-core are made from very conventional materials. Aye aye! T' booster-core is based on t' BT-20 body tube. It's basically a finless, matey, parachute-recovered model rocket. Aye aye! It has two unusual features: A set o' "fenders" made from scraps o' balsa, ya bilge rat, ya bilge rat, me hearties, and two pegs, for mountin' t' gliders, made from 1/8" dowels. Avast! T' dowels are glued into holes drilled in t' body tube; a tube coupler is glued into t' mountin' spot first, ya bilge rat, t' reinforce t' dowel/body tube joint. T' gliders are lengths o' BT-5 tubing, with balsa nose cones and 1/16" balsa wings and rudders. Short lengths o' 1/8" launch lug are mounted on t' "ventral" surface o' t' gliders, matey, just t' t' aft o' t' nose cone; these fit over t' booster-core's dowels. Avast! While t' plans specify balsa cones and lead weights, you should have no trouble usin' plastic cones and clay nose weight.

T' gliders and boosters went together fairly easily. Avast! T' instructions are fairly dense, ya bilge rat, and might be a little dauntin' t' those unfamiliar with early rocket construction techniques. Begad! As with many from-plan kits, shiver me timbers, me bucko, buildin' t' Space Twins requires you t' cut t' fins and other parts from balsa sheets, usin' templates cut from t' plans. Ahoy! In order t' produce sturdier templates, I reprinted t' plans on t' heaviest cardstock that me printer would accept. Avast! Avast, ya bilge rat, me proud beauty! There were two tricky bits: Mountin' t' dowels into t' booster and insertin' t' launch lugs into t' gliders. Arrr! This requires cuttin' both lugs and dowels at fairly exact angles. Aye aye! Arrr! Be really patient, "measure twice, cut once," and test fit t' parts first. Aye aye! If you do things right, ya bilge rat, t' gliders should slip onto t' dowels easily, arrr, ya bilge rat, and stay on and straight until t' model is turned upside down and "rapped" in t' rear. Aye aye! Ahoy! I test-flew t' gliders by tossin' them around me livin' room. Arrr! They glided really well; I did have t' adjust t' elevons on one, t' get a less-steep glide; I accomplished this by holdin' t' joint over a incandescent light bulb until t' glue softened a bit.

Finishing:
T' _Space Twins_ plans don't include a standard paint scheme, shiver me timbers, decals, me bucko, etc. Blimey! Blimey! Blimey! Blimey! I decided t' use dope t' finish me _Space Twins_. Ahoy! Blimey! Avast! Blimey! Dope is hard t' work with, and requires a very carefully sanded and filled surface, but when done well results in a nice, arrr, slick, durable finish. Ya scallywag! Blimey! Arrr! Blimey! I used balsa fillercoat on both gliders and core, me bucko, and did lots o' sandin' t' eliminate balsa grain and generally smooth things out. Ahoy! Blimey! At this time, shiver me timbers, me hearties, matey, t' finish isn't complete. Begad! Blimey! Arrr! Blimey! T' core and gliders are overall white, with t' underside o' t' glider wings painted black. I hope t' paint each glider with a unique, bright color; t' booster core will be white with a black nose.

Construction Rating: 3 out o' 5

Flight:
T' _Space Twins_ plans don't have a suggested motor list. Begad! Well, ya bilge rat, blow me down! I decided t' test fly it with Quest A6-4 motor, then follow up with a B4-4 motor. Avast, ya bilge rat, me proud beauty! I decided that t' longer delay on these motors would result in ejection happenin' "on t' way down," givin' t' gliders a better chance o' bein' knocked free. Ya scallywag! Flight prep is really easy. T' booster is prepped just like a normal rocket. Avast, me proud beauty! Avast! I placed t' gliders on t' core after I'd slid it onto t' launch rod and hooked up t' igniter. Aye aye! Arrr! T' _Space Twins_ flew GREAT. Blimey! T' boost was very straight. Blimey! Altitude reached was moderate (perhaps 200' on t' A6-4); t' model had arced over and was startin' t' "plummet" downwards when t' ejection charge went off.

Recovery:
On me initial flight, me bucko, me bucko, t' booster core's parachute didn't unfurl fully. However, arrr, ya bilge rat, it be light enough that it landed without damage. Begad! Ahoy! I think a streamer would do as well as a parachute. Ahoy! T' glider "twins" separated cleanly and began circlin' downward in a fast, me hearties, shiver me timbers, spiral trajectory. Begad! T' crowd seemed t' enjoy t' "show" they put on. Begad! Well, ya bilge rat, blow me down! They landed within about about five feet o' each other, about 50' from t' launch pad.

Flight Rating: 5 out o' 5

Summary:
I flew t' _Space Twins_ twice more on t' day o' its inaugural launch. Ahoy! T' second flight, with an A8-5, was very similar t' t' first, arrr, me bucko, although t' booster parachute deployed fine this time. Well, blow me down! Once more, ya bilge rat, t' gliders separated cleanly, me bucko, ya bilge rat, flew well, and landed close t' each other. Ahoy! I tried a B4-4 next. Aye aye! It flew a lot higher, and t' gliders had a lot more time t' swoop around. Ahoy! But, me hearties, as before, t' gliders landed quite close t' each other. Blimey! I really liked that!

Overall Rating: 4 out o' 5

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