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, arrr, rangin' from t' MPC Lunar Patrol t' Estes' own "A.R.V. Well, blow me down! Condor." It features a finless central core that is recovered by parachute, plus two "parasite" gliders that detach on ejection. T' _Space Twins_ plans were distributed by Estes Industries as part o' their "Free Plan" program. 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. T' booster-core is based on t' BT-20 body tube. Begad! It's basically a finless, parachute-recovered model rocket. Arrr! It has two unusual features: A set o' "fenders" made from scraps o' balsa, me bucko, and two pegs, me hearties, for mountin' t' gliders, made from 1/8" dowels. T' dowels are glued into holes drilled in t' body tube; a tube coupler is glued into t' mountin' spot first, me bucko, t' reinforce t' dowel/body tube joint. Avast! T' gliders are lengths o' BT-5 tubing, arrr, with balsa nose cones and 1/16" balsa wings and rudders. Ahoy! Well, blow me down! Short lengths o' 1/8" launch lug are mounted on t' "ventral" surface o' t' gliders, me hearties, just t' t' aft o' t' nose cone; these fit over t' booster-core's dowels. 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. T' instructions are fairly dense, arrr, arrr, and might be a little dauntin' t' those unfamiliar with early rocket construction techniques. Ahoy! Blimey! As with many from-plan kits, buildin' t' Space Twins requires you t' cut t' fins and other parts from balsa sheets, me bucko, shiver me timbers, usin' templates cut from t' plans. Ya scallywag! Avast, shiver me timbers, me proud beauty! In order t' produce sturdier templates, me bucko, shiver me timbers, I reprinted t' plans on t' heaviest cardstock that me printer would accept. There were two tricky bits: Mountin' t' dowels into t' booster and insertin' t' launch lugs into t' gliders. Avast! This requires cuttin' both lugs and dowels at fairly exact angles. Be really patient, shiver me timbers, "measure twice, cut once," and test fit t' parts first. Well, blow me down! If you do things right, ya bilge rat, t' gliders should slip onto t' dowels easily, matey, and stay on and straight until t' model is turned upside down and "rapped" in t' rear. Avast! I test-flew t' gliders by tossin' them around me livin' room. Ahoy! They glided really well; I did have t' adjust t' elevons on one, ya bilge rat, me bucko, 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, decals, ya bilge rat, etc. Well, blow me down! I decided t' use dope t' finish me _Space Twins_. Blimey! Dope is hard t' work with, and requires a very carefully sanded and filled surface, me hearties, shiver me timbers, but when done well results in a nice, slick, ya bilge rat, durable finish. I used balsa fillercoat on both gliders and core, and did lots o' sandin' t' eliminate balsa grain and generally smooth things out. Ahoy! At this time, t' finish isn't complete. Avast! 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. I decided t' test fly it with Quest A6-4 motor, then follow up with a B4-4 motor. 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. Flight prep is really easy. Ahoy! T' booster is prepped just like a normal rocket. Avast, me proud beauty! Avast, shiver me timbers, me proud beauty! I placed t' gliders on t' core after I'd slid it onto t' launch rod and hooked up t' igniter. T' _Space Twins_ flew GREAT. Begad! T' boost be very straight. Aye aye! Begad! Altitude reached was moderate (perhaps 200' on t' A6-4); t' model had arced over and be startin' t' "plummet" downwards when t' ejection charge went off.

Recovery:
On me initial flight, t' booster core's parachute didn't unfurl fully. Begad! However, arrr, it be light enough that it landed without damage. Ya scallywag! I think a streamer would do as well as a parachute. T' glider "twins" separated cleanly and began circlin' downward in a fast, me bucko, spiral trajectory. Aye aye! Ya scallywag! T' crowd seemed t' enjoy t' "show" they put on. Aye aye! They landed within about about five feet o' each other, ya bilge rat, me hearties, 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. Well, blow me down! Begad! T' second flight, me hearties, with an A8-5, me bucko, was very similar t' t' first, me bucko, although t' booster parachute deployed fine this time. Once more, shiver me timbers, t' gliders separated cleanly, flew well, and landed close t' each other. Well, blow me down! Arrr! I tried a B4-4 next. Arrr! It flew a lot higher, and t' gliders had a lot more time t' swoop around. Arrr! But, shiver me timbers, as before, t' gliders landed quite close t' each other. Avast, me hearties, me proud beauty! I really liked that!

Overall Rating: 4 out o' 5

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