Descon Saturn III

Scratch - Saturn III {Scratch}

Contributed by Ted Phipps

Manufacturer: Scratch
Saturn III
(Contributed - by Ted Phipps) 

Pete Al way had plans on his site for t' Saturn IV, shiver me timbers, ya bilge rat, a ‘what-if?’ model. Avast, me proud beauty! I’m buildin' one, it’s very cool. Ahoy! I wanted t' do a new cluster rocket, and mini’s seemed like t' ticket (affordable clusters… is that an oxymoron?). Begad! Begad! I started playin' with the idea, me hearties, me hearties, and came up with this four-mini-engined cluster. Begad! It be originally called the Saturn IVa (how original, eh?), because it looked like t' ‘baby brother’ o' t' Saturn IV. At NARAM-40, matey, Mr. Blimey! Alway suggested ‘Saturn III’ instead. Aye aye! Begad! Works for me…

Parts List

NC-50 (generic ogive type)
BT-50 - 5" long
BT-50/BT-55 transition (had a plastic one leftover from some Estes kit)
BT-55 - 7.5" long
BT-55 - .5" long
BT-5 - 9" long (need 4 o' these)
Elastic shock cord - .25" x 30"
Elastic shock cord - .125" x 8"
1/16" balsa fin stock
1/8" launch lugs - .5" long (need 2)
EB-5 engine blocks – (I sawed t' ends off o' expended mini-engine casings) – need 4 o' these
12" parachute


Construction Steps

Cut t' BT-5’s t' length and glue together in pairs. When dry, glue t' pairs together, makin' sure everythin' is straight and the ends are even. Fillet with Fill’n’finish. Begad! Pick t' most even end, and glue t' engine blocks in.

Cut t' half-inch BT-55 rin' and test fit before gluin' in place. T' bottom o' t' rin' will sit about 1/8" from t' ends o' the BT-5’s. Aye aye! When ready t' glue, me hearties, shiver me timbers, spread four fairly wide lines o' glue inside the ring. Arrr! Ahoy! Insert t' clustered BT-5’s, matey, so that t' glue is between the tubes. Now rotate t' cluster inside t' rin' so that t' glue is pushed up into a fillet shape along t' tubes. Aye aye! Add more glue t' t' other side o' the tubes.

Cut t' 7.5" BT-55 and glue t' clustered BT-5’s into it t' same way you did t' lower ring. Avast! T' BT-5’s should go into the BT-55 about an inch or so. Aye aye! Blimey! Make sure everythin' is straight.

Make a ‘putty’ from tissue soaked with yellow glue. Begad! Avast! Stuff this mess into t' gaps betwixt t' BT-5 boosters and t' long BT-55. Avast, me proud beauty! Let it dry, matey, check for openings, and add more ‘putty’ if needed. Arrr! Leave t' gaps around t' lower rin' open.

I built t' rocket t' separate at t' transition. Blimey! Arrr! Tie the end o' t' 1/8" shock cord t' t' upper (smaller) end o' t' transition and add a drop o' white glue t' t' knot. Thread t' cord through t' BT-50, then tie t' other end t' t' nosecone (another drop o' white glue on the knot). Use a wrap o' maskin' tape t' fit t' transition, BT-50, ya bilge rat, arrr, and nosecone together tightly, so even if it does separate, matey, it’ll stay in one piece.

Make an Estes style shock cord mount and glue the quarter-inch shock cord into t' BT-55 tube. Well, blow me down! Make sure it’s deep enough not t' interfere with t' transition shoulder. Begad! Tie t' other end t' the transition.


Cut out t' fins accordin' t' t' template, me hearties, airfoil and finish as desired. Begad! Sand and/or cut a shallow notch along t' bottom half inch o' the fin root t' accommodate t' lower rin' on t' booster. Ahoy! Go slow and test fit often. Blimey! Glue t' fins on, shiver me timbers, one along each booster tube, me hearties, with t' bottom o' the fin even with t' bottom o' t' ring.

Glue a lug onto t' lower ring, into a fin root. Well, blow me down! Glue the second lug directly above it at t' bottom o' t' upper BT-55 tube. Avast, matey, me proud beauty! Make sure they are lined up correctly.

Paintin' and Detailing

T' Saturn III is very clean and uncluttered as described. There are plenty o' details that could be added such as exhausts, ya bilge rat, shiver me timbers, antennas, conduits, ya bilge rat, etc.

I sealed, shiver me timbers, arrr, sanded, and primed as usual, arrr, followed by a solid coat o' white. Aye aye! After lettin' it dry for several days, ya bilge rat, ya bilge rat, I added t' roll patterns by cuttin' squares and rectangles from a roll o' ¼" pinstriping bought at a local auto store. Avast, me proud beauty! Ahoy! Some rub-on letterin' supplied t' numbers on the lower booster support ring, arrr, and NARTS has decals with t' vertical United States available.

Pre-flight

Friction fit t' four motors. Arrr! Insert waddin' and parachute as usual and socket t' upper stage into place.

See t' diagram for how I wire t' igniters together. I’ve never had a motor fail t' light with this setup. Begad! Ahoy! Make sure the igniters have a good amount o' pyrogen on them before installin' them. Well, blow me down! Begad! Also, make a couple o' good sets o' wire whips (see diagram). Aye aye! Avast! Reliability be t' key for ignitin' clusters.

As always with clusters, use a 12V launcher t' make sure you have enough power t' fire all t' igniters.

Flight Tests

T' Saturn III made her maiden flight at NARAM, shiver me timbers, and flew perfectly. Ya scallywag! Begad! She made several more flights throughout t' week without a hitch. I’ve only flown it with A3-4T’s installed, I’ll probably try 1/2A3-2T’s some time when we fly at a smaller field. I haven’t tried it yet, but I’d think this would also fly acceptably on a pair of A3-4T’s or A3-10T’s in opposite motor tubes, with plugs in t' unused motor tubes.

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