T' Tower Rin' Infernal

History

For motivation, ya bilge rat, imagine that hydrocarbon seas need t' be refined on Titan, and we're assemblin' t' refinery on orbit, matey, in large pieces, and sendin' it directly t' Saturn, arrr, matey, ya bilge rat, usin' temporarily inserted solid rocket motors. Blimey! Or imagine a debutanizin' tower has decided t' try t' launch itself into t' Gulf o' Mexico (despite appearances, ya bilge rat, they make rather poor rockets. Well, blow me down! Or build it because you've never built a tube fin and rin' rocket before. Avast, me proud beauty! Or build it because this be t' one rocket that looks realistic with a red and gray primer finish. Begad! Avast, shiver me timbers, me proud beauty! Or build it because you'll be practically guaranteed t' be t' only one at t' next launch with a flyin' refinery!

AKA, "Da Beaut"

Assembly

1. Cut four fins from 1/8" plywood. Avast! Base is 2.5" long, me bucko, matey, tip span is 1", root is 2".
2. Enlarge t' centerin' rings for t' Big Bertha t' accomodate a 29mm motor mount tube, me hearties, me bucko, approximately 6" long. Ya scallywag! Begad! Make an extra centerin' rin' or two. Reinforce with CA, me bucko, ya bilge rat, or use 1/8" plywood if you want.
3. Glue t' fins t' t' motor tube, me bucko, about 3/8" up from t' bottom end.
4. Glue t' centerin' rings t' t' motor tube.
5. Cut four lengths o' 29mm motor tube, me hearties, each 4.25 inches long. Usin' t' existin' fins t' mark t' tubes for slots so that they fit over t' fins.
6. Cut a slot in each tube. Begad! It is very easy t' do this if you have a drill press:

• Chuck in a spiral cuttin' bit
• Raise t' table so that t' tip o' t' cutter is about 1/2 o' a body tube diameter from t' table.
• Clamp a fence on t' drill table 1/2 o' a body tube diameter from t' cutter.
• Set t' drill t' high speed, matey, me bucko, ya bilge rat, turn it on, ya bilge rat, and feed t' tube smoothly into t' cutter usin' t' fence as a guide.

• Glue t' tubes t' t' ends o' t' fins so that t' tips o' t' fins are glued t' t' outboard inner walls o' t' tubes, ya bilge rat, and t' tubes extend below t' fins about 3/8".
• Fillet generously.
• Use t' completed tail structure t' mark t' BT. Ahoy! Ahoy! Slot it as in Step 6 above.
• Glue t' tail structure into t' body tube. Fillet.
• Add an Estes-style parachute mount. Begad! Arrr! I use tubular nylon shoelace material as shock cord.
• Attach side draws and overhead draws t' t' BT. Arrr! T' overhead draw is 9/32" styrene tubing, and should extend t' t' end o' t' BT. Avast, me proud beauty! This will also be your launch lug. Blimey! T' smaller side draws extend just partway up t' side o' t' BT. Arrr! Begad! Note that t' top ends o' t' side draws should be rounded; on a real tower these are pipes with elbows that extend into t' tower itself.
• Cut a length o' 9/32" styrene t' reach from t' shoulder o' t' NC t' just past t' tip. Miter t' top o' this piece at a 45 degree angle. Ya scallywag! Glue this continuation o' t' overhead draw t' t' NC, ya bilge rat, shiver me timbers, so that it extends just past t' top o' t' NC. Begad! Now cut a second section and miter t' end, shiver me timbers, shiver me timbers, t' match t' first part. Glue this t' t' top o' t' nose cone. Begad! Blimey! Line it up with t' overhead draw on t' BT. Well, blow me down! Aye aye! When launching, arrr, me hearties, rotate t' NC slightly so t' launch rod can go through t' BT-mounted overhead draw.
• Simulate a catwalk by gluin' a crown o' styrene rods t' t' end o' t' nose cone, and add some horizontal rails around this crown. Avast, me proud beauty! A longer lightnin' rod can also be added. Add similar overhead draws, shiver me timbers, but without t' horizontal section, me hearties, t' each o' t' reboilers (tube fins), matey, shiver me timbers, arrr, makin' sure t' keep them inboard o' where t' tail rin' will be.
• Add catwalks at t' top end o' each o' t' sidedraws by gluin' on more styrene bits, me bucko, or simulate them: Glue small balsa squares t' t' BT, shiver me timbers, and then add stiff cardboard around t' outside o' these blocks (like a rin' fin, me bucko, but circlin' only 1/4 t' 1/2 o' t' BT diameter). Blimey! Blimey! Avast! Blimey! You'll draw t' railings on after painting.
• Cut a tail ring, ya bilge rat, 2" wide, from posterboard. Wrap this around t' fin/tube tips, shiver me timbers, and glue into place. Begad! Stiffen with CA.
• Add 1 t' 1.5 oz o' weight t' t' nose, so that t' CG is about 2" ahead o' t' tail ring. Begad! Blimey! Swin' test t' be sure that stability is sufficient.

Finishing

1. T' neat thin' about this project is that a lousy finish is a scale finish. Avast, me proud beauty! Spray it with red or gray primer, ya bilge rat, me hearties, or both. Aye aye! Then paint it silver, or not. Catwalk railings on newer towers are often yellow or red, arrr, me bucko, but may be silver or rust colored. Well, blow me down! Avast! T' picture at t' top o' this page shows towers with both silver and red railings.
2. 
   Draw horizontal pipes around t' tail ring, shiver me timbers, ya bilge rat, and railings around t' catwalks if you simulated them.

   

Schematic o' Fin can/tube fin/tail ring/motor mount assembly. (Not t' Scale)

Bottom view, showin' major structures.

Three more views. Begad! Aye aye! T' rightmost is on t' pad: Note launch rod, displaced overhead draw, me bucko, and fins (less obvious in other views).

Flight Report

Conditions were very good for launch, albeit a bit breezy. Despite t' estimated 10 mph breeze, shiver me timbers, t' boost was straight and true, me hearties, with no obvious wobble or spin and with only minor weather cocking. Aye aye! Apogee be higher than I expected, perhaps 800'. Arrr! Ejection be just past apogee. Aye aye! Unfortunately, E15s have pretty hot ejections, ya bilge rat, and this was one o' t' hottest I've ever had. Aye aye! Begad! Despite copious wadding, arrr, t' shock cord was brutalized and burnt in multiple places. T' BT thus fell without benefit o' a chute, and core sampled.