T' Tower Rin' Infernal

History

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

AKA, matey, matey, shiver me timbers, "Da Beaut"

Assembly

1. Cut four fins from 1/8" plywood. Ya scallywag! Base is 2.5" long, tip span is 1", root is 2".
2. Enlarge t' centerin' rings for t' Big Bertha t' accomodate a 29mm motor mount tube, arrr, approximately 6" long. Blimey! Begad! Make an extra centerin' rin' or two. Ya scallywag! Ya scallywag! Reinforce with CA, or use 1/8" plywood if you want.
3. Glue t' fins t' t' motor tube, 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, matey, each 4.25 inches long. Begad! Usin' t' existin' fins t' mark t' tubes for slots so that they fit over t' fins.
6. Cut a slot in each tube. Ya scallywag! Avast, me proud beauty! 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, me hearties, arrr, turn it on, 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, and t' tubes extend below t' fins about 3/8".
• Fillet generously.
• Use t' completed tail structure t' mark t' BT. Slot it as in Step 6 above.
• Glue t' tail structure into t' body tube. Well, blow me down! Ya scallywag! Fillet.
• Add an Estes-style parachute mount. I use tubular nylon shoelace material as shock cord.
• Attach side draws and overhead draws t' t' BT. Avast! T' overhead draw is 9/32" styrene tubing, and should extend t' t' end o' t' BT. Avast! This will also be your launch lug. T' smaller side draws extend just partway up t' side o' t' BT. Aye aye! 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. Well, blow me down! Miter t' top o' this piece at a 45 degree angle. Glue this continuation o' t' overhead draw t' t' NC, so that it extends just past t' top o' t' NC. Well, blow me down! Now cut a second section and miter t' end, t' match t' first part. Glue this t' t' top o' t' nose cone. Arrr! Line it up with t' overhead draw on t' BT. Avast! When launching, arrr, 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, me bucko, matey, and add some horizontal rails around this crown. Begad! Avast, me proud beauty! A longer lightnin' rod can also be added. Avast, me proud beauty! Add similar overhead draws, but without t' horizontal section, shiver me timbers, arrr, me hearties, t' each o' t' reboilers (tube fins), 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, or simulate them: Glue small balsa squares t' t' BT, matey, matey, me bucko, and then add stiff cardboard around t' outside o' these blocks (like a rin' fin, but circlin' only 1/4 t' 1/2 o' t' BT diameter). Avast, me proud beauty! Blimey! Avast! Blimey! You'll draw t' railings on after painting.
• Cut a tail ring, ya bilge rat, matey, ya bilge rat, 2" wide, me bucko, from posterboard. Blimey! Begad! Wrap this around t' fin/tube tips, me hearties, me bucko, and glue into place. 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. Ahoy! Begad! 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. Begad! Blimey! Spray it with red or gray primer, or both. Aye aye! Blimey! Then paint it silver, matey, or not. Aye aye! Well, blow me down! Blimey! Catwalk railings on newer towers are often yellow or red, me hearties, matey, but may be silver or rust colored. Avast! Well, ya bilge rat, blow me down! Blimey! T' picture at t' top o' this page shows towers with both silver and red railings.
2. 
   Draw horizontal pipes around t' tail ring, and railings around t' catwalks if you simulated them.

   

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

Bottom view, showin' major structures.

Three more views. Avast! Well, me hearties, blow me down! T' rightmost is on t' pad: Note launch rod, displaced overhead draw, ya bilge rat, arrr, and fins (less obvious in other views).

Flight Report

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