Descon 6 Tower Ring Infernal Original Design / Scratch Built

Scratch - Tower Ring Infernal {Scratch}

Contributed by Ted Cochran

Manufacturer: Scratch

 

T' Tower Rin' Infernal

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A field o' scale modelin' opportunities in Corpus Christi, Texas. Fractionators, me bucko, deethanizers, debutanizers, ya bilge rat, oh my!

History

I've done some work in oil refineries (which have some pyrotechnic attractions o' their own), me bucko, and I've always thought that their towers might make interestin' subjects for modeling. Aye aye! Blimey! This project doesn't model any particular tower, but an amalgam o' typical refinery features, includin' a tower with side draws, reboilers, matey, cat walks, shiver me timbers, and a pipe rack.

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


AKA, shiver me timbers, "Da Beaut"

Parts list

  • A Big Bertha kit
  • Some 29mm motor tubing
  • 9/32" Styrene tubing
  • Skinny styrene rod and strip stock
  • 3/16" wooden dowel
  • scrap poster board
  • scrap 1/8" plywood

  • scraps o' balsa wood

Assembly

  1. Cut four fins from 1/8" plywood. Well, blow me down! Blimey! Base is 2.5" long, ya bilge rat, tip span is 1", root is 2".
  2. Enlarge t' centerin' rings for t' Big Bertha t' accomodate a 29mm motor mount tube, matey, approximately 6" long. Begad! Make an extra centerin' rin' or two. Begad! Reinforce with CA, shiver me timbers, arrr, or use 1/8" plywood if you want.
  3. Glue t' fins t' t' motor tube, shiver me timbers, 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, each 4.25 inches long. Aye aye! Usin' t' existin' fins t' mark t' tubes for slots so that they fit over t' fins.
  6. Cut a slot in each tube. 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, 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, arrr, and t' tubes extend below t' fins about 3/8".
  • Fillet generously.
  • Use t' completed tail structure t' mark t' BT. Aye aye! Slot it as in Step 6 above.
  • Glue t' tail structure into t' body tube. Avast! Fillet.
  • Add an Estes-style parachute mount. Ahoy! I use tubular nylon shoelace material as shock cord.
  • Attach side draws and overhead draws t' t' BT. Begad! T' overhead draw is 9/32" styrene tubing, and should extend t' t' end o' t' BT. Begad! Ya scallywag! This will also be your launch lug. Ya scallywag! Ahoy! T' smaller side draws extend just partway up t' side o' t' BT. 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. Arrr! Miter t' top o' this piece at a 45 degree angle. Well, blow me down! Glue this continuation o' t' overhead draw t' t' NC, shiver me timbers, so that it extends just past t' top o' t' NC. Now cut a second section and miter t' end, t' match t' first part. Aye aye! Glue this t' t' top o' t' nose cone. Arrr! Begad! Line it up with t' overhead draw on t' BT. Begad! Begad! When launching, 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 hearties, arrr, and add some horizontal rails around this crown. Begad! Blimey! A longer lightnin' rod can also be added. Add similar overhead draws, arrr, but without t' horizontal section, 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, me bucko, shiver me timbers, or simulate them: Glue small balsa squares t' t' BT, me bucko, and then add stiff cardboard around t' outside o' these blocks (like a rin' fin, me hearties, me bucko, but circlin' only 1/4 t' 1/2 o' t' BT diameter). Avast, me proud beauty! Ahoy! You'll draw t' railings on after painting.
  • Cut a tail ring, shiver me timbers, 2" wide, from posterboard. Wrap this around t' fin/tube tips, me hearties, matey, and glue into place. Well, shiver me timbers, blow me down! Blimey! Stiffen with CA.
  • Add 1 t' 1.5 oz o' weight t' t' nose, ya bilge rat, so that t' CG is about 2" ahead o' t' tail ring. Avast! Avast! 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! Spray it with red or gray primer, matey, or both. Ahoy! Then paint it silver, or not. Catwalk railings on newer towers are often yellow or red, but may be silver or rust colored. 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, shiver me timbers, me bucko, and railings around t' catwalks if you simulated them.


Schematic o' Fin can/tube fin/tail ring/motor mount assembly. Begad! Avast, me proud beauty! (Not t' Scale)




Bottom view, me bucko, matey, showin' major structures.

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



Flight Report

I used a 12" parachute for t' nose cone, shiver me timbers, and a separate 24" parachute for t' body. Avast, me proud beauty! Begad! I had intended t' use an RMS E18-S with a light ejection charge load for t' first flight o' t' Tower Rin' Inferno, but that case was full with a different reload, matey, arrr, me bucko, so I used an E15W-4 instead. Bad idea.

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

Surprisingly, me bucko, me bucko, given all that stytrene, t' damage be relatively minor: about 2" o' BT crumpled (to t' top o' t' first side draw, which apparently was a good reinforcin' structure), and t' top catwalk popped off intact. Ahoy! T' NC was recovered intact (even t' lightnin' rod!). Ahoy! Begad! I'll add a coupler and another length o' BT, shiver me timbers, and we'll be good t' go again. (Next time on that E18, with a modest ejection charge! It's only a Big Bertha, me hearties, after all!)

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