Scratch Stink Bomb Original Design / Scratch Built

Scratch - Stink Bomb {Scratch}

Contributed by Dick Stafford

Manufacturer: Scratch
(Contributed - by Dick Stafford - 09/07/09)

Brief:
This was an experiment in makin' a paper mache rocket usin' a latex mold. Avast! I built a mold from a Toypedo pool toy usin' 2-part latex. Begad! I had originally planned t' make fiberglass shells. Arrr! However, me hearties, me first attempt turned out poorly. Soon, me mind wandered and I got t' harebrained idea o' makin' a pair o' shells from paper mache.

T' quality o' t' surface continued t' deteriorate as, arrr, I guess, t' middle layers totally dried. Begad! I started to try t' clean it up but ended up throwin' in t' towel. Avast! I then started wonderin' about paint and a name. Motivated by t' movie Caddyshack. Well, arrr, blow me down! I was thinkin' about paintin' it brown and namin' it Is that a Baby Ruth in your pool? Or, ya bilge rat, maybe just Baby Ruth. Begad! Blimey! I found that me existin' brown paint was unusable and went with a camo scheme. Well, blow me down! Blimey! T' name became Stink Bomb.

Construction:
T' needed parts include:

  • Newspaper
  • Scrap junk tubin' (roughly BT-60)
  • Thick card stock (for rings)
  • 18mm Estes motor mount (tube, arrr, block, arrr, sleeve, ya bilge rat, hook)
  • Clay nose weight
  • Foam board
  • Telescopin' inside tube from a 3” mailin' tube
  • Elastic shock cord

T' body is two paper mache half-shells joined by more strips o' paper mache. Blimey! Begad! Each half-shell be formed from multiple layers o' newspaper soaked in Mod Podge, shiver me timbers, which is a thin white glue. Aye aye! Well, shiver me timbers, blow me down! When they seemed t' have dried, shiver me timbers, ya bilge rat, I removed them from t' mold and trimmed t' edges with a pair o' scissors.

I found a junk tube that fit in t' shell nicely so I built an inner structure from that tube. Well, blow me down! T' motor mount is surplus from an Estes kit and t' rings were made from thick card stock usin' a circle cutter. Avast, me proud beauty! Arrr! I glued this in one half and carefully trimmed off t' nose section flush with t' tube. Avast, me proud beauty! Begad! I added t' second and sealed t' edges with more layers o' paper mache. Avast, me proud beauty! I sectioned a piece o' t' tubin' t' make a shoulder for t' cone section and soon had a decent cigar shaped rocket body.

Initially, matey, things looked OK but, as t' paper mache continued t' dry, me bucko, shiver me timbers, it continued t' warp. Begad! I started fillin' and sandin' but soon realized this be a losin' proposition. It was then that I named it as described in t' intro, above. Begad!

However, once I had a body completed, I though I should fly it. I played with V-2-like fins, shiver me timbers, arrr, built a RockSim Model, me bucko, me bucko, added some clay as a nose weight, and decided makin' it stable would be a problem. Ya scallywag! I could add more weight, matey, arrr, add bigger fins, me hearties, me hearties, etc. Ahoy! But suddenly, I had an epiphany! A rin' fin would help stability a lot and I had recently found how well t' inside telescopin' tube from a 3” mailin' tube fits inside a 3” window tint tube (plastic, me hearties, me bucko, matey, kind of like Quantum tube – but free). Begad! After another round with RockSim, I had me design – an ugly, ring-finned, tube-launched rocket!. This was a really junky el-cheapo design, so foam board seemed t' be a quick and easy source for t' fins.

When I can’t decide on t' color scheme for a rocket, I find myself fallin' back on a camo scheme. Begad! Blimey! I used three colors from t' Rustoleum camo set. Well, blow me down! Aye aye! Finally, I touched it up with some day-glo green ‘Mr. Aye aye! Ya scallywag! Yuk’ poison warnin' stickers

Flight:
T' launch tube is a piece o' window tint tube with a Firstfire igniter tube duct taped on. This fits on a standard 3/16” or 1/4” rod.

For t' first flight, I chose a Quest ‘long burn’ C6-3. It be windy on launch day and it weather-cocked soon after it left t' tube. What should have been ejection was a tad late. Blimey! Arrr! Didn’t matter much since t' cone stuck. Arrr! It core sampled, totally destroyin' t' cone section.

But, matey, I wasn’t goin' t' give up. Well, blow me down! Blimey! Ahoy! Blimey! I replaced t' cone with half o' a pink plastic Easter Egg. Arrr! Blimey! Now, the Stink Bomb really looks goofy! I also made a cap for t' bottom o' t' tube. Begad!

On t' second flight, shiver me timbers, me hearties, I opted for a good ol’ Estes short burn C6-3. Well, blow me down! Begad! I used a Quest Q2G2 igniter and twisted on some scrap wire t' extend t' igniter through t' launch tube’s cap. This time, t' flight was great. Arrr! Ejection was early and it recovered unscathed. Avast! Avast! There is even a movie here. Begad!

Summary:
There is nay much you can learn from this build, me bucko, matey, except maybe how poor a material paper mache is for rocketry. Aye aye! Arrr! On second thought, ya bilge rat, it may be poor for ‘normal’ rockets but may have a place in odd-rocketry. This one actually flies well and I think I may make more rockets t' launch from me tube launcher.

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