Scratch Crazy Train Original Design / Scratch Built

Scratch - Crazy Train {Scratch}

Contributed by Peter Stanley

Manufacturer: Scratch
(Design this Spaceship Submission - by Peter Stanley - 09/03/06)

Diagram

3D

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Crazy Train parts list

  • 1  8" BT-80 body tube
  • 1  .75" BT-80 coupler
  • 1 .25" BT-80 coupler
  • 1 2.59" diameter bulkhead
  • 1  PNC-80BB nosecone
  • 4  5.75" BT-20 body tubes
  • 4  .75" BT-20 couplers
  • 4  9" Mylar parachutes (originally spec’d with streamers, but later changed)
  • 4  BT5-BT20 centerin' rings (used as engine blocks in 18mm tubes)
  • 2  3"x3"x.75" sheets o' balsa (for constructin' tail cone)
  • 1 small sheet of  3/32" (.09375") balsa for 8 small fins and optional mirror mount
  • 4  .75 inch wooden balls (can be purchased at a crafts store)
  • 1  2" x 3/16" launch lug
  • 4 small screw eyes
  • 4 medium snap swivels
  • 4  12" 100lb strength Keelhaul®©™ thread
  • 4 6" pieces o' 1/8" shock cord
  • Bulkhead Template (PDF)
  • Fin Wrap Template (PDF)
  • Forward Fin Template (PDF)
  • Rear Fin Template (PDF)
  • Tail Cone Template (PDF)
  • Mirror Mount Template (PDF)
  • Peter Stanley's Word DOC Submission

 

Crazy Train buildin' instructions

  1. Cut t' tubes t' lengths needed. Aye aye!
  2. Prefinish tubes with 2 sessions o' fill n' finish and sanding.
    I get good results usin' bondo putty spreaders. Well, blow me down! Well, blow me down! You can cut them t' 1/2 wide strips and smear t' fill n' finish directly into t' spirals. Begad! Ya scallywag!
  3. Cut t' fins. Blimey! Use t' provided templates as guides. Blimey! T' grain on the forward fins should follow t' leadin' edge. Blimey! Ya scallywag! I did this also on t' aft fins, but would now suggest makin' t' grain follow t' bottom edge. Well, shiver me timbers, blow me down! In this particular configuration I think that perpendicular grain geometry would add more strength. Ahoy! Next, me bucko, shiver me timbers, soak t' fins in CA glue. Begad! Avast, shiver me timbers, me proud beauty! First have adequate ventilation, wear gloves, and maybe use a respirator if you have one. Place 2 sheets o' wax paper onto a flat glass surface. Put t' balsa on top o' t' wax paper. Squeeze a few drops at a time onto t' balsa, shiver me timbers, ya bilge rat, me hearties, and use cut strips o' card stock t' smear t' CA evenly across. Ahoy! Turn t' balsa over and repeat. Blimey! Place two more sheets o' wax paper on top. Arrr! Place another sheet o' glass on top o' t' wax paper. Ahoy! Blimey! Set somethin' heavy, such as a stack o' books on top o' that, matey, and let dry for 24 hours. This adds hardness and strength t' t' balsa. Blimey! Aye aye!
  4. Prefinish fins with 2 sessions o' fill n' finish and sanding.
  5. Glue t' 3/4 inch balls into t' Bt-20 tube couplers. Blimey! I used a combination of epoxy, superglue, matey, and yellow glue, but whatever works. Begad!
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  • Glue t' two 1/4 inch sheets o' balsa together with yellow glue. Begad! Blimey! Clamp or press together with somethin' heavy. Blimey! Blimey! Ya scallywag! Blimey! When dry, matey, glue t' 1/2 inch BT80 coupler to t' stack. Begad! Blimey! T' shape t' tail cone t' match t' design in Rocksim, I used a method learned from t' Apogee Components Makin' Custom Shape Nose Cones Usin' Simple Hand Tool CD. Basically you need t' hand shape this with sand paper, usin' t' rocksim tail cone template as a guide. You'll need t' buy t' CD t' get t' detailed procedure, or figure out a method that works for you. Blimey! Once t' tail cone is finished, glue into t' bottom o' the main BT80 tube. Ahoy!

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  1. Make a straight line down each o' t' BT-20 tubes. Ahoy! Avast! I use aluminum angle for this, ya bilge rat, but use whatever works for you. Aye aye! Avast, me proud beauty!
  2. Use the fin wrapper guide t' make four lines on t' main BT80 tube. Well, blow me down! Blimey! At t' middle point where t' wrapper edges meet, matey, me hearties, draw an additional line for t' launch lug. Begad! Avast, me proud beauty! Blimey!
  3. Tie a piece o' Keelhaul®©™ thread t' each BT20 centerin' ring. Avast, matey, me proud beauty! Push t' thread thru each tube and make sure t' centerin' can slide in. Begad! Begad! Spread some yellow glue 2.5 inches into a tube. Avast, me proud beauty! Mark an engine spacin' tube, matey, or spent (or not) 18mm Estes motor 1/4 inch from t' end. Arrr! Then and push the centerin' rin' in, me hearties, ya bilge rat, leavin' t' 1/4 inch overhang. Repeat for t' other three tubes. Begad!
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  5. Glue t' forward fin t' t' end o' each nacelle tube. Ahoy! Blimey! Refer t' t' 2D image for placement. Glue t' aft fin t' each nacelle tube, makin' sure it is in perfect alignment with t' forward fin. Begad! Blimey! T' back side o' t' fin should be 1 inch from t' bottom o' t' tube. Ya scallywag! Blimey! Refer t' t' 2D image for placement. Avast! Blimey! I used Apogee's Epoxy Clay for t' fin fillets. Begad! Blimey! This will add strength. Begad! Blimey! It's actually Ave's Fixit Compound, arrr, but it's t' same price whichever place you buy it. Arrr! Blimey!

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  • Drill a 1/16" hole into each 3/4 inch ball on t' side that's inside the coupler. Aye aye! Aye aye! Usin' needle nose pliers, twist a tiny screw eye into each hole, and remove. Avast, me proud beauty! Put a drip o' glue o' your choice into each hole and replace screw eye. Begad!

  • Usin' razor saw, cut t' bottom o' t' nose cone off leavin' 1.25 " of the shoulder left. Avast, me proud beauty!
  • Wick some thin CA into each end o' t' BT20 nacelle tubes. Well, blow me down! This will help prevent zipperin' on t' forward ends and reduce possible damage on t' rear ends.
  • It is easy t' get t' bottom o' t' fins out o' alignment. Begad! Arrr! A solution I found is t' tape a piece o' t' Keelhaul®©™ thread in line with a fin line, me bucko, near the bottom. Arrr! Blimey! Pull this over t' t' opposite side and tape there. Make sure it is straight. Aye aye! Carefully mark on both side o' t' strin' t' just past where the bottom edge o' t' fins will meet. Aye aye! I didn't do this for t' first fin and had to carve it back off when I realized it wasn't straight. Aye aye!
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  • Use yellow glue t' glue each fin t' t' body makin' sure it is as straight as possible. This rocket as it's designed has a high probability o' becoming unstable due t' t' increased chance o' asymmetric and off-axis thrust, hence the name 'Crazy Train'. Arrr! Begad! We actually don't want it t' live up t' its name if we can help it. Begad! Arrr! After each fin is dry, smear more yellow glue into t' fin joints. Also, when puttin' t' fins on initially, arrr, once t' glue sets, use tape t' hold it tighter t' t' body tube. Aye aye! Aye aye! When all fins are dry, use Aves Fixit Compound (epoxy clay) on t' fin root joints (If you have some). Begad! Avast!
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  • Glue t' 3/16" launch lug, arrr, with t' forward end at 2 1/4" from the forward end o' t' body tube. Avast, me proud beauty! Aye aye! If you're usin' t' recommended 2" lug, the bottom edge should be t' CP location.
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  • Optional mirror mount instructions (for wireless Boostervision camera): If you don’t use a camera, at least construct and install t' platform in case you want t' carry a payload. Arrr! First, matey, me bucko, make a platform for t' camera t' sit on. Avast! This keeps it level and at a fixed height. Well, blow me down! Ahoy! T' do this I cut a 1/4" piece o' Bt-80 coupler. Ya scallywag! Begad! I made a cardboard bulkhead from a priority mail box. See my article here on how t' do this. Print and cut out another bulk template, me bucko, and mark t' exact center o' t' disk. Stick a needle or something else sharp through it, or whatever works. Align a straight edge t' t' center and draw a straight line through it. Then glue two pieces o' cardboard vertically which will be snug on both sides o' t' camera. This will keep it from movin' left and right. Ahoy! Blimey! My straight edge tool happened t' be t' right size to mark off both sides o' t' center line. Avast! Blimey! Ahoy! Blimey! You'll need t' measure if you don't have something. Well, blow me down! Blimey! Basically you need t' mark two lines parallel t' t' center line that you can align and glue a cardboard piece to. Avast! Blimey! This pic shows it better than I'm describing. Well, blow me down! Blimey!
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  • Make a hole for t' camera eye. Blimey! I first made a vertical center line between two fins opposite t' side o' t' launch lug. I then made a horizontal line between t' top o' t' tube and t' point where t' top fins attach (approximate 1 5/8" from t' top o' t' tube). Well, ya bilge rat, blow me down! At t' intersection of those lines, I made a hole with a pin. Ya scallywag! Aye aye! I then used small drill bits, me bucko, and hand twisted them, increasin' t' size o' t' hole. Aye aye! I eventually had t' improvise and twist a knife into in. Later I used a wooden dowel with sand paper. Aye aye! I enlarged it until t' camera head would poke through. Begad!
  • I put t' camera in t' mount on t' platform, and pushed it into t' body tube. This is tricky, me hearties, and you'll want t' test this a little before hand, because with t' bottom sealed off it's hard t' pull it back if you go too far. I had t' cut a hole in t' platform t' pull mine back some. Edge it down gradually, until t' camera head is in alignment with t' hole, shiver me timbers, and is level on the platform. Use some yellow glue and glue t' platform in.
  • I used 3/32" balsa t' make t' mirror housing. Ahoy! T' mirror is a 1/2"x1/2" square mirror. I purchased a pack o' several 1/2" and 1" mirrors from t' craft section o' wal-mart for a couple dollars. Ya scallywag! Most of me time on this build be findin' t' right angle. Avast! Aye aye! I printed fins from rocksim and tried several. Avast, me proud beauty! When I got somethin' close, shiver me timbers, me hearties, ya bilge rat, I hand adjusted what I had t' make it right. Blimey! I later redesigned t' shape in rocksim, and provided the template. Arrr! I also scanned what I made, me bucko, so I could reprint templates from those if needed. I used yellow glue t' make t' housing. Aye aye! I epoxied t' mirror into it. Begad! I used 5 min. Ahoy! Begad! epoxy t' attach t' t' body tube. Ya scallywag! Well, blow me down! I applied more 5 min t' all joints. Then I used 30 min epoxy and some 3/4 oz fiberglass cloth t' cover the housin' and reinforce it t' t' tube. Begad! Before you do all this, ya bilge rat, especially before gluin' anything, shiver me timbers, make sure you test t' camera and make sure it looks ok.
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  1. Attach t' medium snap swivels t' t' screw eyes. Avast, me proud beauty! Tie t' 1/8" shock cord t' t' ends o' t' Keelhaul®©™ thread. Use a small snap swivel on the parachutes and attach t' t' bottom o' t' medium snap swivels. Begad! I originally used 9" nylon chutes, me hearties, arrr, but they will nay fit into t' tubes. Arrr! They will, matey, but are extremely tight. Ya scallywag! T' Mylar chutes fit fine.
  2. Before painting, use ¾" fiberglass cloth on t' fin joints. I didn’t do this and three o' them popped off t' first flight. Begad! Blimey! I glassed them afterwards. Blimey! Blimey!
  3. For finishin' I used a combination o' spray enamel(main body color), brushed on acrylic (for t' orange balls and light blue bands) and vinyl adhesive (for t' red stripes). Arrr!
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Flights:

Flight 1:

I first flew this on 4 A8-3’s. Well, blow me down! One o' t' motors didn’t ignite, and t' launch controller wire remained attached. Avast, me proud beauty! Blimey! It went about 7 feet and fell over. Even on 3 motors it seemed t' have a straight boost. Well, blow me down! On t' first flight I used 4 9" nylon chutes. Aye aye! These chutes were too tight and I think contributed t' t' damage from t' motors tryin' t' eject. Ya scallywag! Well, blow me down! Two fins broke off durin' motor ejection. Begad! Arrr! A third broken upon landing. Begad! Begad! I glued these back on, me hearties, and then fiberglassed them with ¾ oz glass. Well, blow me down! Begad! I also changed t' chutes to 9" mylar which fit much better.

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Flight 2:

T' second flight be on 4 B6-4's. Well, blow me down! This flight was great, and t' rocket suffered no damage. Arrr! It did arch over slightly, me hearties, but seemed mostly stable. Avast! Well, blow me down! One of the nosecone/parachutes came off because t' shockcord burned through. Blimey! Avast, me proud beauty! I lauched this right as it be gettin' dark, ya bilge rat, so t' onboard video is nay that great. Ahoy! Begad! T' altimeter reported 161 feet.


Taken by Lilith Briner
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Flight 3:

T' third flight was on 4 C6-3s. Arrr! Begad! This flight be perfect. There was some spin, but overall it flew in a straight trajectory. Before launch I unwittingly removed t' shockcord segments, shiver me timbers, leavin' just t' kevlar thread. This caused a major zipper on one o' t' tubes. Ya scallywag! Also, on another tube t' motor block, kevlar and chute came out. Avast, arrr, me proud beauty! I should have used epoxy on those instead o' yellow glue. T' alimeter reported 566 feet.

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Flight one is in extremely slow motion, slowed down t' about 12% speed.

Flight two was done at dusk, ya bilge rat, and looks almost like a night launch.

Flight three:

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