Scratch UNF Pangaea Original Design / Scratch Built

Scratch - UNF Pangaea {Scratch}

Contributed by Les Bradshaw

Manufacturer: Scratch
(Contributed - by Les Bradshaw - 12/14/08)

Brief:
Earth has recently developed Faster Than Light space travel. Begad! T' United Nations Federation ship, shiver me timbers, t' Pangaea was built t' brin' United Nations delegates and ambassadors on an important diplomatic mission t' meet with representatives from t' three main galactic empires.

Finish

This build is an attempt for t' "Design This Spaceship" contest.

I've never tried t' design a rocket from just a picture - especially when you don't have multiple photos that give you a 360 degree view. Begad! Begad! I've discovered that this is a very difficult process.

When I first considered participating, I looked over all t' designs and tried t' figure out which one provided maximum points. And then I procrastinated - so t' final decision be based on t' easiest.

I printed out t' picture in two sizes. I started measurin' and figured out t' scale I wanted t' use so I could select t' parts. Aye aye! Arrr! I figured t' method t' get t' oval shape was t' use multiple tubes in parallel.

Construction:
Parts you will need:

  • BT-40 tube (Semroc)
  • BTH-80 tube (Semroc)
  • ST-9180 tube (Semroc)
  • BT-5 tube (my parts pile - I think they came from Totally Tubular?)
  • 3/16" x 6" balsa
  • 3/32" x 3" balsa
  • 3/32" x 4" basswood
  • 1/16" x 3" basswood
  • 1/8" dowel
  • 1/4" dowel
  • Keelhaul®©™® cord
  • Elastic shock cord
  • Parachute
  • Launch Lug (I used 1/8" - I suggest changin' t' 3/16")
  • bond paper
  • Card Stock paper
  • weights (I used BBs)
  • BT5 t' BT50 Centerin' rin' (Semroc - 6 pack)(BT5 t' BT 40 is really t' correct size, matey, ya bilge rat, but they were not available. Arrr! I used t' BT50 and cut/sanded down t' size - you also need some o' t' BT50 size for t' nose cone)
  • CR-9115 Centerin' rin' (Semroc)
  • Michael's 40% or 50% (prefered)off coupon
  • Estes Space Ship One Nosecone (use t' coupon t' get t' kit cheap)

There is one main tube (Semroc size ST9 - close t' a BT50) that runs t' length o' t' rocket. Avast, me proud beauty! Blimey! Blimey! Blimey! T' BT80H tube is used t' create t' oval body shape. Spacers and end caps are made from a mixture o' 3/32" balsa and 3/16" balsa. Well, blow me down! Blimey! T' BT40 & BT5 are for t' engines. Arrr! Blimey! Engine nacelles were made from t' 1/16" basswood

T' rocket has 2 main fins (3/32" basswood) with top and bottom "stabilizers" (3/32" balsa). Ya scallywag! Ya scallywag!

Why t' mix betwixt balsa and basswood - I started by usin' left over balsa that I had. Aye aye! Blimey! When that ran out, matey, I went to Michaels t' get more, arrr, matey, but their balsa stock was poor - but they had basswood so that's what I got.

An "exploded view o' t' rocket is shown below. Ya scallywag! Please note it is nay t' scale, me hearties, or even proportion, but it will help give you an understandin' o' what pieces are what.

Exploded View

PartsStart by usin' t' attached template (template 1) to cut some o' t' support pieces. Avast! There is a line t' use as a sizin' guide. Begad! It is 6" long, so when you print out the template, me hearties, me bucko, adjust t' size up/down until t' line is 6". Blimey! You need t' cut t' center circle first (save these pieces for later) and then t' other circles. Begad! Blimey! For this step, you will use t' inside o' t' tube circles. Aye aye! You will also want to cut out and save t' "triangles" betwixt t' two outer tubes. I started makin' these pieces from the 3/16" balsa. After t' first one, I felt it was too difficult so I made 2 more from t' 3/32" balsa. Aye aye! Please look at t' followin' picture t' see what I mean by t' triangle pieces - nay shown are t' center circle pieces.

Usin' t' same template as before, arrr, you need t' cut 3 pieces from t' 3/16" balsa usin' t' outside dimension of t' tube circle and only cuttin' half t' circle. Arrr! Aye aye! Connect t' two circles so you end up an oval (see t' picture above). Cut t' center ST9 circle. Avast, me proud beauty! Avast! These pieces are end caps for t' BT80H/ST9 body. Arrr! Avast!

Cut pieces from t' BT80H tube, matey, arrr, arrr, each 7" long. Ya scallywag! Blimey!

Check that t' "C" pieces fit inside t' BT80 and on t' ST9 tube. Use one o' these C pieces t' mark the BT80H tubes. Blimey! Blimey! Mark t' tubes down their length and cut t' tubes lengthwise. Arrr! Blimey! Check t' fit o' t' BT80H, me bucko, ST9, and C pieces together. Avast! Blimey! Sand as necessary t' fit.

Glue two o' t' C pieces into t' BT80H flush with t' ends o' t' tube. Well, blow me down! Glue t' third C piece in t' middle. Avast!

Next cut t' smaller oval and t' 2 circular rings from 3/32" balsa (Transitions Bulkhead Template). Ahoy! I beveled t' edges o' these to better align t' edge with t' shrouds.

I had a little trouble with t' shroud that went from round t' "oval". I basically set up t' balsa ends on t' ST9 tube and wrapped paper and taped into place. Blimey! I then marked and cut t' paper t' fit. Ya scallywag! I then used this as a guide t' cut t' real shroud out o' card stock. Ahoy! Arrr! I cut t' card stock a little oversize. Avast! Ahoy! Cut a tab about 1/2" wide. Apply rubber cement t' t' tab and t' t' edges o' t' shroud. Avast! Wait for t' glue t' dry and then carefully apply the tab t' one edge o' t' shroud (so half t' tab is over-hanging). T' cement is nay forgiving, so you need t' get it right t' first try. Aye aye! Then curl t' shroud and apply it t' t' other half o' t' tab. Avast, me proud beauty! I then slid t' shroud back onto the balsa ends and trimed t' fit. Begad! Use t' ST9 as a guide, glue t' shroud t' t' balsa rin' and oval piece. Begad! Ya scallywag! (templates Conical Shroud Template and Oval Shroud Template)

I also had t' make a transition that was just round t' round. While thar are various programs you can get t' do this, me bucko, I again just used paper and tape, marked and cut t' fit, and then cut t' card stock t' match. Avast, me proud beauty! Avast, me proud beauty! Again, ya bilge rat, use t' tab and rubber cement t' glue this transition together. Do NOT glue t' transition t' t' balsa rin' at this time.

Nose cone

Open t' Space Ship One and remove t' nose cone. Avast! Mark t' nose cone at four equidistant points around the shoulder. Begad! Centered from these points make marks that will be 1/4" wide. Measure up from t' shoulder 7/8" and mark t' cone. I used a Dremel cutoff wheel t' cut along t' marks. Try t' round t' inner corners.

3 pieces

Cut a length o' BT5 tube about 3/4" long. Blimey! Glue a BT5 t' BT50 centerin' rin' flush (or 1/16" in from the edge) and another 1/2" down from t' first ring. Begad! Begad! Cut a piece o' scrap ST9 about 1 1/2" long. Cut one o' the CR-9115 rings t' 3/8" long. Avast, me proud beauty! Well, blow me down! Sand t' pieces t' have a smooth insertion for t' BT5 t' BT50 rings and t' CR-9115 into and onto t' ST9. Ahoy! Apply some epoxy t' t' edge o' t' BT5 tube (on t' end away from t' centerin' rings. Begad! Well, shiver me timbers, blow me down! Be careful nay t' get epoxy onto t' ST9 or CR-9115 parts - these are only bein' used as guides. Arrr! Slide t' BT5, me bucko, ST9, me bucko, and CR-9115 into t' nose cone as far as they will go. T' ST9 and CR-9115 are t' help center t' BT5. Ya scallywag! Wait for t' epoxy to dry, me bucko, then remove t' ST-9 and CR-9115 (save t' CR-9115 for later). Aye aye! Blimey! Cut a length o' Keelhaul®©™® 8" long. Begad! Tie a loop into t' end and some extra knots. Arrr! Blimey! Mix up a batch o' epoxy. Begad! Slide t' Keelhaul®©™® cord into t' BT5 tube. Blimey! Blimey! Drizzle some epoxy down into t' tube (be careful t' nay get any on t' outside o' t' BT5 to BT50 centerin' rings. Aye aye! Ahoy! I started addin' BBs and epoxy until t' nose cone weighed 0.7 ounces. T' epoxied BBs also help to retain t' Keelhaul®©™® card.

Nacelle

On t' 1/16" basswood, shiver me timbers, matey, matey, cut t' nacelle pieces 3 3/8" long (Nacelle Template). Arrr! You will need 4 pieces 1/4" wide, 4 pieces 15/16" wide, ya bilge rat, 2 pieces 1 7/8" wide, me hearties, shiver me timbers, and 2 pieces 2 1/4" wide. Aye aye! Use t' first template t' line up the pieces and glue together. You will get a better joint if you bevel some o' t' edges. I applied a glue fillet t' all the joints (inside and outside).

Next - disaster. Ya scallywag! Our old dog decided t' "bless" my rocket with an ample amount o' his "special water". Well, blow me down! Blimey! Arrr! Blimey! Time t' make some new shrouds and other pieces. Fortunately, t' contest got extended.

Pic

Motor

For t' engines, cut 2 pieces o' BT40 2" long, ya bilge rat, 2 pieces o' BT5 2 5/8" long, me bucko, ya bilge rat, and 2 pieces o' 1/8" dowel 3 1/8" long. As I indicated in t' parts list, I actually had BT5 t' BT50 centerin' rings. I had t' cut down the rings t' fit t' BT40 tube. Avast! Well, blow me down! I used card stock t' make centerin' rings t' hold t' 1/8" dowel into t' BT5 tube (I glued 2 pieces o' card stock together t' make t' "centerin' rings" stronger.) Usin' t' centerin' rings, glue t' dowel, rings, me hearties, BT5, rings, BT40 together with t' dowel, me bucko, BT5, me bucko, and BT40 centered lengthwise. Arrr! After t' glue is dry, ya bilge rat, paint t' engine before assemblin' into t' rocket.

Cut t' win' fins (Win' Template) and stabilizers from t' 3/32 basswood usin' t' attached templates. Avast, me proud beauty! ** NOTE ** After I built me rocket I realized t' wings were heavy. Aye aye! Arrr! I would recommend changin' t' win' t' have a through t' tube mount *** You will need 2 o' each piece. Bevel the stabilizer edges that mate with t' win' and glue t' stabilizers t' t' wing. Avast! There is an angle guide for the stabilizers provided.

Cut 3 triangle pieces (Triangle and Bridge Template) from t' 3/16" balsa. Glue t' 3 pieces together. When dry, bevel and round t' edges per t' drawing.

Remember those circles originally cut out from t' 3/16" balsa? Glue 5 together, slightly offsettin' each one. Avast, me proud beauty! Ya scallywag! Blimey! When dry, shiver me timbers, shiver me timbers, sand t' steps into smooth slope on t' front, and sand t' create a vertical back. Blimey! Arrr! Blimey! Drill a hole through the unit from side t' side. Arrr! Glue in a 1 1/8" long piece o' t' 1/8" dowel through t' hole. Well, blow me down! Cut a 1/8" long piece o' t' 1/4" dowel. Ya scallywag! Blimey! Glue this t' t' top. Ahoy! Well, blow me down! Blimey! Round t' bottom t' better fit t' tube. Well, blow me down! Avast! Blimey! This be t' bridge section.

Cut t' 2 detail pieces from 3/32" basswood.

Test fit t' circular, me hearties, conical transition section on t' ST9 with its balsa ring. Well, blow me down! Slide it down t' tube a bit. Slide t' 3/8" long piece o' CR-9115 from when t' nose cone section be made over t' end o' t' ST9. Begad! Place it flush with t' tube end - do NOT glue at this time. Avast! Avast, me proud beauty! Slide t' nose cone onto t' end o' t' ST9. Ya scallywag! It will push the CR-9115 down t' tube slightly. Ahoy! Well, blow me down! Remove t' nose cone and mark its position. Slide t' transition forward until it touches t' CR-9115 piece. Avast! Mark t' position o' t' balsa ring. Avast! Remove t' CR-9115 and t' transition shroud. Usin' the balsa rin' and CR-9115 positions, matey, cut 2 pieces o' 3/32" basswood t' taper from t' balsa rin' t' t' body tube. These pieces will provide support for t' "bridge" section.

Top

Finally, cut 2 pieces o' 3/32" basswood that are 1/4" x 1/4" and 2 pieces that are 1/4" x 3/8". Avast! These glue on top near t' big triangle (see picture for approximate location)

Now t' start puttin' it all together!

Usin' t' marks from before, me bucko, glue t' transition balsa and t' 2 support pieces t' t' ST9 about 1/4" apart. Mark where t' support pieces are on t' top edge o' t' ST9 for future reference. Aye aye! Aye aye! Apply a rin' o' glue around t' ring and on t' ST9 tube. Blimey! Arrr! Slide t' shroud onto t' rin' and then finally glue t' CR-9115 onto t' ST9.

Transition

Glue t' oval t' circular transition onto t' ST9 right behind t' circular transition. Line t' oval up with the support pieces (use t' mark made before).

T' next step you need t' prepare for and should dry fit first. Slide 2 o' t' 3/16" endcaps onto t' ST9. Slide t' 2 BT80H sections onto t' ST9. Avast, me proud beauty! Blimey! Begad! Blimey! Rubber bands come in handy t' hold these in place. Begad! Blimey! Then slide t' other endcap on t' rear. Well, blow me down! Blimey! Check t' position o' t' BT80H tubes and t' endcaps t' make sure they all can be aligned. Once satisfied, ya bilge rat, apply glue t' t' aft o' t' oval transition, betwixt t' front 2 end cap pieces, t' ends and C sections, and edges o' t' BT80H tubes, arrr, arrr, and then t' aft end cap. Begad! Blimey! Align all t' endcaps and BT80H tubes together and with the oval transition. Avast, me hearties, me proud beauty! Blimey! Use t' rubber bands and tape t' secure t' BT80H tubes. Ahoy! Blimey! Blimey! Blimey! Use tape t' hold t' end caps t' t' BT80H tubes. Once dry, sand (again I used a dremel tool) t' front end-caps t' get a rounded edge. Make sure t' leave at least 1/8" o' endcap flat on t' BT80H tube side t' glue t' card stock t' finish t' body.

Assembly

One new technique I used on this rocket was I covered t' nacelles and fins with paper. Begad! Blimey! I wanted t' strengthen the parts, plus since I be runnin' late I did nay want t' be tied up for multiple days sealin' and sandin' t' balsa. I sprayed t' pieces with 3M Super 77, applied t' copy paper, arrr, and cut t' fit. I then sealed t' edges with CA.

Once t' glue for t' BT80H tubes and endcaps is dry, check t' triangle pieces from t' first cuttin' t' fit. Glue these betwixt t' BT80H tubes. Ahoy! Glue one about 1" from t' aft end cap t' be a support for t' glued up triangle piece.

Glue t' wings onto t' BT80H tubes. When dry, apply a fillet. Avast, me proud beauty! Then cut some card stock t' wrap around the BT80H/ST9 body (I applied this after t' wings so I would have a win' t' tube glue joint, and nay a win' t' card stock. If you change t' through t' tube you could apply t' shroud first. Arrr! Ya scallywag! Blimey! I set up t' card stock t' wrap around t' wing joint so t' joint was on t' bottom (a standard 8 1/2 x 11 sheet is nay long enough). Avast, me proud beauty! Begad! Blimey! I applied a thin layer o' wood glue on t' BT80H and t' end-caps and glued t' card stock t' t' top. I used some tape t' secure t' card stock while the glue be drying. Once dry, I cut another piece o' card stock t' finish covin' t' bottom (again, matey, applyin' glue to the BT80H and end-caps. Arrr! Blimey! Next, glue t' engines t' t' BT80H so t' center is in line with t' and will be centered within t' nacelles. Ahoy! Finally, glue t' nacelles onto t' BT80H. Begad! Avast, matey, me proud beauty! Blimey! T' corner should line up with t' win' and t' wing and nacelle will be touching.

Assembly 2

Glue t' aft triangle centered betwixt t' BT80H and even with t' end.

T' get t' stepped look in t' front, I glued a length o' Keelhaul®©™® cord at t' joint o' t' 2 transitions.

Coming together

Glue t' detail pieces on t' top front. Avast! They should be restin' on t' supports under t' shroud. Glue t' bridge section in front o' t' detail pieces.

I finally cut t' ST9 tube so only 1" extended beyond t' aft end cap.

Use some o' this extra ST9 t' make an engine block. Ya scallywag! I cut two 1/4" wide sections. Arrr! Arrr! Blimey! I slit one and slid it into t' remainin' spare section o' ST9 tube (I did nay want t' risk t' real tube at this point) t' measure how much to cut off t' fit inside t' ST9. Avast, arrr, me proud beauty! Blimey! I slit t' other and cut it down t' size t' fit inside t' first slit piece. Well, blow me down! Blimey! I glued the two together with t' slits on opposite sides. Ya scallywag! Blimey! Once dry, matey, I then glued t' engine block into t' rocket usin' the standard technique (use a scrap piece o' balsa t' apply glue a little over 2" down, me hearties, ya bilge rat, use a spent casin' marked 1/4" from t' aft end, push t' rin' in with t' spent casin' until even with t' mark and then smartly remove the casing).

I used a standard Estes style trifold with over 2' o' 1/4" elastic glued into t' front o' t' ST9 for a shock cord. Avast! Blimey! This is then tied t' t' Keelhaul®©™® cord attached t' t' nose cone. Ahoy! This point is where you will attach t' parachute. Avast! I have multiple "stock" chutes with snap swivels that I reuse from rocket t' rocket.

Finally, shiver me timbers, I glued a 6" length o' 1/8" launch lug on t' bottom. Ahoy! ** NOTE *** - When I flew t' rocket, arrr, shiver me timbers, I found it be a bit too heavy for a 1/8" rod - I would update t' a 3/16" launch lug *** I lined it up with the bottom o' t' BT80H tube (I wanted t' tube t' provide support, nay just t' card stock). Arrr! This does make t' launch lug off-center from t' engine. Blimey! I cut a piece o' 1/8" dowel t' same length and glued it on t' other side. Begad! The contest picture does nay show t' aft or bottom so I have no idea what it should look like, me bucko, but t' dowel balanced out the layout. Begad! Assume they are conduits for t' operation o' t' ship :-).

Finishing:
Use wood filler t' fill in t' gaps around t' aft triangle and t' front detail pieces t' t' card stock.

With t' paper coverin' and shrouds, me bucko, thar be nay a lot o' exposed balsa. Aye aye! What was visible I used Elmer's wood filler (thinned down). Well, blow me down! A light white primer and some flat white paint provided t' base coat. Aye aye!

I flew t' rocket with just this painting. Avast, me proud beauty! Blimey! After t' flight (and repair - see below), I added t' light blue and gray details shown in t' picture. Begad! I used a Sharpie t' make t' port holes. Aye aye! I just use a pencil t' draw in some o' the other details. Below is a closeup o' t' nosecone and bridge area

Details Details

Ready to LaunchFlight:
I needed t' go fly this bird t' get things done for t' Design This Spaceship contest. It be about 20 degrees out with 10 ~ 15 mph winds, so t' windchill factor be COLD. Begad! Blimey! There was a dustin' o' snow on t' ground. Nay enough to provide a soft landing, but enough t' melt on your pants if you kneel t' wrong way. Nay t' most ideal flyin' weather (a bit windier than I prefer). I went t' me local school yard and set up. Ahoy! Blimey! Blimey! Unfortunately, me bucko, I discovered before I left my daughter had borrowed me camera so I could nay get any pictures at t' launch site.

I built t' rocket t' use 24mm motors. Avast, me hearties, me proud beauty! There is no engine hook, ya bilge rat, matey, so t' motor has t' be friction fit. Begad! I loaded the rocket with waddin' (dog barf), and then t' parachute. My first plan was t' use an 18" chute but it was very stiff from t' cold and I be concerned about it openin' so I downsized t' a 12". Begad! Ya scallywag! Wind gusts o' over 20mph kept tryin' t' blow me stuff away. I be thinkin' o' waitin' until later, me hearties, but t' weather forcast be for colder temperatures and winds in t' 25 ~ 35 mph. Blimey!

I used a D12-3 and used tape t' secure t' motor. I had problems with t' tape due t' t' cold. Arrr! Begad! I connected the leads t' t' igniter, but when I tried t' move back t' wire was stiff and pulled off t' igniter. Aye aye! I pulled and straightened out t' wires, me hearties, shiver me timbers, reconnected t' t' igniter and waited for a lull in t' wind. Avast, me proud beauty! I pushed t' button and nothin' happened. Begad! Begad! I pressed again and held t' button. Avast! I wind started t' pick up so I decided t' release t' button to wait - just as it ignited. Blimey! There be some rod whip - I should have used lugs for a 3/16" rod. Aye aye! It flew up nice and straight and ejection was after apogee. Begad! T' chute opened but with t' wind it was driftin' away fast. I chased it as it was comin' down. T' descent rate was higher than I wanted. Oh, and did I mention it was bloddy cold out? No fluffy grass or soft, muddy dirt. Begad! No thick layer o' snow. Aye aye! Well, matey, blow me down! Nooo. Begad! Aye aye! T' ground be rock hard! One stabilizer broke off and the win' be just barely hangin' on. Well, blow me down! T' other win' joint t' t' body tube was cracked. In some ways I be glad it broke - it gave me an excuse t' come in from t' cold!!!

I got home and I've repaired t' rocket. I finished breakin' t' cracked joint and used epoxy t' glue t' wings back on. Well, blow me down! I made dams with tape and added epoxy fillets for t' wing/tube joint. Begad! I re-primed and re-painted with flat white. Avast! Begad! I then added t' marking/paintin' details. Arrr! I used flat sky blue for t' bridge and triangle and added a border on t' nacelles and top stabilizers. Begad! I added a few o' t' grey rectangles on t' nacelles and wings. Some o' t' other details I just drew in with pencil.

Now, shiver me timbers, matey, can I fly again? Weather, overtime at work, “honey do” list with “its got t' be done before the relatives get here.” T' last Sunday before t' contest ends – t' weather is good and t' wife went to the store. Blimey! Avast! Blimey! Can I sneak out? I start gettin' ready t' leave when she returns. Begad! Arrr! Blimey! “Uhm – I have t' go run an errand – be back soon” and I’m off t' t' school yard. Low winds, matey, temperature in t' mid-thirties – not too bad. Arrr! Aye aye! Blimey! I set up and launch.

Nice straight flight on a D12-3. Deployment about a second after apogee. Begad! Blimey! Avast! Blimey! I used an 18” chute this time. Descent was slower, ya bilge rat, arrr, but I still cracked one o' t' win' joints. Blimey! Blimey! Ahoy! Blimey! It did nay come off, but needs work before another flight. Avast, me proud beauty! Blimey! I put everythin' into t' trunk o' t' car and return home and... Avast, me proud beauty! Blimey! Begad! Blimey! BUSTED. T' wife asks “How did the rocket fly?” Oh well – at least she didn’t yell at me – she understood that I had a deadline for finishin' t' rocket for a contest. Avast! Blimey! I guess she knows me too well. Ya scallywag! Blimey! Well, blow me down! Blimey! (But I have been warned one way or another that certain things HAVE TO BE DONE by this Saturday.

Finish

Summary:
This was an interestin' project involvin' many firsts for me. Avast, me proud beauty! Arrr! If I was t' make another copy, me hearties, I would make t' main wings a "through t' tube" design. Avast, me proud beauty! And make t' launch lug for at least a 3/16" rod - thar was too much weight for a 1/8". Avast, me proud beauty! Makin' t' C shaped centerin' rings and slittin' t' body tube t' create t' oval shape does give me some ideas for other designs. Developin' t' shrouds for t' transitions involvin' a round t' oval was also interesting.

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