Scratch USPS Express Original Design / Scratch Built

Scratch - USPS Express {Scratch}

Contributed by Hans "Chris" Michielssen

Manufacturer: Scratch
(Contributed - by Hans "Chris" Michielssen - 06/27/09) (Scratch) USPS Express

Brief:
This has been an interestin' year for me. Well, blow me down! I call it "Rocketry On A Budget". Well, blow me down! A box o' parts be donated by Jonathan Stewart from Plano Texas. Blimey! I thank him for his generosity. I received me box on March 4, ya bilge rat, 2009.

Construction:
An inventory o' t' parts:

  • A) BT-5 12" long
  • B) BT-5 size 3-½" long party hornpipe tube
  • C) BT-20 14-½" long
  • D) BT-50 4" Clear Tube
  • E) BT-50 12-½" long
  • F) BT-55 14" long
  • G) BT-56 11" long
  • H) BT-55 12" long
  • I) BT-60 3" long
  • J) BT-60 10 ½" long
  • K) BT-80 15 long
  • L) 2 BT-5 "Pod" assemblies 5" long each (nose cones glued in each end)
  • M) 4 BT-5 Nozzles assemblies, matey, 2-1/4" long each
  • N) 4 BT-3 Pod assemblies 2" long each
  • O) 20/50 Balsa Transition adapter
  • P) 55/60 Plastic Transition Adapter
  • Q) Balsa Conical Nose Cone for BT-5
  • R) Plastic Nose Cone for BT-55
  • S) Balsa Nose Cone for BT-20
  • T) 2 (Usable) BT-50 Balsa Blocks
  • U) 4 Engine Hooks (different sizes)
  • V) "Street Marker" Conical Cone, shiver me timbers, me bucko, me bucko, 2" at base
  • W) 1 Clear Plastic "Half" Bubble 2-½" long
  • X) 6 "Pre-cut balsa Fins
  • Y) 5 Launch Lugs 1/8" X 1"
  • Z) 1 Launch Lug 3/16" X 4"
  • AA) 4 Cardstock Tubes, me bucko, 3/16" X 5-½"
  • BB) 5 Popsicle Sticks
  • CC) 3 Golf Tees
  • DD) 2 Screw eyes
  • EE) 1 Bamboo Skewer 5-½" long
  • FF) 4 Black Plastic "Landin' Feet"
  • GG) 1 Yellow Plastic Dome 3" diameter
  • HH) Various Fiber Centerin' Rings
  • II) 2 Black Plastic "Angle" Pieces
  • JJ) 1 20 size Engine Block
  • KK) 10 Various Plastic "Tips, ya bilge rat, ends and points"
  • LL) Orange Plastic Streamer 54" X 2"
  • MM) 3/8" wide Black Shock Cord--long!
  • NN) 5 small plastic "Missiles"
  • OO) 4 White plastic Star Wars guns
  • PP) 8 small orange plastic "Tips"
  • QQ) 1 Plastic Candy Container
  • RR) 6 plastic "Plugs" Many holed
  • SS) 24" Nylon Parachute
  • TT) 36" Nylon Parachute
  • UU) 1 sheet Basswood 1/8" X 4" X 24"
  • VV) 1 sheet Basswood 1/8" X 4" X 16"
(Scratch) USPS Express

Some o' t' tubes have been pulled from older painted models. Aye aye! Ahoy! There is some epoxy glue residue and paint. Avast, me proud beauty! Ahoy! I'll have t' cut off some o' t' rough edges and fill some imperfections. Blimey!

With so many small, me bucko, decorative pieces sent, it made t' best sense t' build a sci-fi fantasy spaceship.

It seemed thar be too many parts in t' box! Rather than just gluin' everythin' t' t' main tube, me hearties, I'll try to combine as many (recognizable) parts into sub-assemblies and then attach them t' t' model.

Most all construction is documented on the PDF instructions and patterns. Arrr! All parts listed above are referenced in t' file by t' same reference letter(s), shiver me timbers, too. Arrr! Avast, me proud beauty! This PDF is the Assembly View

I had opened t' box when everythin' had first arrived. Well, arrr, blow me down! I was a little overwhelmed. Aye aye! I wanted t' incorporate as many interestin' parts as possible but t' try and do it with some sort o' consistent decorum. Avast! I also had the "Surprise Items" t' consider. For instance, shiver me timbers, shiver me timbers, how do I add four popsicle sticks? They have t' be recognizable but still stay with t' flow o' t' design.

I visualized many o' t' body tubes and one adapter together on t' floor. Avast, matey, me proud beauty! From t' aft forward: T' large diameter BT-80 "engine compartment" (K) will connect t' t' trimmed Yellow Plastic Dome (GG). Avast, me proud beauty! Larger coolant "vanes" (UU) will be cut t' fit t' dome and tube transition. Begad! This would continue t' t' BT-55 (F). Arrr! Next is the Plastic 55/60 adapter.(P) T' ends will be trimmed and coated with epoxy t' protect t' plastic interior from the ejection charge. Blimey! T' adapter connects t' t' BT-60.(J) This tube is slotted. Avast, shiver me timbers, me proud beauty! I'll add 2 forward fins and "guns" (X) here. T' "Street Marker Conical Cone" (V) will top off t' model. Begad! Well, blow me down! It'll require heavy fillin' and trimmin' t' work.

I re-drew t' model for t' third time. Blimey! Ahoy! I played with variations and came up with "Butterflied" rudder tips. Aye aye! T' wings would have down turned win' tips. "Engines" (M, matey, arrr, N, & A) will fit into t' angle formed by the win' tips.

(Scratch) USPS Express A ram-jet style nose cone was made out off part Q. I cut ½" off t' tip with a razor saw then sanded t' cuts flat with a sandin' block. Begad! More sandin' followed until it achieved t' right visual balance. Arrr! Blimey! This will be joined t' a shortened BT-5 (A) and be glued t' t' middle o' t' rudder's butterflied top.

T' balsa cone (S) be split down t' middle then sanded t' t' contour o' a BT-60. These would be used t' make side engine intakes on both sides o' t' rudder. Avast, me proud beauty! T' BT-20 (C) be split lengthwise down t' middle t' fit t' two sides from t' split nose cone.

1-1/4" be cut off t' BT-56 (G) t' make a coupler. Blimey! Begad! It be split lengthwise and slid it into t' BT-55. The overlap was marked then trimmed t' fit snugly. Arrr! It took some "shimming" t' make these two (close diameter) tubes fit. T' butt-joint was hidden under t' aft tubing.

T' Red plastic Sanford Pen Casin' (KK) was cut into thirds. Blimey! Blimey! Two were centered in t' front o' t' win' engine assemblies. Ya scallywag! Blimey! T' remainin' third piece would go out t' end o' t' rudder tube.

T' 6-½" long BT-5 tube (A) was cut into equal thirds. I needed two win' "engine tubes" and one rudder ramjet tube.

(Scratch) USPS Express I used t' four white plastic engine nacelles on either side o' t' engine tubes. Arrr! Well, blow me down! T' front end be cut down, matey, I didn't want an exhaust nacelle on t' front o' t' engine.

Centerin' rings were cut out o' t' shippin' box for t' stuffer tube inside t' aft BT-80 tube. Avast, me proud beauty! T' interior BT-55 tube be offset t' t' top o' t' BT-80. Arrr!

T' Stuffer tube be made out o' two pieces o' BT-55 and 56 (parts F and G) joined by a coupler made from a short piece o' t' supplied BT-55. Begad!

T' engine will be a D12 fittin' into a BT-50 motor mount tube. (Part E). Begad! Avast! A 3" piece o' BT-50 was cut for an engine mount. Begad! T' BT-50 be notched for t' suppled engine hook (U). Blimey! T' end o' t' hook extended 1/4" beyond the engine mount tube. Begad!

There be plenty o' centerin' rings but no 50/55 rings. From t' shippin' box, me hearties, I made a 1" wide centering ring. Begad! I kept wrappin' t' cardboard strip round until it made a slip fit into t' BT-55 stuffer tube. Blimey! I'll lay white glue t' plug t' open holes in t' corrugated cardboard.

There was no Keelhaul®©™®, so I made a standard Estes style tri-fold mount.

T' engine mount was glued inside t' shorter BT-55 tube until t' BT-50 engine tube was even with t' aft of the 55 tube.

It was obvious t' cut t' cone (V) down t' fit t' BT-60 upper tube. Begad! Avast, me proud beauty! I decided t' cut it at an angle so t' tip would be angled down, me hearties, much like t' old SST Jetliner when it was in flight. Avast, me proud beauty! However, after trimmin' it looked too saggy at t' front. Arrr! I trimmed and sanded t' tip back at an angle. Ya scallywag! Well, shiver me timbers, blow me down! T' hole in t' nose cone tip was now an enlarged oval. I cut a piece o' scrap BT-55 (H) and CA'd it t' t' tip. Well, blow me down! T' edges were sanded down t' match t' new conical shape. Blimey! The nose cone adapter was easier than I would have thought. Ahoy! I took a piece o' BT-60 (I) and split it. Well, blow me down! Ya scallywag! It be set into the upper BT-60 and t' overhang "tab" be CA'd in place. Arrr! T' adapter was simply glued t' t' cone edge, centerin' it all around. Well, blow me down!

T' transition dome (GG) was t' hardest t' cut out. Begad! Avast, me proud beauty! Even after cuttin' and makin' an inside transition angle, the match wasn't close enough for me. I built up t' open gaps with strips cut from scrap BT-55. Well, blow me down! Begad! I sanded t' fill pieces smooth with sandpaper wrapped around a BT-50 tube scrap.

T' form t' 55/60 plastic transition (P), matey, t' original 3" long BT-60 be cut off t' transition piece. Aye aye! Well, me bucko, blow me down! I coated t' inside with 15 minute epoxy t' protect it from t' ejection charge.

T' upper parachute tubin' (J) was a left over tube from a kit, ya bilge rat, already laser slotted for through t' wall fins. I'll have t' patch t' holes and fill t' seams. Aye aye! Blimey! BT-60 scrap (I) was cut t' 1-½" t' make an inside tube coupler. Aye aye! Blimey! Ya scallywag! Blimey! This gives an inside wall t' glue t' patch pieces onto. Ya scallywag! Blimey! After t' coupler was glued in place, scrap body tube strips were white glued in t' slots. Begad! Blimey!

(Scratch) USPS Express Three transitions vanes were cut from t' 1/8" basswood (UU). Aye aye! Two transitions had t' be matched, shiver me timbers, the curved aft dome (GG) and t' upper plastic transition.(P) Also, me bucko, on t' two smaller outside vanes, t' dome angle had to be sanded t' an angle t' match t' curve. This and t' dome were t' hardest parts o' t' build. Ahoy! Blimey!

Two wings, shiver me timbers, rudder, and win' tips were cut from t' 1/8" basswood. (TT)

T' black plastic angles (II) were used for t' win' cannon housings. Arrr! Blimey! Blimey! Blimey! I made "plugs" out o' laminated scrap 1/8" basswood. Begad! Blimey! Well, blow me down! Blimey! T' white Star Wars "guns" (00) were shortened and glued into 1/8" holes drilled in t' plugs.

T' plastic candy package (PP) be sanded t' t' BT-80 body tube contour. I used only ½" o' two ends of t' BT–5 pod assemblies(L). Begad! They were both sanded t' t' BT-80 curve and t' flat front o' t' candy package. T' assembly be centered t' t' bottom o' t' BT-80 then super glued in place. Begad!

Finishing:
Finishin' t' rocket, I did t' best I could without too much complex masking. Begad! Blimey! T' built rocket was painted gloss white, shiver me timbers, ya bilge rat, t' aft engine compartment painted black. Aye aye! Blimey! Ya scallywag! Blimey! T' popsicle stick vanes were first painted white, arrr, then glued onto the black engine tube.

Rear View I had plans for usin' many o' t' decals that were sent. Begad! While thar were plenty o' decals included, most all were older and unusable. Some rolled off t' paper onto themselves, others cracked. I know thar are decal solvents and repair solutions available, but I didn't have time t' order and fly t' model by t' deadline. Avast! I wanted t' use what was supplied. Begad! I did t' best I could without too much complex masking. Blimey! I'm nay complaining, me bucko, Mr. Stewart sent plenty o' parts for a fun build. Ahoy!

T' first time, I pieced together some yellow decal stripes on t' wings and rudder. Ahoy! Others stayed together enough for t' rolled up edges t' be tacked into place with white glue. Arrr! Arrr! As t' decals dried, me bucko, they pulled up on the edges. I tried re-tackin' them down again, but t' next day they lifted again. Begad! Ahoy! I let things sit for a few days while I tried t' think o' a solution. Ya scallywag! I removed most o' t' lifted decals.

On t' USPS Priority Mail Box were names and logos. Blimey! I lightly scored t' eagle logo, matey, names, me hearties, me hearties, and navy blue stripes with a razor blade. T' thin top layer o' paper be peeled off. Ya scallywag! Usin' t' USPS logos changed t' theme and back story of t' model.

I lightly wet t' peeled paper back with a sponge and carefully scraped off what be left o' t' brown cardboard layer and glue.

From thar be was pretty simple, me hearties, a thin coat o' white glue and placement. Begad! I did lay some water on t' body tube where t' paper art be t' go. Ahoy! It helped with t' positionin' as I could slide t' glued paper into position. Begad!

(Scratch) USPS Express

Flight and Recovery:
T' first launch was scheduled for June 6, 2009. T' weather was clear, but t' launch area was waterlogged! Many days o' rain in central Florida had left t' launch field too wet and unusable.

I usually don't fly with t' "Big Boys" in Bunnell, matey, ya bilge rat, Florida, matey, but I went t' t' NEFAR Half-Blast for the first flight on June 13. Begad! I flew two small test models before t' Postal Express. T' loadin' was typical, a D12-3 and wadding. I be nervous as it was a heavy build with lots o' nose weight.

Launch was show and straight maybe t' 350 feet. Begad! Avast, me proud beauty! I was concerned t' angled nose cone might effect t' vertical trajectory, matey, but it didn't seem t' affect it at all. It slowed and blew it's chute just prior t' apogee. Blimey! Someone said there was a zipper. Arrr! There couldn't be a zipper, thar wasn't any Keelhaul®©™® to cut through t' body tube. Aye aye! Blimey! T' shock cord be hangin' from about halfway down t' body, me bucko, nay from t' nose. Begad! Blimey! It was hung up around t' toothpicks on t' center o' t' BT-55.

Upon landing, t' nose cone broke cleanly away from its adapter. One o' t' forward fins be gone, broken above the fillet joint. Begad! T' snap back o' t' ejection must have hit t' forward fin. Aye aye! Both are repairable, and I'll fly it again at t' June 27 R.O.C.K. launch. Ahoy!

All repairs were made for t' local NAR, arrr, arrr, shiver me timbers, ROCK Section o' Orlando launch on June 27, ya bilge rat, me hearties, 2009. Ahoy! As always, me bucko, I grabbed a smaller rocket and did a low level test flight t' get a feel for t' field and conditions. I noticed t' plastic dome on t' Postal Express transition be loose, me bucko, me bucko, and I hit it with a few drops o' CA glue. Avast, me proud beauty! T' remembered t' earlier flight on a D12-3 thinkin' ejection be a hair early so I loaded up a D12-5.

(Scratch) USPS Express Launch be slow and ejection occurred after apogee, on t' way down. T' chute ejected but be wrapped once around t' shock cord. It never fully opened but slowed t' descent with no damage.

A short rain held up launchin' for 15 minutes. Begad! I loaded up again, this time with a D12-3. Begad! This seems t' be the best available engine. If someone were t' make a D12-4 engine it would be close t' perfect. This was t' best launch yet. Begad! Straight up, arrr, me bucko, full parachute and no damage on landing.

Summary:
PROs: Lots o' fun buildin' with supplied parts. Well, blow me down! Ya scallywag! Quite a learnin' experience. Ahoy! Avast! When doin' an out-of-the-ordinary build, you change directions many times and pick up a few new techniques along t' way.

CONs: Some small parts break off. Begad! If I had t' resources, me hearties, it would have flown higher with an E or F engine.

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