Scratch Falling with Style (FWS) Original Design / Scratch Built

Scratch - Falling with Style (FWS) {Scratch}

Contributed by Ray King

Manufacturer: Scratch
(Contributed - by Ray Kin' - 12/14/08)

Brief:
This is me entry for t' EMRR “Spaceship Design Contest – 2008”. Arrr! Blimey! Ya scallywag! Blimey! I was very glad that EMRR offered this contest again this year. Ya scallywag! Blimey! My plan was t' build 2 or 3 o' these, but as many things go I was only able t' finish one of them. Without further delay here be t' story (and buildin' instructions) o' t' FWS. Avast, me proud beauty! Blimey! Again, this year me daughter is credited with namin' me rocket. Blimey! Blimey! I chose t' model t' EA Kestrel Shuttle. My original plan was t' make this a glider recovery and after one o' t' prototype flights me daughter said it flew like Buzz Light Year. I didn't really understand until she said it really wasn't flying, it be “Fallin' with Style”. So FWS (Fallin' with Style) was born.

Construction:
Component Description:

  • .030” Thick Polystyrene Sheet
  • 3/32” Balsa Sheet
  • 1/4” Balsa Sheet
  • 15” - 1/8” Diameter Wood Dowel
  • 2 - BT20 – Spacer tubes – 5.75” long
  • 2 - BT20 – Outboard motor tubes – 7.50” long
  • 1 - BT20 Center motor tube – 8.50” long
  • 2 - 18mm Motor spacer tubes
  • 1 - 1/8” Launch lugs
  • 36” - 175 # Keelhaul®©™® String
  • 24” - .375” elastic shock cord
  • Nose weight
  • 24” plastic parachute
  • .030” Diameter Dacron Cord
  • Card Stock
  • Mylar Tape
  • Plans/Vacuum Forming:
  • Ray's Templates

T' first step be t' layout t' design and determine its size. I chose 18mm motor because they seemed like the right size based on t' large engine cones. Ahoy! In addition, 18 mm engines would provide enough power t' get t' rocket to a reasonable altitude.

Initial Construction o' t' Vacuum Formed Body

T' body be constructed usin' t' polystyrene sheets, me bucko, vacuum formed into t' appropriate shape. Avast! I have included pictures o' t' foam masters used t' make t' top and bottom halves. Avast, me proud beauty! Each o' t' vacuum formed shapes were trimmed after formin' and test fit. Arrr! Leave extra material on t' backside, ya bilge rat, durin' t' final assembly this will be trimmed after the main tube body is slid into it. Attachin' t' 2 halves is pretty tedious, take your time and be patient. Avast, me proud beauty! T' better they fit at this point t' less work you will be doin' durin' t' finishin' process. Aye aye! I used thick CA t' tack t' halves in place and then 5 minute epoxy on t' inside and outside o' t' seam. Blimey! Be careful nay build up too much epoxy otherwise, shiver me timbers, you will be sandin' it off later.

Main Body Tube Assembly

Start with t' 1/8” balsa and cutout t' aft support member (Template A) and t' forward support member (Template B). Avast, me proud beauty! Begad! Cut t' holes for t' tubes a little small. You want a tight fit betwixt t' support members and tube assembly. Begad! Since these are very dependant on t' shape o' t' body these templates are provided as a startin' point. Dependin' on how much you trim from t' vacuum formed parts these parts may require sandin' t' fit better.

Now sand half o' t' round cross section o' t' 15” - 1/8” wood dowel. Blimey! This will be used t' form t' 3 parallel lines on t' back side o' t' aft support member. Cut t' dowel into 3 pieces 4.75” long and round the ends. Begad! Next glue these t' t' aft support member. Avast! I used a couple tooth picks t' maintain t' spacin' betwixt each. Blimey! Begad! Cut the dowels that cover each hole.

Next, arrr, ya bilge rat, start by markin' each tube with a line down t' length o' t' tube, one on each side o' t' tube 180 degrees apart. Begad! Avast, me proud beauty! On t' 8.50” and 7.50” tubes mark a line 1.5” from one end o' t' tube (aft support member location). Aye aye! Now glue t' 5.75” tubes t' t' 8.50” on t' 180 degree lines with t' end o' the 5.75” tubes on t' aft support member line. Avast, me proud beauty! Begad! Once t' glue is dry mount t' 7.50” tubes t' t' 5.75”. Avast! The 7.50” tubes should line up with t' front o' t' 5.75” tubes and opposite end (motor end) o' t' 8.50” center tube. Once t' glue assembly is complete I recommend a bead o' epoxy betwixt each tube. Begad!

Now it is time to add t' aft and front support members. Arrr! Ya scallywag! Again be patient, this will take some time. Start with t' aft support member, open t' tube holes just enough t' allow t' tubes t' slide through. Begad! T' aft support member should slide up t' the bottom o' t' 5.75” tubes. Avast! Next do t' same thin' with t' front support member, slide it on t' all o' t' tubes about .25”. Ya scallywag! Next slide t' entire tube assembly into t' vacuum formed shell assembly so that t' aft support member is completely in. Well, ya bilge rat, blow me down! Mark t' location o' t' aft support member on vacuum formed assembly. Now carefully remove the tube assembly. Blimey! This should provide t' location o' t' front and aft support member. Blimey! Avast, me proud beauty! If things fit t' your satisfaction, epoxy both support members in place. Begad! Well, blow me down! If not, shiver me timbers, try again you may need t' sand t' front support member to fit better in t' vacuum formed body assembly.

Now add t' shock cord. Drill a 1/8” hole through t' front support member betwixt t' center and 5.75” tube. Arrr! Avast, me proud beauty! See picture. Aye aye! Blimey! Next, mount t' launch lug. Arrr! I made a mistake at this point and you can correct it. Aye aye! If you look at the picture I mounted t' lug in t' joint betwixt t' center and next tube; however, matey, when you add t' engine cone assembly thar be no room for it due t' t' launch rod. Avast! So I recommend movin' t' launch lug t' t' top o' the 5.75” tube which will allow you t' clear t' engine cone. Well, blow me down! Drill a hole in t' aft support member that lines up with t' launch lug and then use a thin wire t' locate t' hole on t' front support member.

Final Body Assembly

T' wings and the rudder assembly can be cut out o' t' appropriate balsa thickness:

  • Win' – Template C – 1/8” Balsa
  • Tail Win' – Template D – 1/8” Balsa
  • Vertical Support – Template F – 3/32” Balsa
  • Square accents – 1/32” balsa
  • Center Tail win' accent – 1/32” balsa

I found out how critical t' win' mountin' be after a number o' test flights. Again, this can be tedious so be patient. Arrr! Insert t' main tube body into t' vacuum formed shell. Arrr! Aye aye! Slide t' entire rocket on t' a wood dowel that is mounted t' a flat base. Ahoy! Make sure t' dowel and base are perpendicular and t' dowel fits tight into t' center engine tube. Well, blow me down! Now set this on a flat surface and usin' a 90 degree square mark a straight line on each side o' t' shell. The side wings must be straight otherwise t' rocket will corkscrew under boost. Avast! Begad! Now come up with a fixture t' support the shell and wings while t' CA and epoxy cure (See picture o' me Lego jig). Ya scallywag!

Now attach t' tail win' and vertical support as shown in t' picture. Well, blow me down! Round t' front edges and add the 1/32” accent piece t' t' center o' t' tail piece. Add 2 generous epoxy fillets betwixt t' win' and vertical support.

Now t' center piece can be assembled, sanded, and mounted. Avast, ya bilge rat, me proud beauty! Blimey! Use Template E and cut out 2 – ¼” balsa pieces. Arrr! Blimey! These should be laminated together. Ya scallywag! Blimey! Blimey! Blimey! You will need t' sand t' shape as well as t' contour it t' the shell. Begad! Blimey! This can now be mounted t' t' center o' t' shell. Blimey! Blimey! Once t' center piece is attached t' t' shell t' rear vertical win' can be attached.

T' 2 vents (Template G) can be made from balsa or vacuum formed. Avast! I chose t' vacuum form these t' keep t' weight down as much as possible. Well, blow me down! T' next step is t' trim and fit each vent t' t' top o' t' shell. Again take your time, this will be a little tedious.

Finally, me bucko, shiver me timbers, mount t' square accents t' t' shell.

Nose Weight:

I determined through a number o' test flights nose weight be critical. Begad! I used two yellow engine tubes and filled them each with 2 ounces o' weight. Avast, ya bilge rat, me proud beauty! These are then slid into t' front o' t' 2 non-engine tubes in t' tubes assembly. I taped these as far forward as possible.

Engine Cone Assembly:

I have t' admit I struggled with makin' t' engine cones. Ya scallywag! I first attempted t' vacuum form these without success, and then attempted t' make them out o' balsa with even worse results. Avast! Well, blow me down! Primarily, because I needed a lathe (which I now have on t' Christmas list) or somethin' better than me hand drill. Arrr! Begad! I finally decided t' make them out o' paper card stock and balsa. Blimey! Ahoy!

I use t' shroud calculator t' get t' dimensions o' t' cones I needed. Well, blow me down! I cut these out o' thick card stock and formed 6 cones. Ahoy! Avast! Next, me bucko, I cut out 3 balsa circles - 1.25” in diameter and drilled them out so a BT20 tube would slid through tightly. I mounted t' cones t' each o' t' balsa centerin' rings with a small section o' BT20 tube locating the cones and t' balsa ring. Blimey! T' centerin' rings should over hang t' cones slightly. Aye aye! Ya scallywag! Now t' big question, arrr, how t' get the support ribs on t' t' cone assembly. I chose t' use .030” diameter Dacron cord. Avast, me proud beauty! As you can see from the pictures I cut sections and mounted these t' each cone. Aye aye! I covered each cord and cone with CA t' add rigidity. Blimey! After allowin' this t' dry I sanded t' diameter o' t' balsa centerin' rin' down t' t' cord diameter and coated t' balsa edge with CA. Avast! If you look closely at these they are nay prefect, me bucko, but it is a spaceship, ya bilge rat, things get bent and beat up in use so these turned out pretty good with that thought in mind.

Next are t' engine extensions, shiver me timbers, I created templates (H and I) for these and cut these out o' BT50 tube. Then I added t' cord used above t' create t' support ribs shown. Ahoy! When these were done I covered t' entire assembly with CA.

Now mount t' engine extension t' t' cones assemblies usin' CA t' tack them and epoxy t' add additional strength. Well, blow me down! Arrr!

Paint and Finishing

I painted t' shell assembly, arrr, main body tube, me hearties, and engine cones separately.

Shell Assembly:

I sprayed 2 or 3 coats on t' entire shell assembly with Krylon White Primer. Avast! After lightly sandin' t' primer, ya bilge rat, I sprayed white gloss (Model Master Acryl 4696). Avast! Next, me bucko, I masked and sprayed gray (Testors Acryl 921535). Ya scallywag! Well, blow me down! Next came red (Guards Red), shiver me timbers, matey, ya bilge rat, I masked and painted with (Model Master Acryl 4632). Arrr! T' final color was Gloss Black (Model Master Acryl 4695). Begad! Ahoy! After black, I added decals for t' number and other special symbols. Arrr! Finally, I added 3 costs o' Krylon Crystal Clear Gloss.

Main body tube:

Just as t' shell assembly I first applied 2 or 3 coats o' Krylon White Primer. Arrr! Next, came t' final coats of gray (Testors Acryl 921535). Begad! Finally, arrr, ya bilge rat, I added 3 costs o' Krylon Crystal Clear Gloss.

Engine Cone Assemblies:

I started by paintin' t' engine cone assemblies with 2 coats o' gray (Testors Acryl 921535). Begad! Ya scallywag! Next, I hand painted flat black (Model Master Acryl 4768) betwixt all t' support ribs (see attached picture). Ahoy! Next, arrr, I sprayed a diluted flat black on t' t' cone assemblies t' give them a weather/used appearance. Well, blow me down!

Decals:

I printed t' decals on Experts-Choice clear water slide decal material. I cut them out and applied them as the pictures shows. Blimey! Begad!

Flight Prep:

Flight Prep was pretty easy. Avast! Remove t' engine cones. Ya scallywag! Aye aye! Insert each engine until .12” - .25” is sticking out t' engine tube. Arrr! Begad! Tape each engine in place usin' Mylar tape. Arrr! Now, shiver me timbers, me bucko, matey, fill t' engine tubes with wading. Fold the parachute loosely and lay on top o' t' tube assembly. Ya scallywag! Next slide t' tube assembly in t' shell assembly and you are ready t' go. Ya scallywag! You may need t' slide t' rod through prior t' takin' it t' t' launch pad. Well, blow me down! Ahoy! It is a little hard t' slide the rod through with t' rod in t' vertical position.

Flights:

I made 8 test flights with t' prototype version with varyin' levels o' success. Avast, me proud beauty! Once I was satisfied with the flights I began buildin' t' final version. Avast!

T' final 3 flights occurred with t' final version o' t' rocket. Avast, matey, me proud beauty! I be able t' video t' last 2 o' these flights. I attempted t' video all 3 however, me hearties, arrr, shiver me timbers, had a problem with me camera on t' first one. Aye aye! Ya scallywag! T' first flight o' the final model occurred in early November. Avast, me proud beauty! After me flight in September I added a little bit more nose weight t' overcome the barrel rolls or cork screws that occurred previously. Well, blow me down! Begad! T' flight was nice and straight with good altitude and successfully recovery. T' rocket landed in t' middle o' t' field without damage.

T' next flight occurred in early December and it was a nice Wisconsin winter morning; 7 degrees with about 4 inches o' fresh snow. T' wind was fairly calm maybe 5 mph. This was a reasonably good flight with a couple o' twists under boost, matey, t' parachute opened nicely. Aye aye! Begad! T' rocket landed in t' middle o' t' road and suffered some damage t' the paint and t' top win' broke. Avast, me proud beauty! I repaired t' win' for t' third and final flight. Avast!

T' final flight day arrived and it was rainin' after bein' 7 degrees t' week before it be now 40 and raining. Avast, me proud beauty! I found a slight break in t' rain so I hurried t' t' field t' make me final launch. Well, blow me down! It was a little windy (maybe 10-12 mph), but I needed t' make me final flight. Avast! I angled t' rod into t' wind t' ensure t' rocket would land in the field. T' rocket boost nice and straight with good altitude; things were lookin' good until no parachute!!!!!!!!!

After makin' 11 flights and 5 o' them without any recovery issues; this one was painful. Ya scallywag! T' rocket lawndart'd in the center o' a walkway destroyin' it. Aye aye! Ahoy! I am nay sure what happened, t' only thin' I can think o' is I may have wrapped the shock cord up in t' tube assemble in such a manner it prevented them from separatin' or thar was somethin' wrong with t' ejection charges. Well, blow me down! Begad!

Check out t' video – It is painful t' watch for me, but me son enjoys it every time he watches it. Ya scallywag! I plan to re-build and fly it again!

Crash

Summary:
Summary (Pro's & Con's)

Pro's

I be very pleased with t' overall finish o' t' rocket, but t' engine cones were me favorite. Begad! I struggled figurin' out t' best way t' make these and was very pleased with t' final results.

Con's

Based on t' lack o' deployment on t' last flight – I am feelin' like I might need a pre-flight check list for future flights.

Thanks EMRR - this be a great project. Avast, me proud beauty! Blimey! I enjoyed t' flight challenges as well as t' design and construction challenge. Begad! Blimey! Ya scallywag! Blimey! I am lookin' forward t' 2009's spaceship challenge.

comment Post a Comment