Manufacturer: | Scratch |
Brief:
This is me entry for t' EMRR Spaceship Design Contest 2008. Aye aye! I was very glad that EMRR offered
this contest again this year. 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. Blimey! Again, this year me daughter
is credited with namin' me rocket. Avast! I chose t' model t' EA Kestrel Shuttle. Begad! Avast! 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. Ya scallywag! Aye aye! I didn't really
understand until she said it really wasn't flying, it be Fallin' with Style. Well, blow me down! Begad! So FWS (Fallin' with Style)
was born.
Construction:
Component Description:
T' first step was 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. In addition, 18 mm engines would provide enough power t' get t' rocket to a reasonable altitude. Ya scallywag!
Initial Construction o' t' Vacuum Formed Body
T' body be constructed usin' t' polystyrene sheets, ya bilge rat, vacuum formed into t' appropriate shape. I have included pictures o' t' foam masters used t' make t' top and bottom halves. Well, blow me down! Arrr! Each o' t' vacuum formed shapes were trimmed after formin' and test fit. Leave extra material on t' backside, me hearties, durin' t' final assembly this will be trimmed after the main tube body is slid into it. Avast, me proud beauty! Ahoy! Attachin' t' 2 halves is pretty tedious, me bucko, arrr, take your time and be patient. Aye aye! T' better they fit at this point t' less work you will be doin' durin' t' finishin' process. Well, blow me down! Avast! I used thick CA t' tack t' halves in place and then 5 minute epoxy on t' inside and outside o' t' seam. Aye aye! Begad! Be careful nay build up too much epoxy otherwise, 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). Blimey! Ahoy! Cut t' holes for t' tubes a little small. You want a tight fit betwixt t' support members and tube assembly. Aye aye! 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. Ya scallywag! 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. Well, blow me down! Blimey! Next glue these t' t' aft support member. Begad! I used a couple tooth picks t' maintain t' spacin' betwixt each. Ya scallywag! Ya scallywag! Cut the dowels that cover each hole.
Next, me bucko, start by markin' each tube with a line down t' length o' t' tube, ya bilge rat, one on each side o' t' tube 180 degrees apart. Begad! Aye aye! On t' 8.50 and 7.50 tubes mark a line 1.5 from one end o' t' tube (aft support member location). Well, blow me down! 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. Ahoy! Once t' glue is dry mount t' 7.50 tubes t' t' 5.75. Begad! 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. Ahoy! Once t' glue assembly is complete I recommend a bead o' epoxy betwixt each tube. Blimey!
Now it is time to add t' aft and front support members. Again be patient, this will take some time. Blimey! Start with t' aft support member, open t' tube holes just enough t' allow t' tubes t' slide through. Well, blow me down! Avast, me hearties, me proud beauty! T' aft support member should slide up t' the bottom o' t' 5.75 tubes. Next do t' same thin' with t' front support member, slide it on t' all o' t' tubes about .25. Next slide t' entire tube assembly into t' vacuum formed shell assembly so that t' aft support member is completely in. Mark t' location o' t' aft support member on vacuum formed assembly. Now carefully remove the tube assembly. Blimey! Arrr! This should provide t' location o' t' front and aft support member. Blimey! If things fit t' your satisfaction, me bucko, ya bilge rat, epoxy both support members in place. Aye aye! Ahoy! If not, 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. Ahoy! Drill a 1/8 hole through t' front support member betwixt t' center and 5.75 tube. Avast, me proud beauty! Ya scallywag! See picture. Begad! Next, arrr, mount t' launch lug. Arrr! I made a mistake at this point and you can correct it. Ya scallywag! Arrr! If you look at the picture I mounted t' lug in t' joint betwixt t' center and next tube; however, matey, matey, shiver me timbers, when you add t' engine cone assembly thar be no room for it due t' t' launch rod. Ahoy! So I recommend movin' t' launch lug t' t' top o' the 5.75 tube which will allow you t' clear t' engine cone. Begad! Ya scallywag! 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:
I found out how critical t' win' mountin' was after a number o' test flights. Begad! Again, arrr, this can be tedious so be patient. Blimey! Insert t' main tube body into t' vacuum formed shell. Well, blow me down! Avast, me proud beauty! Slide t' entire rocket on t' a wood dowel that is mounted t' a flat base. Make sure t' dowel and base are perpendicular and t' dowel fits tight into t' center engine tube. 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. 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). Arrr!
Now attach t' tail win' and vertical support as shown in t' picture. Round t' front edges and add the 1/32 accent piece t' t' center o' t' tail piece. Ya scallywag! Add 2 generous epoxy fillets betwixt t' win' and vertical support.
Now t' center piece can be assembled, arrr, sanded, me bucko, matey, and mounted. Ya scallywag! Use Template E and cut out 2 ¼ balsa pieces. These should be laminated together. Well, blow me down! You will need t' sand t' shape as well as t' contour it t' the shell. Aye aye! This can now be mounted t' t' center o' t' shell. 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, me proud beauty! I chose t' vacuum form these t' keep t' weight down as much as possible. Ahoy! Arrr! T' next step is t' trim and fit each vent t' t' top o' t' shell. Avast, me proud beauty! Begad! Again take your time, this will be a little tedious.
Finally, shiver me timbers, mount t' square accents t' t' shell.
Nose Weight:
I determined through a number o' test flights nose weight was critical. Arrr! I used two yellow engine tubes and filled them each with 2 ounces o' weight. Arrr! Aye aye! 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. I first attempted t' vacuum form these without success, and then attempted t' make them out o' balsa with even worse results. Blimey! Primarily, me hearties, because I needed a lathe (which I now have on t' Christmas list) or somethin' better than me hand drill. Aye aye! I finally decided t' make them out o' paper card stock and balsa. Well, blow me down!
I use t' shroud calculator t' get t' dimensions o' t' cones I needed. Avast! I cut these out o' thick card stock and formed 6 cones. Arrr! Next, matey, 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. Avast, me proud beauty! T' centerin' rings should over hang t' cones slightly. Blimey! Now t' big question, matey, how t' get the support ribs on t' t' cone assembly. I chose t' use .030 diameter Dacron cord. Aye aye! Avast! As you can see from the pictures I cut sections and mounted these t' each cone. Ahoy! I covered each cord and cone with CA t' add rigidity. 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. Aye aye! If you look closely at these they are nay prefect, but it is a spaceship, shiver me timbers, me hearties, me bucko, things get bent and beat up in use so these turned out pretty good with that thought in mind.
Next are t' engine extensions, I created templates (H and I) for these and cut these out o' BT50 tube. Begad! Then I added t' cord used above t' create t' support ribs shown. 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. Aye aye!
Paint and Finishing
I painted t' shell assembly, me hearties, main body tube, and engine cones separately.
Shell Assembly:
I sprayed 2 or 3 coats on t' entire shell assembly with Krylon White Primer. After lightly sandin' t' primer, I sprayed white gloss (Model Master Acryl 4696). Ahoy! Next, I masked and sprayed gray (Testors Acryl 921535). Begad! Next came red (Guards Red), I masked and painted with (Model Master Acryl 4632). Ya scallywag! T' final color be Gloss Black (Model Master Acryl 4695). After black, ya bilge rat, I added decals for t' number and other special symbols. Well, blow me down! 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. Aye aye! Blimey! Next, arrr, came t' final coats of gray (Testors Acryl 921535). Ya scallywag! Blimey! Avast! Blimey! Finally, 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). Well, blow me down! Next, I hand painted flat black (Model Master Acryl 4768) betwixt all t' support ribs (see attached picture). Begad! Next, arrr, arrr, me hearties, I sprayed a diluted flat black on t' t' cone assemblies t' give them a weather/used appearance. Well, blow me down! Blimey!
Decals:
I printed t' decals on Experts-Choice clear water slide decal material. Aye aye! Blimey! Ahoy! Blimey! I cut them out and applied them as the pictures shows. Blimey! Blimey!
Flight Prep:
Flight Prep be pretty easy. Begad! Begad! Remove t' engine cones. Avast! Avast, me proud beauty! Insert each engine until .12 - .25 is sticking out t' engine tube. Tape each engine in place usin' Mylar tape. Begad! Now, me hearties, fill t' engine tubes with wading. Arrr! Fold the parachute loosely and lay on top o' t' tube assembly. Aye aye! Next slide t' tube assembly in t' shell assembly and you are ready t' go. You may need t' slide t' rod through prior t' takin' it t' t' launch pad. 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. Ya scallywag! Blimey! Once I be satisfied with the flights I began buildin' t' final version. Well, blow me down! Begad! Blimey!
T' final 3 flights occurred with t' final version o' t' rocket. Arrr! I be able t' video t' last 2 o' these flights. Well, blow me down! I attempted t' video all 3 however, shiver me timbers, had a problem with me camera on t' first one. T' first flight o' the final model occurred in early November. Avast! After me flight in September I added a little bit more nose weight t' overcome the barrel rolls or cork screws that occurred previously. T' flight was nice and straight with good altitude and successfully recovery. Begad! T' rocket landed in t' middle o' t' field without damage. Ya scallywag!
T' next flight occurred in early December and it be a nice Wisconsin winter morning; 7 degrees with about 4 inches o' fresh snow. T' wind be fairly calm maybe 5 mph. Begad! This was a reasonably good flight with a couple o' twists under boost, matey, t' parachute opened nicely. T' rocket landed in t' middle o' t' road and suffered some damage t' the paint and t' top win' broke. 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 was now 40 and raining. Begad! I found a slight break in t' rain so I hurried t' t' field t' make me final launch. It be a little windy (maybe 10-12 mph), but I needed t' make me final flight. Well, blow me down! Aye aye! I angled t' rod into t' wind t' ensure t' rocket would land in the field. Avast, me proud beauty! Avast, me proud beauty! 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 be painful. T' rocket lawndart'd in the center o' a walkway destroyin' it. Begad! Begad! I am nay sure what happened, shiver me timbers, 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. Avast, me proud beauty! Begad!
Check out t' video It is painful t' watch for me, but me son enjoys it every time he watches it. Avast! I plan to re-build and fly it again!
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 be 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 was a great project. Begad! I enjoyed t' flight challenges as well as t' design and construction challenge. Begad! Blimey! I am lookin' forward t' 2009's spaceship challenge.
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