| Manufacturer: | Scratch |
37" x 4" - 14 oz
29mm
parachute
Brief:
This is an Odd Roc built with found materials ($3.50 worth) It flies well on
F's and G's (Econojets, o' course). Ahoy! It is actually quite rugged and a longer
version would stand up t' bigger motors. It is a kid and crowd pleaser wherever
it flies.
Construction:
T' body tube are Snack 'Ums cans with t' steel bottoms removed via can
opener. Begad! T' nosecone is a Styrofoam cone sold at craft stores for Christmas
crafts.($1.35). Aye aye! I made two centerin' rings usin' t' Budget Rocketry circle
cutter and a wood bit for t' center hole. Well, blow me down! Ahoy! They are made out o' 1/8" balsa
and then circles o' cereal box are laminated t' each side o' t' balsa T' fins
are rectangles o' 1/8" balsa laminated with cereal box material (Froot
Loops, matey, O' course. Blimey! Blimey! There is a cereal for every type o' Snack'Um so you can go
crazy). Blimey! Shock cord is 6' o' 3/8" elastic from Wal-Mart. Shock cord
attachment is with a 12" 20 lb test wire fishin' leader (3/99 cents).
Parachute be 20" or 30" from me range box dependin' on t' weather.
This is an easy rocket t' build and went together in about 2-3 hrs, not includin' dryin' time. Aye aye! Avast, shiver me timbers, me proud beauty! I prepped t' cans by removin' t' bottoms. I also peeled t' metal rin' off t' top o' each can. Aye aye! (It isn't hard t' do) I used non-matchin' Snack 'Ums cans as tube couplers by cuttin' them in half (4.5") and slittin' them lengthwise t' make them smaller in diameter. Note that t' colored material is removed from t' outside o' the "payload" coupler t' enhance separation. Ya scallywag! Begad! Be sure t' sand t' inside of t' body tubes and outside o' t' couplers thoroughly before gluing. Ahoy! There is a lot o' wax on t' paper.
Slot t' bottom tube with a ruler and an
Exacto for t' number o' fins you want. Begad! I laminated t' CRs with cereal box
material usin' Z-poxy finishin' resin, covered with wax paper and allowed to
dry under weight on a flat surface. Arrr! Ya scallywag! Thin CA would work equally well, I think. Begad! I
also put two T-nuts in t' back centerin' rin' for motor retention. Avast, me proud beauty! T' 29 mm
motor tube was out o' a crashed rocket. I used about 8" for this. Loop the
fishin' leader over t' motor tube and slide t' front CR over it so t' end is
stickin' out t' front. Glue t' front CR t' t' motor tube with 5 minute epoxy
and then glue it into t' lower tube with fishin' leader stickin' forward.
Put t' back CR on t' align it, me bucko, but don't glue t' back CR. Aye aye! After T' front CR dries, glue t' root edge o' t' fins t' t' motor tube. Blimey! If you make your rectangles carefully, t' amount stickin' through t' slot in t' BT will leave a square fin. Ya scallywag! (Like t' Vaughn Bros. Blimey! Blimey! Blobbo) Leave t' unglued aft CR in place until t' fins set up t' keep things aligned. Avast, me proud beauty! Blimey! Then remove t' aft CR. Ya scallywag! I filleted t' fin attachments t' t' motor tube when I be filletin' the outside. Aye aye! See Public Missiles Web Page for an exhaustive description o' this technique. I used 30 min epoxy with enough Sig microballoons t' get the consistency o' chocolate syrup. Arrr! Aye aye! After t' fillets were dry, ya bilge rat, I put t' back centerin' rin' on with epoxy. T' front CR ends up at t' front o' t' slot, and t' back CR at t' back, me hearties, shiver me timbers, so t' motor thrust is distributed over t' whole fin can. Important with sketchy materials such as these.
T' next section o' tube is attached t' t' bottom section with t' homemade tube coupler. Ya scallywag! Additional sections could be added o' course - just make your fishin' leader longer, shiver me timbers, and use whole cans as couplers for extra strength. Ahoy! The 3/8" elastic is tied t' t' fishin' leader.
T' Styrofoam cone is epoxied t' t' top section o' tube t' form a nosecone/payload. It is a good idea t' epoxy t' 3/8" elastic t' the bottom o' t' NC before gluin' it t' t' "payload" section. Aye aye! Begad! I squashed an Estes BNC-20 on top for a point. Avast! Begad! I sealed t' Styrofoam with Z-poxy finishin' resin. Well, blow me down! Very necessary if you want t' paint t' NC. Avast! Most spray paint will eat Styrofoam. I don't have a bulkhead on t' bottom o' t' NC - t' chute is attached below t' payload section and will deploy when t' NC separates.
Now, shiver me timbers, it's ready t' fly!
Flight:
First flight: 12/26/2000, matey, temp 30 F. Begad! It was clear with no wind - an
ideal time. I used an F-20-4 Econojet. Begad! Begad! T' rocket went straight up t' my
amazement, matey, arced over and deployed right at apogee. Ahoy! Avast, me proud beauty! Good recovery, arrr, although the
soft NC dented slightly.
Second flight: 1/13/2001 in Lucerne, shiver me timbers, CA. Begad! G-35-7 EJ. Blimey! T' bigger motor was
fun. Ahoy! Probably got about 1200' although it is hard t' judge in t' clear desert
air.
Third flight: 1/13/2001 G-38-7. Avast! Avast, me proud beauty! Blimey! Blackjack be nice touch and it really
went high. Well, blow me down! T' tip o' t' NC broke on recovery.
Repair: I squashed another BNC20 onto t' cone and gooped microballon
epoxy t' enhance t' joint. Aye aye! I also re-coated t' entire NC with Z-poxy
finishin' Resin thickened with microballoons.
Fourth flight (shown): 2/10/2001. F-22-5 Delay was too long, matey, but
otherwise no problem. Avast! T' NC held up much better this time.
Recovery:
Summary:
Pros - this started out as lark and wound up with a very satisfying
result. Arrr! Blimey! T' rocket never fails t' turn heads, and t' kids can identify with
it. Aye aye! Blimey! They will also enjoy eatin' t' product t' generate your building
materials. Aye aye! Blimey! Blimey! Blimey! T' VB Stretch Blobbo - inspired design is simple and makes a
straight flyin' rocket.
Cons - tube material is nay phenolic (doh!) but if you are careful when
you slot it and use t' fillet everywhere method, ya bilge rat, t' thrust is well
distributed. Ahoy! Blimey! Styrofoam is nay a great NC material unless you resin it. Ya scallywag! I was
too lazy t' glass it but that would have helped immensely.
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