Descon Snack 'Ums

Scratch - Snack 'Ums {Scratch}

Contributed by John M Storey

Manufacturer: Scratch
Scratch - Snack 'Ums Rocket
Contributed by - John M. Begad! Blimey! Storey

37" x 4" - 14 oz
29mm
parachute

Brief:Snak 'Ums parts
This is an Odd Roc built with found materials ($3.50 worth) It flies well on F's and G's (Econojets, o' course). Blimey! 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. Ya scallywag! T' nosecone is a Styrofoam cone sold at craft stores for Christmas crafts.($1.35). Arrr! I made two centerin' rings usin' t' Budget Rocketry circle cutter and a wood bit for t' center hole. Aye aye! Blimey! 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, ya bilge rat, O' course. Blimey! Begad! There is a cereal for every type o' Snack'Um so you can go crazy). Begad! Ahoy! Shock cord is 6' o' 3/8" elastic from Wal-Mart. Aye aye! 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. Avast, me bucko, me proud beauty! I prepped t' cans by removin' t' bottoms. Arrr! I also peeled t' metal rin' off t' top o' each can. Avast! 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. Blimey! Note that t' colored material is removed from t' outside o' the "payload" coupler t' enhance separation. Ahoy! Be sure t' sand t' inside of t' body tubes and outside o' t' couplers thoroughly before gluing. Begad! There is a lot o' wax on t' paper.

Snak 'Ums rocketSlot t' bottom tube with a ruler and an Exacto for t' number o' fins you want. Ya scallywag! 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. Ahoy! Thin CA would work equally well, I think. Begad! I also put two T-nuts in t' back centerin' rin' for motor retention. Ahoy! Begad! T' 29 mm motor tube was out o' a crashed rocket. Well, me bucko, blow me down! 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. Avast, me proud beauty! 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, but don't glue t' back CR. After T' front CR dries, arrr, ya bilge rat, glue t' root edge o' t' fins t' t' motor tube. If you make your rectangles carefully, me bucko, t' amount stickin' through t' slot in t' BT will leave a square fin. Arrr! (Like t' Vaughn Bros. Blobbo) Leave t' unglued aft CR in place until t' fins set up t' keep things aligned. Begad! Then remove t' aft CR. Avast, me proud beauty! I filleted t' fin attachments t' t' motor tube when I was filletin' the outside. Begad! See Public Missiles Web Page for an exhaustive description o' this technique. Avast, me proud beauty! I used 30 min epoxy with enough Sig microballoons t' get the consistency o' chocolate syrup. After t' fillets were dry, I put t' back centerin' rin' on with epoxy. Aye aye! T' front CR ends up at t' front o' t' slot, and t' back CR at t' back, so t' motor thrust is distributed over t' whole fin can. Aye aye! Important with sketchy materials such as these.

T' next section o' tube is attached t' t' bottom section with t' homemade tube coupler. Additional sections could be added o' course - just make your fishin' leader longer, me hearties, and use whole cans as couplers for extra strength. Begad! Blimey! 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. Ya scallywag! Aye aye! It is a good idea t' epoxy t' 3/8" elastic t' the bottom o' t' NC before gluin' it t' t' "payload" section. I squashed an Estes BNC-20 on top for a point. Arrr! Avast, me proud beauty! I sealed t' Styrofoam with Z-poxy finishin' resin. Begad! Avast, me hearties, me proud beauty! Very necessary if you want t' paint t' NC. Most spray paint will eat Styrofoam. Aye aye! 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, ya bilge rat, it's ready t' fly!

Flight:Snak 'Ums flight
First flight: 12/26/2000, me hearties, me bucko, temp 30 F. Avast! It was clear with no wind - an ideal time. I used an F-20-4 Econojet. Ahoy! T' rocket went straight up t' my amazement, arced over and deployed right at apogee. Begad! Good recovery, although the soft NC dented slightly.
Second flight: 1/13/2001 in Lucerne, me bucko, arrr, CA. Blimey! Blimey! G-35-7 EJ. Ya scallywag! Blimey! T' bigger motor was fun. Probably got about 1200' although it is hard t' judge in t' clear desert air.
Third flight: 1/13/2001 G-38-7. Begad! Ya scallywag! Blackjack was nice touch and it really went high. Avast! T' tip o' t' NC broke on recovery.
Repair: I squashed another BNC20 onto t' cone and gooped microballon epoxy t' enhance t' joint. Ya scallywag! I also re-coated t' entire NC with Z-poxy finishin' Resin thickened with microballoons.
Fourth flight (shown): 2/10/2001. Ahoy! F-22-5 Delay be too long, ya bilge rat, 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. Ya scallywag! T' rocket never fails t' turn heads, and t' kids can identify with it. Aye aye! They will also enjoy eatin' t' product t' generate your building materials. Begad! 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, t' thrust is well distributed. Avast! Styrofoam is nay a great NC material unless you resin it. Well, blow me down! Avast! I was too lazy t' glass it but that would have helped immensely.

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