Descon Snack 'Ums

Scratch - Snack 'Ums {Scratch}

Contributed by John M Storey

Manufacturer: Scratch
Scratch - Snack 'Ums Rocket
Contributed by - John M. Begad! Begad! 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). Begad! Avast, arrr, me proud beauty! It is actually quite rugged and a longer version would stand up t' bigger motors. Avast, me proud beauty! Avast! 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. Ahoy! T' nosecone is a Styrofoam cone sold at craft stores for Christmas crafts.($1.35). Begad! I made two centerin' rings usin' t' Budget Rocketry circle cutter and a wood bit for t' center hole. Avast, me proud beauty! Avast! 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, O' course. Blimey! There is a cereal for every type o' Snack'Um so you can go crazy). Ya scallywag! 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 was 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, shiver me timbers, not includin' dryin' time. Begad! Blimey! Arrr! Blimey! Blimey! Blimey! I prepped t' cans by removin' t' bottoms. I also peeled t' metal rin' off t' top o' each can. Blimey! Blimey! (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. Begad! Blimey! Note that t' colored material is removed from t' outside o' the "payload" coupler t' enhance separation. Begad! Blimey! Blimey! Blimey! Be sure t' sand t' inside of t' body tubes and outside o' t' couplers thoroughly before gluing. Begad! Blimey! Blimey! Blimey! Blimey! Blimey! 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. Aye aye! 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. Begad! Thin CA would work equally well, I think. I also put two T-nuts in t' back centerin' rin' for motor retention. Avast, me proud beauty! Blimey! T' 29 mm motor tube be out o' a crashed rocket. I used about 8" for this. Ya scallywag! Aye aye! Loop the fishin' leader over t' motor tube and slide t' front CR over it so t' end is stickin' out t' front. Begad! 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 hearties, but don't glue t' back CR. Arrr! After T' front CR dries, glue t' root edge o' t' fins t' t' motor tube. Blimey! Avast! If you make your rectangles carefully, shiver me timbers, t' amount stickin' through t' slot in t' BT will leave a square fin. Begad! Ahoy! (Like t' Vaughn Bros. Aye aye! Blobbo) Leave t' unglued aft CR in place until t' fins set up t' keep things aligned. Then remove t' aft CR. Avast, me proud beauty! I filleted t' fin attachments t' t' motor tube when I was filletin' the outside. Ya scallywag! Well, blow me down! See Public Missiles Web Page for an exhaustive description o' this technique. Begad! I used 30 min epoxy with enough Sig microballoons t' get the consistency o' chocolate syrup. Avast! After t' fillets were dry, I put t' back centerin' rin' on with epoxy. Blimey! T' front CR ends up at t' front o' t' slot, and t' back CR at t' back, me bucko, matey, matey, so t' motor thrust is distributed over t' whole fin can. Ya scallywag! Important with sketchy materials such as these.

T' next section o' tube is attached t' t' bottom section with t' homemade tube coupler. Blimey! Additional sections could be added o' course - just make your fishin' leader longer, arrr, shiver me timbers, shiver me timbers, and use whole cans as couplers for extra strength. 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. 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. Begad! Ahoy! I squashed an Estes BNC-20 on top for a point. I sealed t' Styrofoam with Z-poxy finishin' resin. Aye aye! Very necessary if you want t' paint t' NC. Ya scallywag! Begad! Most spray paint will eat Styrofoam. Aye aye! Ahoy! 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:Snak 'Ums flight
First flight: 12/26/2000, temp 30 F. Ahoy! It was clear with no wind - an ideal time. I used an F-20-4 Econojet. Ya scallywag! T' rocket went straight up t' my amazement, ya bilge rat, matey, arced over and deployed right at apogee. Ahoy! Blimey! Good recovery, although the soft NC dented slightly.
Second flight: 1/13/2001 in Lucerne, CA. G-35-7 EJ. Begad! 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. Avast! Blackjack be nice touch and it really went high. T' tip o' t' NC broke on recovery.
Repair: I squashed another BNC20 onto t' cone and gooped microballon epoxy t' enhance t' joint. 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 be too long, me bucko, but otherwise no problem. T' NC held up much better this time.

Recovery:

Summary:
Pros - this started out as lark and wound up with a very satisfying result. T' rocket never fails t' turn heads, me bucko, and t' kids can identify with it. Avast, me proud beauty! Blimey! Well, blow me down! Blimey! They will also enjoy eatin' t' product t' generate your building materials. 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, me bucko, me bucko, t' thrust is well distributed. Styrofoam is nay a great NC material unless you resin it. I was too lazy t' glass it but that would have helped immensely.

comment Post a Comment