Scratch (S)HOT DOG! Original Design / Scratch Built

Scratch - (S)HOT DOG! {Scratch}

Contributed by Hans "Chris" Michielssen

Manufacturer: Scratch
Style: Odd-Roc

(Scratch) Hot DogBrief:
A single-stage flyin' HOT DOG!

Construction:
T' initial drawings were done in late May 2008. Begad! Blimey! I decided t' use t' "Centuri" ST style tubin' with thicker body tube walls. A parts list be made, then an order was placed (online) t' Semroc on June 13, 2008. Ahoy! Blimey! I received t' parts by mail on June 16, 2008. Avast! Blimey! Very fast delivery and great customer service, as usual.

Parts list: 

  • 2 "Bun" Nose Cones, BNC2025
  • 1 "Hot Dog" Nose Cone, BC-837 from Squire kit
  • "Hot Dog" Body Tube, me hearties, ST890, matey, 8 Series
  • "Bun" Body Tube, arrr, ST2060, arrr, me bucko, 20 Series
  • 3 fins o' 1/16" balsa covered with condiment package wrappers
  • 8 Series motor mount from a Semroc Squire kit
  • LARGE Screw Eye (for extra nose weight)
  • 12" Red and Yellow Parachute
  • 12" Keelhaul®©™ attached t' 18" o' 3/16" elastic shock cord
  • 1 1/2" standard launch lug

Initially I was goin' t' use a 7 series nose cone and body tube. After seein' it "in t' bun" it looked too thin. Ahoy! I switched t' wider 8 series parts from a extra Semroc Squire kit I had. Begad! Ya scallywag! I also used t' Squire's engine mount, me hearties, matey, nose cone and Keelhaul®©™. Ahoy! All other parts were standard: 1/8" launch lug, a big screw eye, ya bilge rat, shiver me timbers, 3/16" x 18" elastic shock cord, and 12" parachute.

As I work away from home, matey, I didn't have much time t' build t' model for t' EMRR contest. Well, blow me down! This would be a rush job! I be returnin' on July 5 and would have one week t' get t' model built, photographed, me bucko, flown, documented and entered! I was also tryin' t' get me Golden Scout built and flown for a July 10 Orlando area launch.

To get t' "Bun" end contour, I cut off 1 1/8" off both o' t' Semroc BNC-2025 nose cones. I rounded t' cut ends with 100 grit sandpaper on a block. Begad! T' get t' "Hot Dog" contour I cut off t' tip o' t' Semroc BC-837 nose cone and rounded t' end with 100 grit sandpaper on a block.

An actual hot dog is 6" long. Avast, me proud beauty! Blimey! Arrr! Blimey! It seems a little short, I wanted this rocket t' fly stable. Begad! Blimey! T' "Dog's" body tube length is 9". Blimey! Blimey! Avast, me proud beauty! Blimey! T' "Dog's" overall length with nose cone and motor mount (extension) in place was now 10 1/4".

After fillin' t' nose cone, arrr, me bucko, matey, I used t' back o' a razor blade t' press in wrinkle lines like those on a hot dog end. Aye aye! T' wrinkles radiate out from t' center o' t' nose cone tip.

I am tryin' t' capture t' look o' foot-long hotdog with it's ends stickin' out o' t' bun. I cut t' "bun" tube length at 5 ½". Aye aye! With t' two split nose cones in place, me bucko, t' overall "bun" length is 8 5/8".

It'd be easier t' fill t' tube spirals and balsa grain before cuttin' t' bun tube in half and splittin' t' bun nose cones.

(Scratch) Hot Dog(Scratch) Hot Dog

(Scratch) Hot Dog I marked t' Bun body tube down its entire length and extended t' line up t' two end nose cones. Avast! I extended t' pencil lines over t' top o' t' cones, completely around under t' shoulder. Ya scallywag! T' make a clean split, I used a straight edge razor blade t' cut 1/4" into t' cone. This should insure a clean outside edge. Begad! Arrr! I switched over t' a #11 X-Acto after t' razor blade t' deepen t' cut. Ya scallywag! I broke apart t' cones. I be happy with t' results. Avast! T' edges were clean and t' inside "flat" areas o' t' cones would only require some Fill 'n' Finish t' smooth them out.

I sanded square t' (rounded) nose cone shoulder ends. Begad! I left ½" o' t' shoulder. Avast, me proud beauty! I'll make two flat inside wall pieces, me hearties, glued inside and flush with t' body tube walls and nose cone ends.

After fillin' t' seams, me bucko, matey, I only cut through one side o' t' bun body tube. Avast, me proud beauty! Ya scallywag! T' opposite side was scored with a straight edge and (dull) butter knife only creasin' t' line. This let t' tube open like an real hot dog bun.

T' engine mount was taken from Semroc Squire kit. Ya scallywag! Keelhaul®©™ cord be tied t' t' engine hook. Avast, me proud beauty! Ahoy! A 3/16" X 18" elastic shock cord is tied t' t' Keelhaul®©™. I picked a 12" red and yellow Semroc chute t' match t' Mustard and Ketchup condiment motif.

With both bun nose cones in place thar be a rectangular open area inside. I cut 1/16" balsa "planks" t' fit t' void. I cut them a little oversize and sanded them t' fit. T' final size was 2" wide x 4 7/16" long. Well, blow me down! It would be difficult t' fill and sand t' interior balsa so it covered them with paper.

This is where it got interesting. I needed fins that would fit t' hot dog theme. Avast, me proud beauty! I thought o' plastic knife, fork and spoons for fins, matey, but another entry had already incorporated sporks into their design. Begad! My youngest daughter suggested ketchup, arrr, mustard, and relish packets should be used somewhere in t' design. Begad! Why nay t' fins? We picked some packets up at a local fast grub restaurant. I cut off t' back o' t' packets, emptied, then washed and dried t' plastic sleeves. Begad! T' empty packets were contact cemented onto 1/16" balsa. Aye aye! Avast! Simple, fast, and in t' theme o' t' model.

Slots were cut into t' bun's tail end and t' fins were pressed into place. Super glue fillets followed. T' Bun shape didn't allow for 120 degree spacin' o' t' fins. Begad! Ya scallywag! Blimey! While they aren't symmetrical, me hearties, they are on straight. Well, blow me down! Avast! Blimey! I made sure t' fins trailed away from t' rocket body, once again t' improve stability.

I glued a 1 ½" long launch lug t' t' backside o' t' hot dog body. Blimey! T' lug was centered out o' sight, inside t' bun. Ya scallywag! Avast! T' hot dog was set in t' bun and a line o' super glue be run down t' seams.

T' Keelhaul®©™ line was pulled through t' front o' t' dog tube and tied on a 3/16" x 18" elastic cord.

I found t' biggest, heavy screw eye I had. Ya scallywag! Any additional nose weight could help this model fly straight. Ya scallywag! I attached t' shock cord and parachute snap swivel t' t' screw eye.

Finishing:
When buyin' spray paint at WalMart, me bucko, shiver me timbers, me bucko, I walked through t' paint department with real hot dogs and buns in hand. Avast, me proud beauty! I wanted match t' colors as closely as possible. Blimey! Well, blow me down! T' Bun is actually two different colors. T' inside o' t' bun is much lighter than t' outside. I sprayed two coats o' grey primer, sandin' betwixt coats. T' inside o' t' bun be sprayed with Wal-Mart Almond. Avast, me proud beauty! Well, blow me down! I set t' bun face down (on t' open wedge cut) then sprayed t' outside with Wal-Mart Red Primer. Begad! No masking, arrr, me bucko, I wanted t' colors t' blend at t' "buns" cut line.

To replicate t' lighter color o' t' bun at t' wedge cut (through t' body), I sprayed more Almond color on a kitchen sponge. Avast, me proud beauty! I dabbed some o' t' Almond paint onto t' bun opening. Avast, me proud beauty! This gave it t' same rough color separation like on a real hot dog bun.

 

Flight:
T' Orlando NARRRRR section, arrr, shiver me timbers, R.O.C.K., me bucko, had a scheduled launch on July 10. In addition t' t' regular members, thar was t' be a school group thar with many first time fliers. Avast, me proud beauty! Avast! Many o' t' kids hadn't seen an odd-roc before, me bucko, and one even asked if I had another hot dog he could have for lunch. Avast, me proud beauty! I prepped t' (S)Hot Dog with a C6-3 with standard Estes wadding. Ya scallywag! Motor retention was an Estes style metal hook. Begad! I usually have great confidence in me rockets as I usually build proven designs, however, ya bilge rat, I was a little nervous as t' RSO called for a heads up.

T' first flight was vertical but t' model made a 10 foot spiral goin' up. Ahoy! I wanted better stability and needed more nose weight. Recovery be nominal with no damage. T' length o' t' Keelhaul®©™/elastic combination worked well. Blimey! There was no zipperin' or nose cone dents. Avast! Blimey! Now, me bucko, shiver me timbers, ya bilge rat, for t' nose weight.

Bob, a fellow R.O.C.K. member, arrr, offered up a quick link. I attached it t' t' large screw eye. As well, another R.O.C.K. Begad! member had some modelin' clay. I rolled two thin "worms" o' clay and pressed them into t' hot dog/bun seam. Aye aye! I prepped again usin' another C6-3.

This time it was a slow, straight, vertical boost t' a altitude o' approximately 225 feet. Arrr! Well, blow me down! Deployment be at apogee. Ya scallywag! Avast! There be no damage, me hearties, burning, or charrin' on recovery. Begad! Begad! T' model is now retired.

(Scratch) Hot Dog(Scratch) Hot Dog

 

Summary:
This was a great experience. It was fun t' construct a different scratch build again. Arrr! T' kids (first timers) at t' launch got quite a kick out o' t' design.

PROs: T' reactions o' t' first time fliers at t' local launch. Avast, me proud beauty! I found a few new techniques: "press mounting" fins in slots cut into t' balsa "bun" ends. When t' fins were in place, I simply ran super glue fillets. Begad! T' joints were very strong. Lastly, matey, arrr, pressin' "wrinkles" into a finished nose cone end usin' t' backside o' a single edge razor blade gave t' hot dog a certain realism.

CONs: Just tough t' fill balsa and body tube seams. Arrr! I had three different fillin' sessions. T' nose cone and body tube splits were t' most difficult part o' construction. I had t' fill t' spirals before cuttin' and splittin' and then fill again after gluin' t' bun nose cones into t' body tubes. Avast, me proud beauty! This project had a few o' those "Wakin' up in t' middle o' t' night" moments when realizin' different construction and material techniques.

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