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. I decided t' use t' "Centuri" ST style tubin' with thicker body tube walls. Ya scallywag! A parts list was made, then an order be placed (online) t' Semroc on June 13, 2008. Blimey! Well, shiver me timbers, blow me down! I received t' parts by mail on June 16, shiver me timbers, 2008. Blimey! Avast, me bucko, me proud beauty! Very fast delivery and great customer service, ya bilge rat, as usual.

Parts list: 

  • 2 "Bun" Nose Cones, arrr, ya bilge rat, BNC2025
  • 1 "Hot Dog" Nose Cone, ya bilge rat, arrr, shiver me timbers, BC-837 from Squire kit
  • "Hot Dog" Body Tube, ST890, shiver me timbers, 8 Series
  • "Bun" Body Tube, matey, matey, ST2060, 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. Aye aye! After seein' it "in t' bun" it looked too thin. Ya scallywag! I switched t' wider 8 series parts from a extra Semroc Squire kit I had. I also used t' Squire's engine mount, nose cone and Keelhaul®©™. Ya scallywag! All other parts were standard: 1/8" launch lug, a big screw eye, me bucko, ya bilge rat, matey, 3/16" x 18" elastic shock cord, ya bilge rat, ya bilge rat, and 12" parachute.

As I work away from home, me hearties, I didn't have much time t' build t' model for t' EMRR contest. Begad! Ya scallywag! 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 be 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. 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. Ya scallywag! Ahoy! It seems a little short, shiver me timbers, I wanted this rocket t' fly stable. T' "Dog's" body tube length is 9". T' "Dog's" overall length with nose cone and motor mount (extension) in place was now 10 1/4".

After fillin' t' nose cone, I used t' back o' a razor blade t' press in wrinkle lines like those on a hot dog end. Avast! 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". Ahoy! With t' two split nose cones in place, 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. I extended t' pencil lines over t' top o' t' cones, completely around under t' shoulder. Well, blow me down! Blimey! Aye aye! Blimey! Blimey! Blimey! T' make a clean split, arrr, matey, arrr, I used a straight edge razor blade t' cut 1/4" into t' cone. Ya scallywag! Blimey! This should insure a clean outside edge. I switched over t' a #11 X-Acto after t' razor blade t' deepen t' cut. Begad! Blimey! Ya scallywag! Blimey! Blimey! Blimey! I broke apart t' cones. Aye aye! Blimey! I was happy with t' results. Blimey! Blimey! Blimey! Blimey! 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. I left ½" o' t' shoulder. Arrr! I'll make two flat inside wall pieces, me hearties, me hearties, glued inside and flush with t' body tube walls and nose cone ends.

After fillin' t' seams, me bucko, I only cut through one side o' t' bun body tube. Aye aye! Begad! T' opposite side was scored with a straight edge and (dull) butter knife only creasin' t' line. Well, blow me down! This let t' tube open like an real hot dog bun.

T' engine mount was taken from Semroc Squire kit. Begad! Keelhaul®©™ cord was tied t' t' engine hook. Arrr! Aye aye! A 3/16" X 18" elastic shock cord is tied t' t' Keelhaul®©™. Blimey! Blimey! 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. Blimey! Blimey! I cut 1/16" balsa "planks" t' fit t' void. Well, blow me down! Blimey! Avast! Blimey! I cut them a little oversize and sanded them t' fit. T' final size was 2" wide x 4 7/16" long. Ya scallywag! Blimey! Ya scallywag! Blimey! 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. Aye aye! I thought o' plastic knife, ya bilge rat, me bucko, fork and spoons for fins, but another entry had already incorporated sporks into their design. My youngest daughter suggested ketchup, me bucko, mustard, matey, ya bilge rat, and relish packets should be used somewhere in t' design. Why nay t' fins? We picked some packets up at a local fast grub restaurant. Begad! I cut off t' back o' t' packets, me bucko, emptied, me hearties, then washed and dried t' plastic sleeves. Well, arrr, blow me down! T' empty packets were contact cemented onto 1/16" balsa. Avast, me proud beauty! Simple, me hearties, 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. Avast, me proud beauty! T' Bun shape didn't allow for 120 degree spacin' o' t' fins. Well, blow me down! Arrr! While they aren't symmetrical, they are on straight. Ya scallywag! I made sure t' fins trailed away from t' rocket body, arrr, once again t' improve stability.

I glued a 1 ½" long launch lug t' t' backside o' t' hot dog body. Well, blow me down! T' lug was centered out o' sight, inside t' bun. T' hot dog was set in t' bun and a line o' super glue was 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, ya bilge rat, heavy screw eye I had. Aye aye! Any additional nose weight could help this model fly straight. Ya scallywag! Ya scallywag! I attached t' shock cord and parachute snap swivel t' t' screw eye.

Finishing:
When buyin' spray paint at WalMart, I walked through t' paint department with real hot dogs and buns in hand. I wanted match t' colors as closely as possible. T' Bun is actually two different colors. T' inside o' t' bun is much lighter than t' outside. Ahoy! Arrr! I sprayed two coats o' grey primer, me hearties, sandin' betwixt coats. T' inside o' t' bun was sprayed with Wal-Mart Almond. Begad! I set t' bun face down (on t' open wedge cut) then sprayed t' outside with Wal-Mart Red Primer. Well, blow me down! No masking, matey, 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), ya bilge rat, I sprayed more Almond color on a kitchen sponge. Arrr! I dabbed some o' t' Almond paint onto t' bun opening. Arrr! Avast! This gave it t' same rough color separation like on a real hot dog bun.

 

Flight:
T' Orlando NARRRRR section, matey, R.O.C.K., had a scheduled launch on July 10. Arrr! Ya scallywag! In addition t' t' regular members, ya bilge rat, thar was t' be a school group thar with many first time fliers. Well, shiver me timbers, blow me down! Many o' t' kids hadn't seen an odd-roc before, ya bilge rat, ya bilge rat, me bucko, and one even asked if I had another hot dog he could have for lunch. Ya scallywag! Begad! I prepped t' (S)Hot Dog with a C6-3 with standard Estes wadding. Avast! Motor retention be an Estes style metal hook. Arrr! Aye aye! I usually have great confidence in me rockets as I usually build proven designs, however, 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. Avast! Aye aye! I wanted better stability and needed more nose weight. Avast! Recovery be nominal with no damage. Avast! Well, blow me down! T' length o' t' Keelhaul®©™/elastic combination worked well. Ya scallywag! There was no zipperin' or nose cone dents. Avast, me proud beauty! Now, for t' nose weight.

Bob, shiver me timbers, me bucko, a fellow R.O.C.K. Ya scallywag! member, offered up a quick link. Arrr! I attached it t' t' large screw eye. Avast! As well, another R.O.C.K. member had some modelin' clay. I rolled two thin "worms" o' clay and pressed them into t' hot dog/bun seam. Ahoy! I prepped again usin' another C6-3.

This time it was a slow, ya bilge rat, matey, straight, vertical boost t' a altitude o' approximately 225 feet. Deployment be at apogee. Avast, me proud beauty! There was no damage, burning, arrr, or charrin' on recovery. T' model is now retired.

(Scratch) Hot Dog(Scratch) Hot Dog

 

Summary:
This be a great experience. Begad! Avast, me proud beauty! It was fun t' construct a different scratch build again. 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. Arrr! Blimey! Well, blow me down! Blimey! I found a few new techniques: "press mounting" fins in slots cut into t' balsa "bun" ends. When t' fins were in place, arrr, matey, I simply ran super glue fillets. T' joints were very strong. Arrr! Blimey! Lastly, 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. Avast, me proud beauty! Ahoy! I had three different fillin' sessions. Begad! Aye aye! 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. Ahoy! 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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