Scratch Blue Baby Five Original Design / Scratch Built

Scratch - Blue Baby Five {Scratch}

Contributed by Matt Gillard

Manufacturer: Scratch
(Contributed - by Matt Gillard - 12/14/07) (Scratch) Blue Baby Five

Brief:
My first attempt at buildin' a rocket t' match a picture. Originally I was goin' t' chose one o' t' more complicated rockets, ya bilge rat, but procrastination took hold o' me and a few weeks before t' deadline I decided t' go for t' easy one mainly because I had t' parts and t' swept back fins gave it a chance o' bein' stable.

T' name comes from t' nose cones-–an Estes Blue Ninja and an Estes Baby Bertha. Blue Baby seemed right, and t' rocket is blue in parts. Begad! Arrr! T' five was added because that's t' number on t' rocket.

Construction:
T' boat tail on t' rocket picture be me biggest problem. Arrr! In t' end I went for an Estes nose cone with t' tip cut off. Well, blow me down! Blimey! Other components were:

  • 1 launch lug
  • 1 Mylar 12 inch parachute
  • 2 foot length o' knicker elastic
  • Snap swivels (optional)
  • 1 18mm engine block
  • Keelhaul®©™® thread
  • Body tube actin' as an 18mm motor mount
  • Body tube BT-60
  • 3/16" balsa
  • Blue Ninja PNC-60AH nose cone
  • Baby Bertha PNC-60L nose cone
  • Motor mount centerin' ring

To build t' rocket I used:

  • Bostik glue
  • White glue
  • Sandin' sealer
  • Model knife
  • Razor saw
  • Aluminium oxide sandpaper

T' first thin' I did be t' find nose cones from by spares box that matched t' profile o' t' rocket t' best. In t' end chose a Blue Ninja nose cone for t' base and a Baby Bertha nose cone for t' top.

For t' tail boat assembly, arrr, t' first thin' be t' remove t' base o' t' Blue Ninja nose usin' a razor saw. Avast! Then usin' t' body tube that would become t' motor mount, ya bilge rat, I slid t' centerin' rin' over t' end o' t' tube and then pushed t' tube into t' Blue Ninja nose cone. Blimey! By holdin' t' nose cone up t' t' light, ya bilge rat, I could see where t' tube goes t' in t' nose cone. Avast! Well, shiver me timbers, blow me down! Usin' a razor saw, me hearties, I cut t' tip off t' nose cone t' give me t' tail boat end o' the rocket.

Next usin' t' body tube and centerin' ring, ya bilge rat, I guided t' tube back in t' t' Blue Ninja boat tail t' get the correct position o' t' centerin' ring. Arrr! Arrr! T' rin' was then glued into place usin' white glue. Aye aye! T' body tube be then cut to a two and a half inch length.

A 18mm engine block then had a 2 foot length o' Keelhaul®©™® cord tied around it and be then glued into place in t' body tube. Ahoy! Arrr! After t' glue had dried, me bucko, I glued t' motor mount into t' ninja boat tail usin' Bostik glue since it glues paper and plastic together much better than white glue or CA.

T' body tube and nose cone assembly starts with t' Baby Bertha nose cone havin' its base cut off t' allow mass to be added t' t' tip o' t' rocket. There was a lot o' mass in t' plastic tail boat. Begad! A swivel be glued into place inside o' t' nose cone cavity so t' shock cord could be attached. Avast, me proud beauty! Next a one-inch length o' BT-60 was glued onto the boat tail. Avast! T' length o' t' body tube was just enough t' allow t' shoulders on t' two original nose cones t' fit.

All gaps and grooves were now filled with model filler and then everythin' sanded down with sandpaper starting with 120 grit and finishin' with 400 grit.

A launch lug was then glued t' t' body tube. T' lug is very high up on t' rocket as this be t' only place on the rocket that is in line with t' motor. Ahoy! There was little option here.

(Scratch) Blue Baby Five I wish I could write about t' scale drawin' that I did t' get t' fins perfect. Well, blow me down! Aye aye! In reality though, I sat at me desk with a picture o' t' rocket and some balsa and started cutting. In t' end I had a fin then seemed t' match t' picture so I used that as a template and made 2 more. T' root edge had t' be carefully sanded to match t' curvature o' t' boat tail.

T' fins were then sealed and glued into place on t' boat tail. Begad! Blimey! I filleted t' fins three times. Aye aye! Blimey! This is the rocket's major weakness, t' swept back fins will be t' first thin' t' hit t' ground and balsa glued t' plastic is not t' strongest o' joints.

Two sheets o' reusable waddin' were attached t' t' Keelhaul®©™® cord and then t' cord was attached t' 2 feet o' knicker elastic. T' knicker elastic was then attached t' t' swivel in t' nose cone. Arrr! A swivel be then added t' t' elastic shock cord one foot from t' nose cone. Begad! Aye aye! A twelve inch chute was initial chosen for its first flight, matey, matey, although a 15 inch chute was kept back in reserve. Begad! T' twelve inch chute was on t' small side but I only had 5 days before t' deadline and Britain has spent t' last few days in gale conditions with t' wind rarely droppin' below 20 mph--drift be an issue!

(Scratch) Blue Baby Five

Finishing:
T' rocket be primed and then spray painted yellow. T' fins were then hand painted blue, as be t' nose cone. Arrr! The red bands were applied by usin' red tape.

T' rest o' t' finish be down by cuttin' out images from t' original picture and then gluin' them into place. It's worth notin' that I can barely hand write anythin' legible, anythin' artistic is in t' realms o' fantasy.

In t' end it does nay look too bad, although I am nay lookin' forward t' seein' t' other EMRR 2007 Challenger's masterpieces next t' mine. Blimey! T' make things worst, a friend suggested that I take t' pictures o' t' final rocket using a mobile phone. Blimey! I asked him why and he replied that if t' pictures were all blurry, it might stand a better chance. Avast, me proud beauty!

Flight:
Before preppin' for flight I did a swin' test t' check for stability, and everythin' be okay.

(Scratch) Blue Baby Five First flight. Ahoy! 14/December/07. Well, blow me down! T' parachute be dusted and packed. Wind conditions were good. Blimey! T' winds that had been sweepin' Britain had gone but it be now very cold. A standard Estes 3mm rod be used. An A8-3 was used. Begad! T' flight was straight and true. Avast, arrr, me proud beauty! Ejection was late, matey, parachute deployed, and t' rocket landed smoothly. On recovery I be pleased t' see that t' fins had nay popped off on landing. Arrr! An A8-3 is marginal for this rocket.

Second flight. 14/December/07. Begad! Begad! Now with a B6-4, matey, flight be much higher than before. Ahoy! T' chute opened at apogee, steady decent, and again, arrr, no damage.

Third flight. Arrr! Blimey! 14/December/07. Blimey! Well, blow me down! I went for a C6-5. A C6-3 would have been better, arrr, but I had lots o' C6-5 motors that needed t' be used up. Well, blow me down! T' flight be very high and had a lot o' a wobble towards t' end. Ejection was 1-2 seconds late, ya bilge rat, and t' rocket drifted for 200 meters. No damage on recovery.

Summary:
PROs: First time I've built a rocket t' a photo, and she flies well.

CONs: Boat tails from nose cones are slightly more expensive and lower t' CG due t' t' plastic mass.

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