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. Ya scallywag! Avast! Originally I was goin' t' chose one o' t' more complicated rockets, ya bilge rat, matey, 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. Avast! Blimey! Blue Baby seemed right, and t' rocket is blue in parts. Avast, me proud beauty! T' five was added because that's t' number on t' rocket.

Construction:
T' boat tail on t' rocket picture was me biggest problem. Begad! In t' end I went for an Estes nose cone with t' tip cut off. Avast! 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 was 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, matey, ya bilge rat, t' first thin' was t' remove t' base o' t' Blue Ninja nose usin' a razor saw. Begad! Blimey! Then usin' t' body tube that would become t' motor mount, I slid t' centerin' rin' over t' end o' t' tube and then pushed t' tube into t' Blue Ninja nose cone. Aye aye! By holdin' t' nose cone up t' t' light, I could see where t' tube goes t' in t' nose cone. Blimey! Usin' a razor saw, matey, 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, I guided t' tube back in t' t' Blue Ninja boat tail t' get the correct position o' t' centerin' ring. Avast! Avast, ya bilge rat, me proud beauty! T' rin' was then glued into place usin' white glue. Avast, ya bilge rat, me proud beauty! T' body tube was 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 was then glued into place in t' body tube. Avast, me proud beauty! After t' glue had dried, arrr, 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 be a lot o' mass in t' plastic tail boat. A swivel be glued into place inside o' t' nose cone cavity so t' shock cord could be attached. Avast! Next a one-inch length o' BT-60 be glued onto the boat tail. T' length o' t' body tube be 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. Arrr! 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. Well, blow me down! There be little option here.

(Scratch) Blue Baby Five I wish I could write about t' scale drawin' that I did t' get t' fins perfect. Ya scallywag! Avast, ya bilge rat, me proud beauty! In reality though, arrr, I sat at me desk with a picture o' t' rocket and some balsa and started cutting. Arrr! In t' end I had a fin then seemed t' match t' picture so I used that as a template and made 2 more. Ya scallywag! 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. Ya scallywag! Begad! I filleted t' fins three times. 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 be attached t' 2 feet o' knicker elastic. Begad! T' knicker elastic was then attached t' t' swivel in t' nose cone. Ya scallywag! A swivel was then added t' t' elastic shock cord one foot from t' nose cone. A twelve inch chute was initial chosen for its first flight, arrr, although a 15 inch chute be kept back in reserve. Aye aye! 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. Ahoy! T' fins were then hand painted blue, as was t' nose cone. Avast! The red bands were applied by usin' red tape.

T' rest o' t' finish was 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. Ahoy! T' make things worst, a friend suggested that I take t' pictures o' t' final rocket using a mobile phone. Arrr! Blimey! I asked him why and he replied that if t' pictures were all blurry, me bucko, it might stand a better chance. Begad! Blimey!

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

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

Second flight. 14/December/07. Aye aye! Now with a B6-4, shiver me timbers, me bucko, flight be much higher than before. Avast, me proud beauty! T' chute opened at apogee, steady decent, and again, matey, me hearties, no damage.

Third flight. Begad! Blimey! 14/December/07. I went for a C6-5. Avast, me proud beauty! Blimey! A C6-3 would have been better, but I had lots o' C6-5 motors that needed t' be used up. Blimey! Blimey! T' flight be very high and had a lot o' a wobble towards t' end. Begad! Blimey! Ahoy! Blimey! Ejection was 1-2 seconds late, and t' rocket drifted for 200 meters. Begad! Blimey! 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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