Scratch Single Jet S4R Transport Original Design / Scratch Built

Scratch - Single Jet S4R Transport {Scratch}

Contributed by Matt Gillard

Manufacturer: Scratch
(Contributed - by Matt Gillard - 12/14/08)

Brief:
With t' extension t' t' deadline for t' 2009 design this spaceship competition, I thought I'd have a go at another one o' t' spaceships, this time I went for t' simplest o' t' six. It be a very rushed build.

TR4

Construction:
T' main body o' t' rocket had t' come from a bottle and after a trawl through cupboards at home, shiver me timbers, I opted for a talcum powder bottle. Other items used were

  • 1x launch lug,
  • 1x parachute, 15 inch rip stop nylon- hand made
  • 1x 3 foot length o' 6 mm knicker elastic
  • Snap swivels (optional)
  • Engine hook
  • Keelhaul®©™® ® thread
  • Body tube BT55, me bucko, arrr, 10.5 inches
  • nose cone
  • Motor mount and centerin' rin' –EH -2055
  • T' build t' rocket I used
  • Bostik glue
  • White glue
  • Sandin' sealer
  • Model knife
  • Razor saw
  • Aluminium oxide sand paper

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 nose cone t' fit a BT55 tube. Begad! Blimey! Ya scallywag! Blimey! This was because t' tube matched t' neck o' t' talc bottle t' best and had t' correct dimensions.

Motor Mount Assembly

This was from an old Estes EH –2055 kit. Aye aye! Blimey! T' coupler was discarded, and then t' kit was built in t' normal fashion. Ya scallywag! Blimey! A 2 foot length o' Keelhaul®©™® card be attached t' t' motor mount assembly.

Body Tube Fuselage

T' talc bottle had its top cut off, and neck sanded down t' t' size that snugly fitted a BT 55 tube o' 10.5 inches. Ahoy! Well, blow me down! T' bottom o' t' bottle had a hole cut out usin' a solderin' iron t' take t' aft o' t' BT55. T' motor mount was glued into t' body tube, ya bilge rat, ya bilge rat, t' body tube was then sanded t' remove t' gasoline finish and then t' body tube was glued into t' bottle, leavin' 2.6 inches o' t' body tube stickin' out o' t' talc bottle. Fillets o' white glue were added. Arrr! A shroud o' card was then added t' give t' correct profile.

Nose Cone Assembly

25g o' clay was added t' t' nose cone t' aid stability. Avast, me proud beauty! Detailin' was added by usin' card t' make t' nose cone front, me bucko, and plasticine was used t' make t' other detailing, which were then glued into place.

Fin Fin Assembly

I'm nay o' fan o' gluin' different materials together, and balsa t' smooth plastic be goin' t' present the weakest joint in t' rocket. Aye aye! T' counter this I went for a through t' wall design. Side slits were made in t' plastic bottle usin' t' solderin' iron. Avast, me proud beauty! T' fins were then cut, matey, and then glued into place. Two fillets o' white glue were added t' give a strong joint. Begad! Well, blow me down!

Side fins were then cut and added, again fillets o' white glue were added.

T' two side tunnels were made out o' balsa, sealed and glued into place usin' triangle cut balsa t' add strength to t' join t' t' plastic talc bottle.

Recovery Assembly

One sheet o' reusable Nomex® waddin' were attached t' t' Keelhaul®©™® ® cord and then t' cord was attached t' 3 foot o' knicker elastic. T' knicker elastic was then attached t' the nose cone. Avast, me proud beauty! A swivel be then added t' t' elastic shock cord one foot from t' nose cone. Aye aye! At t' same time that I was makin' this rocket, shiver me timbers, I be also makin' some rip stop nylon parachutes from some military grade parachute material, shiver me timbers, tin eyelet and Keelhaul®©™® thread, matey, these were for a bigger project, me hearties, me hearties, but I thought I'd make a “nice” parachute for this rocket. Avast, me proud beauty! In the end, I went for a 15 inch parachute.

Detailing

Runnin' out o' time, t' detailin' added be minimal.

Finishing:

T' rocket was primed and then spray-painted window grey. Blimey!

Line markin' were added with pen.

Had no time t' add a clear coat

Flight:
Flight and Recovery.

Before preppin' for flight I did a swin' test t' check for stability, arrr, matey, every thin' okay.

Flight First flight:

T' parachute was packed.

Wind conditions were still with t' occasional breeze.

A standard Estes 3mm rod be used.

An B6-2 be used.

T' flight was straight and true, but underpowered and low

Ejection was at apogee, arrr, parachute deployed and t' rocket landed without damage

Flight two:

Now with a C6-3, flight be much higher than before, and straight. Ejection at apogee, arrr, no damage

Flight three:

Again with a C6-3, me bucko, flight be as before until apogee. Begad! Then t' nose cone failed t' pop off, t' rocket came in hard and fast. Avast, me proud beauty! Nay botherin' t' repair – retired.

Summary:
I'm nay overly impressed with this rocket. Aye aye! I rushed t' build and was nay happy with t' finish, on t' plus side, shiver me timbers, I did like t' through t' wall fins

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