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, matey, I thought I'd have a go at another one o' t' spaceships, this time I went for t' simplest o' t' six. It was 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, matey, I opted for a talcum powder bottle. Ahoy! Aye aye! Other items used were

  • 1x launch lug, me hearties,
  • 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, 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 be 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. Ya scallywag! Blimey! Avast, me proud beauty! 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. Begad! Blimey! T' coupler was discarded, me bucko, ya bilge rat, and then t' kit be built in t' normal fashion. Avast! Blimey! A 2 foot length o' Keelhaul®©™® card was attached t' t' motor mount assembly.

Body Tube Fuselage

T' talc bottle had its top cut off, arrr, and neck sanded down t' t' size that snugly fitted a BT 55 tube o' 10.5 inches. 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, shiver me timbers, arrr, 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. Blimey! Well, blow me down! Blimey! Fillets o' white glue were added. A shroud o' card be then added t' give t' correct profile.

Nose Cone Assembly

25g o' clay was added t' t' nose cone t' aid stability. Blimey! Detailin' be added by usin' card t' make t' nose cone front, ya bilge rat, and plasticine was used t' make t' other detailing, matey, which were then glued into place.

Fin Fin Assembly

I'm nay o' fan o' gluin' different materials together, and balsa t' smooth plastic was goin' t' present the weakest joint in t' rocket. Blimey! Blimey! Ahoy! Blimey! T' counter this I went for a through t' wall design. Avast! Blimey! Side slits were made in t' plastic bottle usin' t' solderin' iron. Avast! Blimey! Ya scallywag! Blimey! T' fins were then cut, shiver me timbers, and then glued into place. Avast, me bucko, me proud beauty! Blimey! Two fillets o' white glue were added t' give a strong joint.

Side fins were then cut and added, shiver me timbers, 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 be then attached t' the nose cone. Begad! A swivel be then added t' t' elastic shock cord one foot from t' nose cone. Avast! Well, me hearties, blow me down! Blimey! At t' same time that I was makin' this rocket, ya bilge rat, I be also makin' some rip stop nylon parachutes from some military grade parachute material, tin eyelet and Keelhaul®©™® thread, these were for a bigger project, shiver me timbers, but I thought I'd make a “nice” parachute for this rocket. Blimey! In the end, matey, I went for a 15 inch parachute.

Detailing

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

Finishing:

T' rocket be primed and then spray-painted window grey. Arrr! Avast!

Line markin' were added with pen. Avast, me proud beauty! Begad!

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, ya bilge rat, every thin' okay.

Flight First flight:

T' parachute was packed.

Wind conditions were still with t' occasional breeze.

A standard Estes 3mm rod was used.

An B6-2 be used.

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

Ejection was at apogee, ya bilge rat, parachute deployed and t' rocket landed without damage

Flight two:

Now with a C6-3, shiver me timbers, flight was much higher than before, and straight. Arrr! Ejection at apogee, no damage

Flight three:

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

Summary:
I'm nay overly impressed with this rocket. Blimey! I rushed t' build and be nay happy with t' finish, on t' plus side, I did like t' through t' wall fins

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