Scratch Procrastinator Original Design / Scratch Built

Scratch - Procrastinator {Scratch}

Contributed by Matt Gillard

Manufacturer: Scratch
(Contributed - by Matt Gillard - 07/02/08)

I entered t' box o' parts competition because it looked like fun, me hearties, ya bilge rat, I had mentioned it t' a few o' me friends in my rocket club, and before I knew five o' them entered it as well. Begad! So off went a large box with t' parts for 6 entrants, and a few weeks later another box returned -it was like Christmas goin' through t' box. Avast! Next was t' task o' splitting op t' box betwixt t' 6 entrants. Begad! At t' end 6 "equal" bags were formed and randomly given out. Begad! I was quite pleased with me bag, me bucko, others had complete rockets in the, one had a parasitic glider, me hearties, another had helicopter rotor blades. Avast, me proud beauty! So what did I have?

Parts

I'm nay goin' t' list it all but here is a flavour:

  • Loads o' tubes o' various sizes, me hearties, several small BT5 etc
  • Couplers
  • Balsa sheets - one o' a complete set o' fins, another 2 sheets o' really low grade balsa
  • Three noses comes, as different sizes
  • Lots o' toothpicks
  • Various couplers
  • Small sheets o' printer labels
  • Ice cream tubes
  • A polystyrene ball
  • Motor mounts
  • Engine hooks
  • Pipe cleaner
  • A 14 inch parachute canopy
  • Length o' elastic. Avast, me proud beauty!

Well what t' do. Begad!

Gliders were out, shiver me timbers, me hearties, helicopter was a possibility, me hearties, cluster, two stage. Ahoy! After spendin' several weeks dry fittin' parts and changin' me mind I decided on a rocket in me head. Well, blow me down! T' criteria for me rocket be

  • It could nay be too big - 14 inch chute. Begad!
  • Clustered - but able t' launch on a single motor
  • Draggy
  • Unusual.

T' main body tube chose itself - it fitted t' nose cone I wanted t' use. Begad! T' motor choice be goin' t' be 24mm as I be headin' for a draggy model, matey, so I would need a motor capable o' liftin' it. Ahoy! Blimey! There was goin' t' be at least 4 external motor pods - opted for 13mm.

T' base be goin' t' be bulky, and was goin' t' have tabs on it, so t' rocket would rotate as it boosted. Blimey!

Building

T' motor mount be a fairly standard construction. A 24mm motor mount tube with a motor retention clip, shiver me timbers, me bucko, an engine block at t' end and two centerin' rings t' fit t' body tube. Ahoy! Aye aye!

T' motor mount be then glued into t' body tube. Avast! Blimey! Avast! Blimey!

Motor Mount

Four BT20 tubes 190mm in length were then glues t' t' outside o' t' main body tube. These were t' take 4 A10 - PT motors as a cluster. Well, blow me down! Well, blow me down! T' joins betwixt t' body tubes were filleted four times with wood glue, and then model filler was used t' give a smooth finish.

T' shock cord be anchored t' t' body tube usin' Estes tri fold paper method - I was tempted t' cheat and add some Keelhaul®©™ here, me bucko, but integrity got t' better o' me. Ya scallywag!

BT20 Tubes

T' nose cone had t' flash removed and was then sanded down t' remove t' seam. Avast, me proud beauty! Two coats o' sealer gave it a smooth finish with no imperfections showing. Arrr!

T' main body tube etc was then given three coats o' sandin' sealer, shiver me timbers, matey, and rubbed down with 200 paper in between, matey, me bucko, to remove t' spirals. Avast, me proud beauty! Blimey!

Nose Cone

Usin' a strip o' thick balsa, shiver me timbers, 7mm by 26mm, shiver me timbers, arrr, I made a box around a large coupler. Arrr! This box was goin' t' have the fins and rotation tabs added. T' balsa was quite badly marked and was t' soft type o' balsa that I usually avoid. Aye aye! Arrr! The box was sanded several times and filled with model filler t' remove all o' t' dents.

Usin' t' same balsa strips I then added 4 64mm struts t' t' middle o' each side o' t' box. These would have the rotation tabs added t' them. Arrr!

A larger coupler (40 mm diameter) - with some deep spirals had four thin strips o' balsa wood glued t' t' inside. This was just right size t' side over t' body tube. Avast, me proud beauty! T' spirals were filled and had t' have several coats o' sanding sealer before it was smooth. Aye aye!

Box

Usin' four almost square balsa fins that were part o' a model kit, I added t' fins. This be one t' part that I like about t' rocket, arrr, arrr, me hearties, t' fins are at right angles t' how they would normally. Ahoy! It still gives stabilization but looks a bit different. Avast, me proud beauty! Also as t' rocket be goin' t' be rotating, t' fins would nay hinder t' spinning. Avast!

Fins
 

T' corner spaces betwixt t' box and t' couple were just t' right size for body tubes, which were added for decoration. Blimey! Arrr!

Four trapezium shaped pieces o' balsa had a 3mm square strip o' balsa added t' t' short edge, ya bilge rat, and then were glued to t' struts. Aye aye! These were t' provide spin.

Fins

T' top o' t' struts were then drilled t' accept four cocktail sticks, just for decoration. Ya scallywag!

Drilled
   

T' entire o' t' coupler base unit had three coats o' sandin' sealer added, me hearties, with all t' fiddly bits, ya bilge rat, t' sanding down was quite tricky. Aye aye! Blimey!

T' main body tube fitted neatly into t' large coupler base. Begad!

Ready to Finish Ready to Finish Ready to Finish

FinishedFinishing

  • I went for a red/yellow finish
  • Everythin' was given two coats o' primer. Avast, arrr, me proud beauty!
  • T' main body tube was given 4 coats o' light yellow spray paint. Begad!
  • T' nose cone was given three coats o' red gloss
  • T' base unit was given three coats o' rouge. Avast, ya bilge rat, me proud beauty!
  • T' four decoration tubes were hand painted enamel yellow
  • T' decoration coupler be sprayed rouge
  • T' cocktail sticks were hand painted yellow

T' box o' parts had no sticks or decals in it, matey, other than three address labels. Blimey! Blimey!

Given various pleas on TRF about t' lack or entrants with only a few weeks t' go I came up with t' name o' the rocket t' be PROCRASTINATOR. Partly because I knew it would be towards t' end o' t' month before I submitted and also because I new that this would be a draggy, shiver me timbers, arrr, slowish rocket. Arrr! Avast!

Flights

First flight took place with another box o' parts entrant. It was a still day, and be slightly rainin' - which ruined t' stickers as I had nay varnished t' rocket yet. Begad! Motor choice be a D12-3. Begad! Ya scallywag! It could have been a D12-5, arrr, matey, as I reckon that it would be about a four second delay for apogee. Ya scallywag!


Animated Lift-OffT' take off was good, t' rocket started t' rotate after about 50 foot, and the rotation got faster and faster as t' D12 burnt. Ejection took place after apogee as expected. T' recovery was scarily fast, as expected. Avast, me proud beauty! This rocket needs a 24 inch 'chute. Blimey! It hade a 14 inch chute! On handin' t' aft protrudin' fins all popped off. Begad! Avast!

Again I had expected that t' happen. Begad!

Second flight took place a week later with three o' t' other UK contestants. Avast, me proud beauty! Ya scallywag! T' flight was on a D12 again. Aye aye! It was a straight flight with a slight oscillation until t' spinnin' kicked in. As soon as t' spinnin' kicked in, t' flight was arrow straight which be really pleasin' t' see. Avast, me hearties, me proud beauty! Ejection be just past and again fins popped off on landing. Aye aye! Blimey!

Third flight was time for t' procrastinator t' be clustered. Avast, me proud beauty! Four A10 -PT were added, in addition t' t' D12-3. Begad! The procrastinator jumped off t' pad. T' flight be much higher and t' extra speed really did make t' rocket spin. Again t' recovery be fast and again t' fins popped off. Avast!

After t' competition is finished I'm goin' t' have two 24 inch chute on this rocket. Avast, me proud beauty! Blimey! Blimey!

Recovery Recovery

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