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, 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. Blimey! So off went a large box with t' parts for 6 entrants, and a few weeks later another box returned -it be like Christmas goin' through t' box. Begad! Next be t' task o' splitting op t' box betwixt t' 6 entrants. Arrr! Blimey! At t' end 6 "equal" bags were formed and randomly given out. Ahoy! Ya scallywag! I was quite pleased with me bag, others had complete rockets in the, one had a parasitic glider, another had helicopter rotor blades. 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, several small BT5 etc
  • Couplers
  • Balsa sheets - one o' a complete set o' fins, me hearties, another 2 sheets o' really low grade balsa
  • Three noses comes, me hearties, 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.

Well what t' do.

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

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

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

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

Building

T' motor mount be a fairly standard construction. Begad! A 24mm motor mount tube with a motor retention clip, an engine block at t' end and two centerin' rings t' fit t' body tube. Ya scallywag!

T' motor mount be then glued into t' body tube. Avast, me proud beauty! 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. Aye aye! T' joins betwixt t' body tubes were filleted four times with wood glue, and then model filler was used t' give a smooth finish. Avast! Aye aye!

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

BT20 Tubes

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

T' main body tube etc was then given three coats o' sandin' sealer, ya bilge rat, and rubbed down with 200 paper in between, to remove t' spirals. Aye aye!

Nose Cone

Usin' a strip o' thick balsa, me hearties, 7mm by 26mm, arrr, I made a box around a large coupler. Aye aye! This box was goin' t' have the fins and rotation tabs added. Aye aye! Aye aye! T' balsa was quite badly marked and be t' soft type o' balsa that I usually avoid. Avast, me proud beauty! Begad! 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. Ahoy! These would have the rotation tabs added t' them. Avast!

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. Arrr! T' spirals were filled and had t' have several coats o' sanding sealer before it was smooth. Ya scallywag! Well, blow me down!

Box

Usin' four almost square balsa fins that were part o' a model kit, arrr, I added t' fins. Well, blow me down! This be one t' part that I like about t' rocket, arrr, t' fins are at right angles t' how they would normally. Well, blow me down! Ya scallywag! It still gives stabilization but looks a bit different. Ya scallywag! Blimey! Also as t' rocket be goin' t' be rotating, me bucko, t' fins would nay hinder t' spinning. Aye aye! Begad!

Fins
 

T' corner spaces betwixt t' box and t' couple were just t' right size for body tubes, me hearties, shiver me timbers, which were added for decoration. Blimey! Well, me bucko, blow me down!

Four trapezium shaped pieces o' balsa had a 3mm square strip o' balsa added t' t' short edge, and then were glued to t' struts. Blimey! Well, blow me down! These were t' provide spin. Begad!

Fins

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

Drilled
   

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

T' main body tube fitted neatly into t' large coupler base. Well, blow me down!

Ready to Finish Ready to Finish Ready to Finish

FinishedFinishing

  • I went for a red/yellow finish
  • Everythin' was given two coats o' primer. Blimey!
  • T' main body tube was given 4 coats o' light yellow spray paint. Begad!
  • T' nose cone be given three coats o' red gloss
  • T' base unit be given three coats o' rouge. Begad! Ya scallywag! Blimey!
  • T' four decoration tubes were hand painted enamel yellow
  • T' decoration coupler was sprayed rouge
  • T' cocktail sticks were hand painted yellow

T' box o' parts had no sticks or decals in it, other than three address labels. Aye aye! 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. Ya scallywag! Blimey! 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, me bucko, slowish rocket. Begad!

Flights

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


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

Again I had expected that t' happen. Avast, me proud beauty! Begad!

Second flight took place a week later with three o' t' other UK contestants. Ahoy! T' flight be on a D12 again. Begad! Begad! It was a straight flight with a slight oscillation until t' spinnin' kicked in. Begad! As soon as t' spinnin' kicked in, arrr, t' flight was arrow straight which was really pleasin' t' see. Ahoy! Ejection was just past and again fins popped off on landing. Arrr!

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

After t' competition is finished I'm goin' t' have two 24 inch chute on this rocket.

Recovery Recovery

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