Scratch Little Lil Original Design / Scratch Built

Scratch - Little Lil {Scratch}

Contributed by Matt Gillard

Manufacturer: Scratch
 (Scratch) Little Lil

Brief:
A short rocket with three clustered outboard motors, me bucko, I called her Little Lil because she is little and lilac in color. Ya scallywag! Aye aye! Blimey! Made for t' box o' parts 2009 competition, I sent myself t' followin' items as I didn't have a design in mind and just put some stuff in a box.

Construction:
T' parts list:

  • Balsa sheets:
    • 3/16", three sections
    • 1/8", arrr, two sections
    • ¼ two sections
  • Birch rod
  • Inch width 3/16th section (used)
  • Dowel rod (used)
  • Body tubes:
    • 6 inch, arrr, shiver me timbers, ST-20 (used)
    • 16 inch, me bucko, BT-20
    • 18 inch, BT-20
    • 18 inch, shiver me timbers, BT-5 (used)
  • Nose cones:
    • 1 t' fit ST-20
    • 4 t' fit BT-20
    • 4 t' fit BT-5 (3 used)
  • Parachutes:
    • 12 inch Estes (used)
    • 18 inch Estes
    • Cloth 12 inch
    • 3 foot square o' rip stop nylon (used)
  • Other items:
    • Engine blocks for BT-20 x 5
    • Centerin' rings ID 24mm x 3
    • Keelhaul®©™ thread (used)
    • Cotton thread
    • Elastic cord 1 reel (used)
    • Swivels x 3 (1 used)
    • Engine hooks x5 (1 used)
    • Launch lugs x 5 (1 used)
    • Screw eye x 5 (3 used)
    • Plastic counters
    • 4 sheets o' card (1 used)
    • Reel o' 1mm nylon cord (1 used)
    • Plastic disks x16
    • Plastic weigh boats x 16
    • Eyelets x 40 (6 used)
    • Box o' matches
On top o' these parts I got sent t' followin' items t' be used:
  • Prismatic covers
  • Rubber band
  • Pencil
  • Pen
  • Plastic Easter egg

After last year's box o' parts rocket, matey, shiver me timbers, which I was quite proud of, it rotated as it went up and was a cluster, arrr, arrr, but it had a bilge-suckin' habit o' breakin' every time it landed and was a tad fussy. So this year I thought I'd go for a pretty standard but very usable rocket.

Goin' through t' parts I opted for t' 6-inch ST-20 with t' balsa nose cone. Well, blow me down! This would give me a short squat rocket. Ya scallywag! I would have t' go for swept back fins so I opted for three usin' t' inch width 3/16" section o' balsa. Begad! Each fin had t' followin' dimensions: root edge 36mm, me hearties, matey, ya bilge rat, leadin' edge 33mm, matey, matey, dowel edge 60mm, and trailin' edge 62mm.

Usin' t' balsa dowel rod, arrr, I added a rod t' t' top o' each fin. Ya scallywag! Avast, me proud beauty! T' rod be 180mm long with a gap betwixt t' fin and rod where t' two meet t' body tube. Blimey! This gave t' rocket an Estes Alien space probe kind o' look.

T' motor mount much more difficult. Begad! Blimey! As I had no centerin' rings for t' body tube, I had t' make two from one o' t' balsa sheets usin' a Dremel. Aye aye! Blimey! They were nay perfect but they fit. Arrr! Blimey! I laminated each rin' with cardstock. I used an 18mm motor tube and glued in t' centerin' rings then attached a length o' Keelhaul®©™ cord for t' shock cord anchor. T' motor mount was then glued into t' body tube and then filleted with white glue.

  

For somethin' a bit different, I decided t' add three outboard motors t' t' top o' t' body tube. Begad! Usin' 44mm lengths o' BT-5 I glued in a BT-5 balsa nose cone, matey, then off set t' outboard motors usin' t' same balsa strip used for t' fins. Avast! Avast, matey, me proud beauty! Dimensions for t' body tube lengths were 33mm, shiver me timbers, me hearties, leadin' and trailin' edges 21mm. T' outboards were then neatened up usin' car body filler t' smooth t' transition betwixt body tube, nosecone, me hearties, matey, and standoff. Aye aye! Well, blow me down! With these outboards bein' high up on t' body tube I be concerned that t' CP had been lifted. A launch lug was then glued t' t' side.

  

I then drilled out t' nosecone and filled t' cavity with lead t' raise t' CG t' make t' rocket more stable. Aye aye! Blimey! I screwed in three screw deadlights into t' base o' t' nose cone. Blimey! Blimey! T' nose cone be then added t' a 6-foot length o' shock cord.

To use one o' t' surprise items, a pencil, I sanded a pencil in half lengthwise and then cut t' pencil into three-inch long lengths. Begad! Avast, me proud beauty! These lengths were then added t' t' base o' t' body tube in line with t' outboards as decoration. Ya scallywag! Two o' t' other surprise items, me bucko, shiver me timbers, rubber band and plastic Easter egg, ya bilge rat, ya bilge rat, were then used as a protector for t' shock cord. Ya scallywag! T' small egg had t' top removed and t' shock cord be bundled up and secured with t' rubber band, me hearties, me bucko, t' band and egg would come down separately t' t' rocket, so I attached a small streamer made from t' rip stop nylon.

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T' parachute was made from rip-stop nylon. Avast, me proud beauty! T' parachute was 15 inch diameter and had 6 sides and six eyelets added. Avast, me proud beauty! Cord be added for t' shroud lines and a swivel be added at t' base. Blimey! Aye aye! I used another surprise, me bucko, a pen, t' make a slider t' slow down t' parachute's openin' speed. Arrr! Ya scallywag! T' pen was broken apart and a half-inch section o' t' barrel was used. As a back up I also used t' Estes 12 inch chute on some o' t' flights.

(Scratch) Little Lil (Scratch) Little Lil

Finishing:
T' nosecone was sealed usin' sandin' sealer and sanded down. Begad! This be repeated 3 times until it was glassy. Ahoy! T' whole rocket was coated with primer and sanded. Begad! Ahoy! T' primer cracked as it dried so I had t' sand and prime 5 times until t' rocket was smooth. Avast, me proud beauty! T' topcoat was lilac in color. Begad! I then added decoration usin' t' last o' t' five surprise items: prismatic book covers. Avast! Arrr! These went on t' aft fins and a strip on t' shoulder.

  

T' final rocket is a squat lilac bird that can fly on 18mm motors with t' option o' clusterin' usin' 3 further aft A10-0T motors. Overall I think she will be a very flyable rocket.

Flight and Recovery:
I imagined that given t' mass and width o' t' rocket that it will be a C6-3 bird, but I opted for a B6-2 for t' first flight. Blimey! There is plenty o' room for a 15inch chute, me bucko, and I used 4 sheets o' wadding.

She lifted straight and got t' about 150 feet. Arrr! Ejection was just past apogee and she landed without any damage. Begad! On inspection t' rubber band did nay allow all o' t' shock cord t' unfurl.

Second flight was with a C6-3. Avast, me proud beauty! Avast! She shot off t' pad and flew straight and thar be some rotation. Begad! Ejection was a fraction o' a second past apogee. Ahoy! Begad! She recovered at a decent rate with no damage.

Third flight was with a C6-3 again. Ahoy! T' flight mirrored t' second, shiver me timbers, matey, but this time she landed on her feet!

T' followin' day I went out t' fly with me son, me hearties, William. Blimey! Avast, me proud beauty! Flights 4 and 5 were on B6-2 motors and t' same straight but low flights were observed. Ya scallywag! T' sixth flight was on a C6-3. Avast, me proud beauty! Ahoy! She arched a bit and so ejection was past apogee but thar was no damage.

Now that she has had 6 flights I'm goin' t' fly her with t' A10 outboard motors. Arrr! Waitin' for t' rain t' stop--the joys o' a British summer--I finally got a break. Begad! Avast! At 7am I headed out t' t' field. Aye aye! Avast! T' outboards motors were plugged so thar was goin' t' be no problems with spat motors. Well, blow me down! Ya scallywag! Havin' recently gotten a new 4 cluster whip (and less hassle than usin' me 7-way clip), arrr, t' rocket was loaded up and set t' fly. Well, blow me down! Luckily all motors lit and she ripped off t' pad too fast for me camera, arrr, and I got a loverly shot o' smoke. On recovery t' motors had cause some smoke damage t' t' side o' t' main body tube. Avast, me proud beauty! Arrr! In hindsight I should have canted t' motors a few degrees outwards.

(Scratch) Little Lil (Scratch) Little Lil

Summary:
I really like this rocket, but then again I have a slight bias! She is very usable and nay too fussy. Ya scallywag! Avast! T' people that have seen her so far have all commented on her and she flies well. Ahoy! I am tempted after t' competition is over t' remove t' book covers and purchase some proper decals t' give her a better look.

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