Experi-MENTAL

Hi, matey, arrr, me name is Geoff Marshall. Ya scallywag! I have been a BAR for about 2 years and am currently t' president o' t' British Columbia Rocketry Club. Avast! Well, blow me down! I am also a member o' t' Canadian Association o' Rocketry and hold a CAR level 3 certification. Arrr! Begad! I hope you enjoy this presentation o' me Descon 9 entry.

T' idea for this rocket came after flyin' t' new Estes E9's for t' first time this past September. Blimey! I liked t' long burn time and t' gobs o' smoke and they perform great in small, me bucko, matey, me bucko, light rockets.

T' conversation leadin' up t' this design sort o' went like this.

Me: I like t' new E9's
Other Guy: Yeah, ya bilge rat, but nay much good for bigger models.
Me: True, but you could do a nice cluster.
Other Guy: Or boost it with a D12.
Me: Or a cluster o' D12's!
Other Guy: Hmmmmmmmm!
Me: Hmmmmmmmmmmmmm!!!

Thus Experi-MENTAL was born!

• I wanted a relatively big model, me hearties, 2" X 36" or so
• At least a 2-stage design..... Begad! maybe 3-stage
• Initial booster stage would be a cluster
• Sustainer would fly on an E9

Here's a screen capture o' t' final design

(Click for larger image)

PARTS & CONSTRUCTION

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I chose LOC/PRECISION components for construction as I feel they offer the 'best bang for t' buck'. Aye aye! Blimey!

Parts List:

Airframe:	LOC 2.56" - 1@16.5" sustainer and 2@ 5" boosters
Nose Cone:	LOC 2.56" plastic
Motor Mounts:	LOC .95" - 2@4" booster1, 1@4" booster2 and 1@4" sustainer
Couplers:	LOC 2.56" - 2" for each booster
Centerin' Rings:	Homemade from .050" kraft paper card stock - 2 per stage
Fins:	3/32" balsa laminated with printer paper & epoxy - 3 per stage
Recovery:	8' o' 1/2" tubular nylon & homemade 18" ripstop nylon chute
Guidance:	Acme Conformal rail guides
Misc:	Industrial Formulators 30 min. Aye aye! epoxy used throughout construction

 

Below are some pictures taken durin' construction
(Click on t' small images t' view full size)

Airframe completed boosters & motor mounts under construction	All 3 stages complete with motor mounts installed	Completed & ready for paint
T' business end o' stages  recovery system installed	Stagin' & recovery layout	Paint, matey, decals & rail guides applied
Another shot o' t' finished bird	Jared demonstrates how t' insert a rocket into little brother Seth's nose

FLIGHT REPORT

Experi-MENTAL had her maiden flight at t' British Columbia Rocketry Club's model and HPR launch held in Pemberton Meadows B.C. Blimey! Blimey! on Nov. 18th 2001. Arrr! T' sky was clear and t' temperature be hoverin' around 0°C (32°F).
Experi-MENTAL was loaded onto a 6' 80/20 rail with 2 X D12-0 in booster1, shiver me timbers, 1 X D12-0 in booster2 and a E9-6 in t' sustainer. Ahoy! Blimey! Avast! Blimey! Blimey! Blimey! At ignition both motors in booster1 lit up together and t' rocket came off the rail nice and straight . Blimey! Blimey! About 150' up booster2 lit and t' rocket snapped over at about a 45° angle :-( She continued t' arc over down range and, me bucko, you guessed it, t' E9-6 in t' sustainer lit up right on cue. Begad! Blimey! So now we have the sustainer headed for t' ground about 3/4 o' a mile down range powered by a motor with a 3 second burn time, needless t' say I gave up any hope o' the rocket surviving. Arrr! Blimey! We did see a puff o' smoke from t' ejection charge but at that distance you couldn't really tell if it was before or after impact. Begad! Blimey! Blimey! Blimey! Blimey! Blimey! We then proceeded t' launch t' rest o' that rack and I ended up makin' a trek into t' surroundin' woods t' help retrieve someone's L2 bird. On returning, another club member offered t' help me trek out across t' muddy, me hearties, semi frozen potato field t' retrieve what was left o' Experi-MENTAL. We found booster 1 just 100 yards or so down range with one fin hangin' loose at t' fillet. I looked up t' get a line o' site t' booster 2 and t' remains of t' sustainer and notice another club member headin' towards me wavin' his arms and yellin' something. On meetin' up with him I discovered nay only had he recovered t' intact booster 2 but t' also completely intact SUSTAINER!! It appears that t' ejection charge fired just high enough above ground t' get the laundry out and save t' bird.... Ya scallywag! no zippers, shiver me timbers, no dings, ya bilge rat, nay even a scratch! Experi-MENTAL will fly again!

Post flight analysis:

Close inspection o' t' stages revealed a scorch mark down t' inside of booster1's coupler. Ahoy! It appears that t' 2 motors in booster1 burned through at slightly different times and caused t' stage t' jam at an angle until the ignition o' booster2 kicked it off. This is what caused t' sharp change in trajectory and sent t' rocket on it's long downrange arc. Begad!

T' fix:

For her next flight I am goin' t' shorten t' coupler on booster1 from it's current exposed length o' 1 1/8" down t' about 3/4" and sand it t' a slightly looser fit. Avast! Blimey! Hopefully this will allow t' booster t' eject cleanly even if t' tandem motors pop at different times. Begad! Blimey! Booster2 will remain unchanged as it appeared t' perform as planned. Begad! Blimey!

Overall I am very happy with how this rocket turned out and plan on flying it again in various different configurations, me hearties, booster1 and sustainer only, booster2 and sustainer only and just t' sustainer as a single stage rocket. Ahoy! If Estes does release t' E9-0 I will definitely fly her on a full load... Begad! 2 X E9-0 t' E9-0 t' E9-8..... Aye aye! Good-bye!!