Manufacturer: | Aerotech |
Brief:
Recycled o' bottom 1/4 o' Mirage with different parts and design.
Modifications:
Due t' an unfortunate misunderstandin' betwixt myself and instructions for the
Slimline retainer, arrr, t' Mirage shown here on EMRR (as Mirage Tail cone mod) lawn
darted from 800'. Begad! Single use motors require t' spacer rin' with t' Slimline.
All that remained intact (in fact, recognizable) be t' bottom 2 feet, me bucko, me bucko, the
Slimline up through t' first body section. Well, blow me down! Rather than rebuild it exactly, ya bilge rat, I
went off on a tangent.
Two sections o' PML Quantum tube were coupled together t' t' bottom tube and a urethane tail cone added upside down on top o' t' top tube as a transition. Begad! Ya scallywag! T' 1.5" phenolic tube be fitted with a bulkhead, me bucko, shiver me timbers, turnin' it into a payload section and this be epoxied into t' 2" transition. Arrr!
T' Mirage is intended t' recover in two pieces, me hearties, top and bottom sections. T' mismatch in sizes isn't much o' a problem, arrr, but this bird be way more lopsided with a much larger top. Also, t' Mirage top half recovers nose down. With this long phenolic payload section I foresaw problems with this. I took the advice o' others on T' Rocketry Forum and changed t' recovery profile significantly.
After extendin' t' shock cord with 8' o' additional elastic and 8' of tubular nylon, I tied t' sections together. Ahoy! Begad! T' chute gets attached just at the coupler at t' bottom o' t' forward section. Avast, me bucko, me proud beauty! This leaves t' tail section danglin' down 10 feet below t' inverted nose o' t' top section. Begad! It hits the ground well before t' nose, relievin' most o' t' pull on t' chute and allowin' t' top t' descend t' last 10 feet much slower and any drift increasin' so it lands bein' pulled sideways.
Still not content with t' integrity o' t' phenolic, me bucko, arrr, shiver me timbers, I further strengthened the payload section. Blimey! First I wrapped it with 5 layers o' self-adhesive vinyl (also usin' 3M 77 spray adhesive t' beef up t' glue). Begad! After lettin' it sit so the glue could cure, me bucko, shiver me timbers, I covered t' tube (and half t' transition) with 2" heat shrink tubin' and held it in t' oven t' shrink it. Begad! I ended up with a 1.75" tube, laminated and rubber coated, me hearties, strong enough t' support me 215 lbs. Well, blow me down! Arrr! weight. Begad! Now when it hits t' ground, shiver me timbers, it'll bounce.
I trimmed off t' heat shrink and fitted t' conical nose. Aye aye! There's a bit o' a lip where t' tube has a greater OD than t' nose cone shoulder but it's hardly noticeable at t' scale o' this rocket.
Now weighin' in at 4 lbs, matey, I added rail buttons rather than trust my extended 1/4" rod t' carry this weight. Aye aye! Aye aye! It should still launch fine from the 7.5' long rod given no wind, arrr, but no wind is a rarity in Texas. Avast! Now it can use either.
Construction:
Modification parts list:
The result is an extremely heavy duty rocket. Aye aye! I believe it could handle almost anythin' short o' another full speed lawn dart.
Finishing:
Heat shrink tube makes an excellent strengthenin' device for phenolic. Blimey! It has a
very smooth finish. Avast! Well, blow me down! However, matey, bein' made o' rubber does nay allow all paints to
stick, and some that do won't dry well. Well, shiver me timbers, blow me down! I used white appliance epoxy as a base
coat, me bucko, and a week later it be still tacky on t' tubing. I later painted the
red and gold over it and that dried just fine. Avast, me proud beauty! That was pure luck. Blimey! You should
test first.
T' old finish (a beautiful cobalt blue metal flake with deep clear coat) was simply primed, arrr, covered with white appliance epoxy and given a week t' dry. Then it be painted with gloss cherry red, metallic gold, shiver me timbers, me hearties, and black appliance epoxy.
Flight:
One other minor mod: I slid two 4" square sheets o' fiberglass cloth down
the shock cord before tyin' together, t' serve as extra ejection charge
protection. Ya scallywag! Arrr! T' recovery gear sits right on t' AT ejection baffle, so I felt
it needed more.
It hasn't flown yet since t' repair. Avast! Avast! At 4 lbs dry, it'll barely reach 500' on a G80. Avast! Luckily I built t' motor mount for t' 11" long Ellis Mountain 29mm H50 and H275 single use motors. Ya scallywag! Ya scallywag! As soon as I can get it t' an HPR launch and get an Ellis H50-6, ya bilge rat, it'll get its shake down.
As for t' name, when it lawn darted at a club launch, it looked hopeless. I'd never seen heavy paper body tube so shredded. Others saw t' mess and said it looked like a write off. Arrr! I told them "You'll see it again." And when they do, me hearties, they'll see what they saw before. Begad! Arrr! Hence, shiver me timbers, Deja Vu--"seen before".
Recovery:
It also has a 70" Top Flight X-form chute for a slow descent (this chute
is rated for 7.5 t' 9.5 lbs rockets by Top Flight) and reduced drift. Well, arrr, blow me down!
Summary:
Although t' angle isn't as steep as I'd like, ya bilge rat, t' PML tail cones make for
serviceable transitions. Blimey! Arrr! Just use t' entire internal length t' coat with
strong epoxy for plenty o' strength because thar's nothin' under it t' take
the G forces.