BT-70 based twin 24mm upscale of the original 'LandShark'
HOW TO BUILD A SHARK:
Start with a Fliskits twin 24mm canted
motor mount kit for maxi Deuces Wild
or scratch build your own.
Use the cut out template supplied with
the kit but locate it 3/4" lower on the
tube for deeper MMT installation.
Yes, I used 30 min epoxy on the motor
mount kit, this baby's gonna rock the
Take Apogee BT70 size plastic nosecone,
and first cut the shoulder 3/4" long, then
notch the shoulder on opposite sides to fit over
canted motor mount. A razor saw works great on
this... Heat tops of the cut outs carefully with a lighter
or ye to soften up the plastic and use a spent
(preferred) Estes D or E motor casing to gently push
sides in for the canted MMT's to clear. Do a little at a
time and try until it fits snug...
Here's another view,
it's easier to see from this angle.
Dry fit everything together
before glueing, these babies usually
take a little bit of tinkering,
some patience, a gentle touch
and about two bottles of cheap
red wine per step to
get the fit right....
Epoxy the motor mount in the BT-70
When it's dried, epoxy the chopped up
nosecone, now a tailcone in.
While that mess is drying, go ahead and cut up
three plywood or basswood fins. I used 1/8"
aircraft lite 5 ply. Free form your fins to loosely
resemble your fav shark, or scale up the ones
on the bottom of 'LandShark' page like I did.
Root cord is 4.25", semi span is 4", edges
beveled on belt sander... It takes a bit of playing
to get the root to fit the nc ogive shape right.
Use 30 min epoxy.
After carefully lining up and tacking in the
dorsal and pectral fins ( Hey, we're talking
about a Shark here, not any rocket with just
'forward' fins )
with CA first, it starts to look like a Shark!
When you're happy with the alignment, do all the fillets
with 30 min epoxy. These are big fins and if one motor
misfires, there'll be a wallop of twist on them...
Remember to sand glazing off the tube and tailcone
I used 1/8" ply on these too,
these are easier since the root cord is not curved. Root
cord length is 3" as well as the semi span too...
Front of the fins is 4" from the top of the tube. Ahh... that
reminds me, the trailing edge of the main fins is 1"
forward from the tip of the tail cone. Or ye, this really
ain't rocket science...
|I made the coupler into a baffle
with a couple of home baked bulkheads all drilled up
and a half of a Dutch Chore Boy stainless steel
pot scrubber off the Wallyworld epoxied together.
A length of 300#
Kevlar cord threaded thru the baffle and tied into the
bottom end of the baffle makes for a perfect
shock cord mount... I epoxied this into the bottom body
tube only. Front tube is a friction fit with a permanently
attached Fliskits maxi Deuce nc for a center break
(Oops - I did it again... playing in the background)
Here she is
with the original !
Next up will be the launch lugs
- 1/4" Acme conformals -
motor retention if any
- I hate taping RMS casings -
paint job and decals,
then it's off to the launches !!
Weight at this point 10.5 oz.
Yes, I'm trying to keep her light,
after all she's supposed to be a
'lean, mean, cloud-eating machine'
TigerShark! had her maiden flight 02-18-2006
Check out the 'Videos' page for a clip
of my latest Shark going up on twin
I wanted to launch her with twin
E9-6's but due to strong high
altitude winds causing me to fish
3 rockets off the trees I decided to keep
her closer to the ground. Even so
you can see a nice little 'twirl' on her
smoketrail right after burn-out...
TigerShark! flew again on 03-18-2006
Here she is finally with a halfway decent paintjob !
I had some issues with my new airbrush on the
first time around, so I had to redo her furcoat...
She is still missing all the decals, now my printer is
on a fritz - again ! ( I'm having it with Lexmarks )
This time I let her roar on twin E9-6's, she did quite a
corkscrew, so next launch is going to be with a bit
noseweight and more power...