Megga Mag - upscale Minie Magg

[brianc]

I've made enough progress on this project the last several months and
the build pics are starting to tell a story, so I thought I'd post a few.
Besides, not much else to do while the JB Weld cures....

This is an upscale LOC Minie Magg using 7.75" concrete form tube and a foam
and 'glass nose. As I got further into the build, I decided this would become
my HPR cluster bird with interchangable MMTs.

 

[brianc]

I started with the nose. I cut disks of sheet foam insulation and stacked
them on a 3/4" dowel. The disks were cut to approximate the shape of
the curve, reducing the amount of sanding (and the mess).

I also cut a section of the concrete form to make the shoulder. This was
split and a sliver removed to fit inside the BT. A 3/4" ring would become
the actual shoulder (seen in the attached wrapped in a protective layer of
blue tape).

 

[BHP]

Cool! Any more info/pix coming?

 

[brianc]

I don't have a lathe, but fashioned a sort of mill using the dowel and
some PVC on my Skill bench. I used my Dremel with the 90 degree
attachment and a sanding drum to handle a lot of the initial shaping.

On the bench is the stencil of the desired nose shape. The shape
was determined mathmatically and drawn using a string compass.

As the nose approached the desired size, I attached the shoulder.

 

[brianc]

After final shaping, I applied fill-n-finish and sanded some more.

Then I cut four gores of 6oz. fiberglass, CA'd these on the shoulder
edge and layed on the US Composites 635. After a bit of squeeging,
I covered the whole thing with a leg from a pair of (sheer toe) panty hose.

 

[brianc]

Here's another angle of the shoulder. I inserted a disk of 1/4" plywood
with the U-bolt for the recovery attachment.

 

[Delta-IV]

Brian,

Looking good..where are going to launch the thing, Big Oaks Ranch (too small)??? I'd love to see it.

I need someone to show the ropes on MPR, that's my next big project.

-Delta IV-

 

[rokitflite]

Originally posted by brianc
I covered the whole thing with a leg from a pair of (sheer toe) panty hose.

Is this what you used rather than fiberglass cloth?

 

[brianc]

The next major component was the fincan. I wanted interchangable
motor mounts and also TTW fins. So I made an inner tube to
attach the fins- three wraps of 90 lb. kevlar then a 1" section of
fiberglass mat.

Another U-bolt on the forward CR will become the recovery anchor.

A pair of 10-24 T-nuts in the aft CR will anchor the MMT assembly.

 

[brianc]

The MMT assembly consists of a forward CR that inserts into the
inner tube and will rest against a pair of triangle braces.

The aft CR is larger (just slightly smaller than the BT) and is secured
to the rocket with the T-nuts in the main CR.

I've built an initial pair of mounts based on the cases I currently own.
I have a pair of 29/40-120, a pair of CTI 38mm 1-grain, a 38mm 2-grain,
and a 4-grain. I also have a 29/180-240 system, but figure I can adapt
down if I want to slap that into the center spot.

Hiding under the blue tape in the attached pic, is a pair of ACME 3/4" conformal
launch lugs. These were freebies from NARAM-46- my wife just rolled her
eyes when she opened the goodie bag. She said "And just what do you
think you'll ever build that'll need these?" I just gave her the 'ol rocketeer
smirk and said, "Just wait"...

 

[brianc]

And here's the result thus far...

I have this great sunscreen windshield shade flame decal I picked up at
the auto parts store- it's black, blue and purple. I'm going to wrap it
around the top of the BT, right at the NC shoulder. Then I'll paint the NC
a matching blue, the BT black and the fins purple to match the flames.

Should look sweet!

 

[brianc]

Originally posted by Delta-IV
Looking good..where are going to launch the thing, Big Oaks Ranch (too small)??? I'd love to see it.

Curently targeting first flight at NEFAR in August. Probably too soon to try for this weekend.

 

[rokitflite]

Originally posted by brianc
I covered the whole thing with a leg from a pair of (sheer toe) panty hose.

Is this what you used rather than fiberglass cloth???

 

[plasticpaul]

That is looking pretty sweet !!! What engines are you planning on? Have you projected an altitude for it yet? Let me know if you want some help with a chute.

 

[brianc]

Originally posted by rokitflite
Is this what you used rather than fiberglass cloth?

No, I used 6oz. fiberglass first, then finished it off with the panty hose.

The hose actually served two purposes- it helps squeeze out a bit more
resin and it gave the 'top coat' a very smooth finish.

 

[rokitflite]

Originally posted by brianc
No, I used 6oz. fiberglass first, then finished it off with the panty hose.

The hose actually servered two purposes- it help squeeze out a bit more
resin and it gave the 'top coat' a very smooth finish.

Very cool! Sort of a budget vacuum bag! It looks GREAT!

 

[brianc]

Originally posted by plasticpaul
That is looking pretty sweet !!! What engines are you planning on? Have you projected an altitude for it yet?

I need to weigh the components before I start any serious sims...

First flight will certainly be with a central CTI H or I and AT G64's (maybe) outboard.

Jason (jetra2) has a similar configuration on his Big Red and Thumper Jr. He's
already challenged me to a drag race...


At some point down the road, I expect to pickup some electronics and maybe air-start
the outboards.

 

[Rocket Guy 1317]

I just got ask why launch logs??? Why not rail buttons on something that big??? BTW looks great.

 

[brianc]

Originally posted by Rocket Guy 1317
I just got ask why launch logs??? Why not rail buttons on something that big???

1) I had the lugs, and just had to use'em - see the NARAM-46 comment from my wife.
2) Plus, NEFAR (where this prolly fly most) has more rods than rails and
3) I'll probably put buttons on too. I'm not worried about the drag.

 

[Brian62]

looking good, keep it up!

 

[bigone5500]

Where can I find that airframe tubing?

 

[brianc]

Originally posted by bigone5500
Where can I find that airframe tubing?

That's standard concrete form tube (AKA Sono-tube). This is Sakrete
brand; Quik-crete is an equivalent brand.

You can find either at Home Depot or Lowe's Home Improvement.

Be careful when selecting tubes- They vary in OD (they're labeled x inches "nominal").
If you have a project that'll require more than one tube, buy'em at the same
time and compare at the store. If you're looking for a particular size,
be sure to take a tape measure with you.

 

[brianc]

Wow, it's been a while... I finally got this bird painted. I'm not sure
I'm entirely happy with the blue NC transition to the flame decal... One
of these days I gotta get an air brush/gun.

Needs a few more coats of Future and I still need to hook up the recovery
harness, but I'm planning a first flight on August 12th @ NEFAR.

 

[brianc]

Here's a closer look at a chunk of the decal next to the fin. The Kryon
Plum really is a great match.

 

[rstaff3]

Looks awesome! I like the exchangeable mounts