MAXI Deep Space Transport

[Fore Check]

So I was sitting around earlier this summer trying to come up with something else to upscale. My basic criteria for this decision is usually: More than just 3 or 4 fins and a cone, and that I haven't seen one elsewhere yet.

This is what I came up with: a BT70 based, 24mm cluster powered, 167% upscaled Estes Deep Space Transport.

 

[Fore Check]

It turned out to be a fairly challenging build.

The parts came from the usual subjects: Mostly Balsa Machining for tubes and centering rings, Sandman turned an *awesome* custom cone out of balsa, and Phred over at Excelsior did the decals.

 

[Fore Check]

Here's a neat "head-on" shot."

 

[Fore Check]

All of the wood is 1/8" balsa, and the launch lug is 1/4". The main airframe is BT70, the side boosters are BT60. The bell shrouds on the Strap-On-Boosters were wrapped out of heavy cardstock, just like the instructions. But I used a lite ply CR5070 in the ends, and a pair of lightly sanded light ply CR5060's in the forward ends of the shrouds. This allowed me to put a BT50 engine mount in the side boosters that is canted with the centerline of the bell shroud. I put a balsa nose block at the top of that canted engine tube, and will use plugged engines in the side boosters.

I simply used a 2 engine cluster arrangement in the central airframe. The result is a linear, 4-engine cluster arrangement with the outer two engines canted away from the center in a pseudo-Deuce's Wild fashion. The rocket is very light empty (I haven't weighed it, but it's all balsa and basic kraft paper tubes glued together with Elmer's Pro-Bond wood glue.) Should fly great on 2 E9-6's alone, or get crazy and put a pair of E9-8's in the center and a pair of E9-P's in the outboards.


Here's a view of the business end:

 

[Fore Check]

Here's a "top" view

 

[Fore Check]

And finally, here's a detail shot of a little extra decal I put on the bottom of the rocket. It was provided on the sheet, so what the heck.

 

[sandman]

Well now....this one was a suprise!

You kinda slipped this one in "under the radar". No build pics...just a cool finished model!

Most Excellent!!

I really wanna see a launch pic with all those motors burning!

 

[Rocketmaniac]

Very nice indeed!!!! Can't wait to see launch pictures......

 

[Fore Check]

Originally posted by sandman
You kinda slipped this one in "under the radar". No build pics...just a cool finished model!

I have a terrible habit of not taking build pics. I just get to working and gluing and stuff.

I really need to get better about that.....

 

[Fore Check]

Originally posted by sandman

I really wanna see a launch pic with all those motors burning!

A launch pic with all four engines lit will be *delicious*!!!!

I modified this pic with some cheaply added yellow lines to approximate where the flames will be, just for added visual reference.

 

[kelltym88]

WOW. Awesome job Forecheck. Man, I can't keep up with you, but I've got something in mind.... Again, nice job.

 

[SwingWing]

Very Nice!!

 

[BobH48]

Awsome job!

Liftoffs should be spectacular with all four motors!

 

[marvSRG]

Great job--I love it!

....was that a whoopee cushion you were using as a prop? Ha.

 

[Big J S.A.M.]

you suck.

Just kidding... can't wait to see it launch dude.

 

[Rocketcrab]

Yes, indeed, very, very nice. My oldest son has been bugging me to do an upscale around a BT-80 using a Maxi Honest John nose cone. But you know, I kinda like your idea better!

 

[OKTurbo]

Excellent!

Outstanding job Forecheck. You are the upscale master.

So how long will we have to wait for flight pics? Hopefully not 'til spring.

 

[Fore Check]

Originally posted by OKTurbo
Excellent!

Outstanding job Forecheck. You are the upscale master.

So how long will we have to wait for flight pics? Hopefully not 'til spring.

Spring?

Now that I've moved to Iowa, that starts when.... June?



The answer is: Probably. Or 27. or something.....

Thanks, John. Until I master the art of 'glassing, I'll not be a master of anything. Clusters are one thing. Building them to withstand the high thrust curves of 29mm+ composites is another.

 

[astronboy]

This is just fantastic!! Great Job!! I too cannot wait to see flight pics..... 4 E9s... that's E36, right?

Phred

 

[MetMan]

Originally posted by astronboy
This is just fantastic!! Great Job!! I too cannot wait to see flight pics..... 4 E9s... that's E36, right?

Phred

They have 30 newton-seconds impulse each so it would be a G36 (50% G with 120 N-S).

 

[BobH48]

I thought that any rocket that contained more than 125 grams of propellant was considered High Power.

The Estes catalog says that an E9 contains 35.8 grams of propellant so 4 of them would be over the limit.

Please correct me if I am mistaken. I believe that at our club launches you have to have your L1 to fly a 4 motor E9 cluster.

 

[MetMan]

It might be, but the equivalent motor is still a G36.

 

[jflis]

Originally posted by BobH48
I thought that any rocket that contained more than 125 grams of propellant was considered High Power.

It is actually a mix of things that determine if it qualifies as a "model rocket" vrs a "high power rocket"

Propellent weight (125 grams)
Liftoff weight (1500 grams)
Total impulse (320 N-sec)

Exceed any (or all) of these parameters and you are no longer a "model rocket" by NAR definition.

So, **technically**, you could have a 35 pound rocket powered by an A8-3 and you'd be in trouble. Seems to me the biggest trouble would the the ridicule of your fellow rocketeers, but what do I know??

 

[BobH48]

A pair of E9-8's in the center and a pair of D11-P's in the outboards would keep it under the 125 gram propellant limit and still provide an awsome liftoff show in my opinion.

 

[Fore Check]

Someone needs to modify that high power ruling using propellant mass as a basis. Seems *stupid* to me.

It should be based on something related to thrust: Average thrust, total impulse, something like that.

Perhaps it should be a function of burn velocity of the propellant and the mass of the propellant (which is DIRECTLY proportional to the energy contained....)

Oh, well.

My opinion is worth something. I'm sure of it.




EDIT: I just asked my wife, and well.... let's just say that the value of my opinion is diminished.

 

[Bowhunter]

Hey Forecheck I got a couple of 29/40-120 RMS motors the next time you come our way I also have a few G64 loads. I think you need to build a motor then the real bug will set in cause then you will want HIGH POWER. I mean it I got the cases you and you Brother can use If you would like to try it.