I want to build an upside down rocket. Any tips?

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I was thinking about making a rocket with the fins on the top and the nose cone on the bottom. Actually, it would be a boat tail transition so the motor could poke out the bottom. Instead of a nose cone on the top of the rocket, there would be a cap over the parachute. My question is: could such a design be aerodynamically stable, but still look like an ordinary rocket turned upside down?
 
I was thinking about making a rocket with the fins on the top and the nose cone on the bottom. Actually, it would be a boat tail transition so the motor could poke out the bottom. Instead of a nose cone on the top of the rocket, there would be a cap over the parachute. My question is: could such a design be aerodynamically stable, but still look like an ordinary rocket turned upside down?

The problem is that the CP ends up far forward of the CG; so no, not stable. You could build something that fools the eye into thinking the rocket is upside down, like with invisible plexiglass fins at the bottom.
 
Maybe if you had massive, clear, polycarbonate fins on the bottom.
 
Of course you could make it a tractor kind of system with multiple motors coming out of the top at an angle and pulling the rest of the rocket behind it.
 
Of course you could make it a tractor kind of system with multiple motors coming out of the top at an angle and pulling the rest of the rocket behind it.

I like that idea. Might be a bit difficult to do, but it could work. I’ll run it through rocksim and see what I get.
 
I like that idea. Might be a bit difficult to do, but it could work. I’ll run it through rocksim and see what I get.

Super easy to do. You will have the most stable Rocket at the launch but no one except a few crazy oddroc fliers will believe you. Tractor motors are just too funny looking and they put the scare into folks.
 
Make an inverted mean machine with the launch rod going up the middle center line! Maybe it will fly better than a traditional super roc. Then you to can have stories you can only tell close friends. :)
 
If you successfully light a cluster, 3 B's or C's in fin tip pods may be interesting. It'll need three little parachutes in the pods, or ducts running to the central tube volume.
 
Bring the motors down to a three quarter forward can't. Disguise the motors as ram air inlets. Give it a Russian style scale look then flip it in line. Three 24mm to a BT 70 and standard motor deployment. Mindsim nearly complete.
 
Make an inverted mean machine with the launch rod going up the middle center line! Maybe it will fly better than a traditional super roc. Then you to can have stories you can only tell close friends. :)

Interesting idea. SuperRoc rules as follows

Super-Roc Altitude Competition shall be scored as follows: the length in centimeters of the model, as measured from the tip of the nose cone to the aftmost end of the motor nozzle, up to the maximum length for that category, shall be awarded as static points. If the model has more than one motor, the length shall be measured to the motor nozzle closest to the tip of the nose cone. No additional points are awarded for any length beyond the maximum.

If you put all your engines up front, and there is only ONE nose cone and it is on the TIP of the rocket at the TAIL end, do you still get the points for the distance? Or are those negative points? Or can you not call it a nose cone if it is at the tail end? What if you mount it pointed forward?
 
Interesting idea. SuperRoc rules as follows

Super-Roc Altitude Competition shall be scored as follows: the length in centimeters of the model, as measured from the tip of the nose cone to the aftmost end of the motor nozzle, up to the maximum length for that category, shall be awarded as static points. If the model has more than one motor, the length shall be measured to the motor nozzle closest to the tip of the nose cone. No additional points are awarded for any length beyond the maximum.

If you put all your engines up front, and there is only ONE nose cone and it is on the TIP of the rocket at the TAIL end, do you still get the points for the distance? Or are those negative points? Or can you not call it a nose cone if it is at the tail end? What if you mount it pointed forward?

You're a gonna need one of dem fancy NEW YORK PINK BOOK LAWYERS!
 
I think it would be cool to have a fin-can that is on top when the rocket is on the pad, then as soon as the acceleration starts, it slides down to the back of the rocket and locks in place.
 
Putting the motors at the front adds weight to the nose, which is good. Probably still need some fin-age on the tail end, colorless perspex or the like.

Oh, and remember...even though the pointy end will be down, not up, the flame is supposed to point to the ground. ;)
 
I remember seeing an upside down fatboy mounted on a (fake) Estes launch pad that was the fin unit. Might have been on the rocket dungeon site a few years back.
 
Active stabilization using the front fins as control surfaces might give you a fighting chance. Might.

And I have it on good authority that the leading Pink Book lawyers are concentrated in the Chicago area.
 
Look in Sport Rocketry NOV/DEC 2007 page 12 there is an Upside down Fat Boy on a fake launcher that is actually the fin unit. The pink book guys don't seem to have had a problem with it.
 
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