3D Printing Rockets

 The Thrifty Rocketeer blog continues...

A couple of rocketry friends of mine have invested in these new 3-D printers, and are looking for applications.  So far, we have stumbled across a Dragon's Head nosecone that mates with a BT-50 tube,  a spare rocket motor rack, and now, some small disposable tumble recovery fin cans and nose cones.

The smallest of these parts slide onto the rear of an 1/2A3-4 or similar 12mm motor, while a similar nose cone slides onto the top.  Depending on how old or dried out your motor might be, these can be snug or looser, depending on the humidity.

There's another batch that fit a B6-4 size motors  (18mm) with a similar fin can and nose cone.

What I haven't told you yet, is that there is also a small launch lug ring embedded in the sides of each of these parts, so they should be aligned when they are mounted on a rocket motor. 

 But the real neat factor is the cant of the fins.  That is, the fins are all purposefully twisted or canted, so that the "rocket" will spin like the dickens while going up. It will probably also spin on the tumble recovery descent as well, except it's unclear if you'll be able to track it. (Shades of the Mosquito rocket!)

I have also seen three other variations on this 3-D printing, including a nosecone with escape tower, a short Apollo 11 style nosecone.  But neither of these two samples I have seen fit an existing motor.

I've also seen a "big wheel" style spinning copter, called the "Whirl and Hurl 24".  This carefully crafted craft is basically a wheel or spinner with 4 canted spokes, an outside ring, and a screw-on retainer for D-sized motors (24mm).  This looks to be the most valuable of the bunch, and is also the largest by far.

Now, my friend who printed all of these says that they cost over a dime a piece for most of them, and the implication is that they can be given away at school talks, rocket launches, or wherever.

However, I question the value in doing this:  In essence, we're showing the public that all they need to do is attach fins and a nosecone to a rocket motor and launch it with no skill, no construction and no recovery.  The immediate gratification of seeing a rocket go whizzing into the air doesn't teach a kid anything or instruct them at all. (***But I could be wrong.)

For years, we have resisted the image of just some drink-guzzling yahoos who launch fireworks when no one is looking.  I'm not certain having 3-D rocket parts at a cost of pennies to give away is a step in the right direction.

But what do you say?
This has been the Thrifty Rocketeer saying, "Save your balsa: it teaches wood working skills!"

EDIT:  We took the printed rockets out for a test launch today and I learned a couple of valuable things.  

1.   The fins are extremely thin, and the slightest pressure will snap them off. It appears that the fin was scored or had a flaw halfway down the fin, so that it snapped off cleanly in a parallel break to the bottom edge.  We decided to launch it anyway.
2.  The loops on the side of the nosecone and the fin can are for the launch lug, not for any connecting shock cord.  As they were white, I snipped a short length of parachute line from a replacement chute and tethered the two together.  It was loose and floppy when we launched.
3.   The Whirl and Hurl 24 went like a bat out of hades.  It was a great launch, and the descent was fast, but fortunately did not injure the wheel at all. It is a tumble recovery.
4.   We're still looking for the A8-3 rocket which I described above.  On a field of grass, we never saw it again.  We heard the pop but never saw where it fell.  With a slight wind, we looked downwind but had no success.  That was the last of our efforts to launch 3-D rockets today.