| Coreman 3 Scratch built rocket based on a Pringles can |
| This rocket started out as part
of a project to build rockets for each of my kids, all quite small at
the time. I was in that phase of my return to rocketry (BAR-dom)
where everything cylindrical got condsidered for rocket use. My
family presented me some Pringles cans, and I set about building two
rockets, one for each of my middle two kids. With a fly cutter, I managed to cut some rings which would center a BT-60 tube - ie, a standard sized tube - in the Pringles cans. The idea was that the standard size tube would allow me to more readily use common rocket parts such as rings and nosecones.
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| In the pic above, two of the
BT-60 sections have been cut to a little shorter than the Pringles can,
and rings have been glues in place. |
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The two rockets were expected to
be quasi-twins - mostly the same, but with some differences, such as
nosecones. The one on the right hasn't been glued yet, and would
end up quite different with no Pringles. The one on the
left was assembled as shown. For both rockets, the exposed body tube is BT-55. |
| Eventually,
hopes of using the Pringles label as part of the finish were
abadoned. After slotting it for the fins, it soon became apparent
the thin label paper was just too fragile to take the normal handling
it would receive. In the pic at right, the can has already been sanded to smooth out the high spots. As it turned out, I never did get the raised spiral completely flattened out. The fin root treatment is angled balsa from the hobby shop. I sanded it a bit to increase its 90° angle. That helped reduce the gap beteen the wood and the body tube. Once the glue dried, these "fillets" were sanded to shape. Lots of sanding. So much sanding, that I'll do things differently next time  |
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The fillets were in fact applied
long after the fins were mounted. The rocket sat in limbo for 2+
years waiting for inspiration. That arrived as a present from
Buzz McDermott. He gave me a bag of stuff he had cleaned out as
he was packing for his move to Minnesota. Among the presents were
a thick-walled BT-70-ish tube with matching nosecone. At some point it occurred to me to add them to the front of this rocket. So I cut several inches off the BT-55, then mounted the BT-70-ish tube at the top of that using some 55-70 centering rings. Then I added transitions between the skinny BT-55.and the fatter tubes on either end, finally covering the hideous step between the Pringles can and the BT-55. At this point, it was starting to take shape as an interesting rocket. After that, it was a matter of applying the silver and white paint, followed by strips of blue trimkote for the roll pattern. |
| The rocket uses an early version
of an interchangeable motor mount sysem as shown at right.
Options include 1x24mm, 1x29mm and 3x18mm. A fourth mount was
later added that can work with this rocket. |
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Designed to go with my improved interchangeable motor mount sysem,
this mount includes a very thin lip which, like the large rings above,
functions as a thrust ring. The tubes include 2x18mm and 2x13mm. Thus, motor options for the Core3 are many, ranging from a pair of A's plus a pair of B's all the way up to 29mm power. |
| Here's a good liftoff pic of the Core3 on a composite motor. |
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| Coreman 3
October 2005 |
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Not long after becoming a BAR in 1999, like so many other rocketeers, my family and I began collecting paper tubes in anticipation that they might be suitable for flying. So a Pringles rocket was very much a possibility with four snack munching kids emptying the cans. The original intent was to transition from the ~3" Pringles can down to BT-55. The hope had been to keep the Pringles can artwork intact for the lower rocket section, but after the fins were added, the can was quite scarred. None of the pics show it in its ugliest state, but it was basically the upper half of the left pic - BT-55 with nosecone - and the lower half of the middle pic - scarred can with fins and no transition. It was tail heavy and butt ugly. It was so ugly that it sat idle for nearly four years, coming dangerously close to the scrap pile before work resumed in 2005 when a heavy walled BT-70 and mating nosecone was given to me. After cutting the BT-55 shorter and mating the BT-70 ahead of that, two 1/64" birch ply transitions were added along with fin fillets made from balsa. At that point, the rocket's shape became appealing and the work momentum picked up with the nosecone and forward section getting paint and stripes of monokote trim. Then it sat on the back burner for a couple more months. Finally, I got to shoot some Plasticote metallic silver last night. It looks great. The photo doesn't really convey how good it looks. I only hope I find a clear coat that preserves the shine and doesn't screw it up. Anyway, the rocket has interchangeable motor mounts and can be flown on one 29mm motor, one 24mm motor, three 18mm motors or a combination of two 18's and two 13's. I think this is a pretty kewl rocket. Doug
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