Sunday, October 04, 2015


I'll preface this post by noting that the Coleoptere/Stovepipe/Coccinellida build has officially stalled. It will be on the back burner until I run across another ring tail option.

My latest project was inspired by the Estes MIRV.  After the third sustainer from my Estes MIRV was recovered from the soy beans, I set a plan to launch the sustainers off a standard rod. Then this popped into  my head: If a finless, induction stabilized rocket is fun, maybe a cluster would be even more fun. I don't know why I am so obsessed with a class of rockets that run such a high risk of being single use. Maybe the same reason I used to like 29mm 'Machbuster' style rockets, which were usually single use but for another reason.

The build is underway and, for lack of photos, I offer a 3D rendering from a 'what-if' Rocksim model.


As mentioned, this is induction stabilized but I didn't bother segmenting the body tube so I could make an intermediate section transparent.  The body tubes are 18" BT-60s. there will be an air gap (not finalized) and a set of 3.5" induction tubes, The nose cones are plastic Easter Eggs that happen to fit the BT60 perfectly. These were hot-glued onto a coupler. I just couldn't justify wasting nice balsa cones on the rocket. Plus the Easter Egg cones are nice and light.

I was kicking around 18mm vs 24mm mounts for C6s or C11's, respectively. It turns out the 18mm CRs were backordered and I have C11's, so I went that way.

I am also finalizing the interconnection between the main body and induction tubes. I have given up of making the induction section easily replaceable. Just too much work for such a build. Instead, I will merely try to ease the pain of the inevitable repairs.

Then there are those fins. I am trying to decide whether I should go totally finless or go with some tiny ones. Since I have one totally finless rocket, I don't feel the need to be a purist. Also, my experience with the Saturns is that, if there is a small amount of natural stability, you get some flight during the coast phase (vs. a wild tumble).

The name was chosen to let everyone know that, unlike the MIRV launch, there will only be one piece to avoid. (The name tagged onto this photo is an older placeholder and I can't easily get rid of it).