Tuesday, April 7, 2015

The Estes Scion - Spare Parts Elimination Vehicle?

When I first read about the existence of the new Estes Scion on Chris Michielssen's blog, he hypothesized that this might be an S.P.E.V. - a model rocketry term meaning Spare Parts Elimination Vehicle. The rocket has a 3-inch diameter tube, and the nose cone and fins look just like the Estes Leviathan's - though the Leviathan has four fins, and they are flipped around from what you see above so they are swept back.

Estes Leviathan
My Scion just arrived today, and there here are a few interesting things about it.

First of all, there's no card - no art work depicting the finished rocket, no Estes logo - nothing. Just a bag of parts.

Because of this, you can see inside. What you find are two 3-inch diameter tubes, of the same length as the upper section of the Leviathan. The Scion, like all of the larger Estes kits, has through-the-wall (or TTW) fins - meaning that the fins have tabs which go through slots in the body tube to anchor them more securely , but neither of the tubes are slotted to accept the fins. Some rocket kits from some companies require you to cut your own slots, but Estes doesn't really do this.

The dead giveaway, though, is the package of fins. The Scion design has three fins, but the kit contains four. Furthermore, the wood grain runs parallel to what would be the trailing edge of the fins on the Scion. Normally, you find the wood grain running parallel to the leading edge. This is the standard practice, and with balsa fins, it's important, because it's stronger. With these plywood fins, it probably won't matter. But it seems pretty obvious that, rather than being based on Leviathan fins, these are simply Leviathan parts repackaged.

This isn't necessarily a bad thing - a lot of rockets have similar appearances. Mixing and matching parts gives each rocket its character.


I have read that Estes is getting out of the Pro Series II mid power rocket builder kit game. If this is true, it's a sad thing. I love the look of the Leviathan and the Ventris rocket, and if I happen to mess up the build, or to destroy my rockets in a crash, I like knowing that I can always get a replacement.

Estes Ventris
So, it looks like we have an SPEV on our hands.

Don't get me wrong - I love the look of the Scion, being a cool twist on the Leviathan design. But I feel a little odd about it, knowing it's basically a bag of Leviathan parts - especially if that means the Leviathan is going away.

Note: Estes used to have a rocket called the S.P.E.V., and this might be where the term comes from. It was not a kit you could buy; rather, they would send it to you if you ordered a certain amount. It's a rare rocket, and it's interesting-looking. I have no idea what kits the parts come from, but it looks a bit like a NASA mockup. I doubt they still send it out, but people do clone it from time to time.

From rocketreviews.com

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    1. Hi Daniel,
      On the Estes S.P.E.V.(Kit K-59),
      The low BT-70 tube was from the Estes Little Joe II kit, the upper section was pretty much a Thor Agena B.