Friday, January 9, 2009

Payload Carriers

I have a number of interesting payloads, mostly in the BT-55 (1.325" / 33.7mm OD) and BT-56 (1.346" / 34.2mm OD) sizes.

Although they're only half a millimeter different, the NC-56 nose cones will not fit in BT-55 tubes and NC-55s need tape to fit in the BT-56s, and I don't recommend that. I have the Cosmic Cobra and Astrocam boosters in the BT-56 size. I prefer the CC because it has an all-plastic motor mount that isn't all beat up like the Astrocam's booster's mount. They can carry the Astrocam aerial camera, the CC heliocopter-blade nose cone, and the MaxTrax altitude tracking capsule I found in the Woods of Doom.

The only interesting BT-55 payload I have is a payload canister from my Loadstar named Alexi Leonov. It's an 11" long section consisting of a plastic BT-55 to BT-60 adapter, a 5" payload tube, and 2-1/2 caliber PNC-60. 3.25" of the payload tube is clear; the rest is partially or totally occupied by the connecting parts. I also have the BT-55-based GBU-24 Paveway III and Bullpup, but both are scale models, not payload carriers.

I tend to fly mostly small-diameter models. Besides the 2 BT-56 and 3 BT-55, I have the 3" Rama, 2" BT-200 SpaceShipOne, the BT-60 Cloud Hopper and Pigasus (originally Baby Bertha), and the Gauchito (more in one second on that). The rest are 24mm BT-50, 18mm BT-20, made from 6mm pens, and odd sizes.

I have two items of mystery size. The Gauchito is between the BT-56 and BT-60 sizes, I suspect it may be rare BT-58 as seen here. I also have an old reddish-brown nose cone that's free, including shipping to anyone who identifies it. It's ever-so-slightly bigger than an NC-56, but not as big as the Gauchito. I think it might be an NC-139. It's a 2-3/4 caliber ogive that might have been red at some point. It was a gift from the rocket gods.

About body tube sizes: the Estes numbers are roughly sequential from BT-5 to BT-101; 123, 123, 139, 200, and 394 numbered tubes are odd sizes. The number does not indicate the actual diameter. See here for a good history of the sizes and here for an absolutely complete and incomprehensible spreadsheet of tube sizes.

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