BT-80 Fiberglass Airframe Available?

[lowga]

I'm looking for a fiberglass airframe for a reproduction that I'm doing of an Estes kit. Need a BT-80 sized airframe. Google searches are not turning up much.

 

[tfish]

2.6" FG tubing looks close..

https://www.madcowrocketry.com/2-6-g12-thin-wall-airframe/

Tony

 

[Jozef]

Wildman also has 2.6 thin wall FG airframes. Several of his kits use them

 

[cbrarick]

high power doesn't follow low power body tube sizes (it's a thing..)
However you could roll you own. I know plenty of TARC teams who do, and the competitive (NAR) guys do too. Just google it up.

 

[lowga]

Actually, Mach 1 Rocketry is changing that tradition. They've released several great fiberglass kits with BT airframes. Perfect, low cost introduction to HPR build techniques, and just damn fun to fly.

 

[Scott_650]

Actually, Mach 1 Rocketry is changing that tradition. They've released several great fiberglass kits with BT airframes. Perfect, low cost introduction to HPR build techniques, and just damn fun to fly.

Right now Mach1 only lists BT-60 and smaller tube sizes - they do have 54, 65 mm and larger diameter tubes and kits listed. Hopefully, if their kits are becoming as popular as they seem to be, they’ll expand their BT sized tubes. I have an unbuilt BT-55 kit on hand, a BT-60 and another BT-55 kit enroute. The BT-60 kit uses what looks like an Estes nose cone and it fits perfectly. Bigger BT sized kits from Mach1 would be awesome!

 

[caveduck]

Madcow 2.6 thinwall FG tube FT-26THIN is a near exact match for the heavy wall Semroc BTH-80. The ID of 2.560" is only 2 mils larger than the nominal 2.558" of BT-80, so regular BT-80 nose cone shoulders and centering rings will fit. The OD is .040 larger than standard BT-80 though, but nearly identical (2 mils less) to BTH-80. Mach 1 lists a similar 65mm FG tube with quoted dimensions ID 2.55", OD 2.64". Mach 1's BT-60 tube is the thinnest commercial FG tube I've seen listed. There are only a couple of companies that actually make this stuff and I'm not sure what their process limits are, but a .021" wall BT-80 might be pushing it. You could probably make things look decent by sanding down the front of the .040 wall tube to match the nose cone OD.

Now I'm going to have to add Mach 1 to my OpenRocket parts database b/c the BT-60 FG is a unique size not previously seen. Their other available airframe sizes all seem to match industry norms for FG tube size. For some reason they are not separately listing their small BT-20/50/55 FG tubes for sale, nor giving the tube specs.

 

[lowga]

Caveduck--that's dynamite intel. I'm hoping to use the BT-80 fiberglass tubing to complete the new Boyce Aerospace Honest John kit which calls for an 18" BT-80 tube.

I wonder how the Madcow tubing compares to the G12-2-6 product offered by Wildman Rocketry?

https://wildmanrocketry.com/collections/fiberglass-1/products/g12-2-6?variant=1273927139335

 

[caveduck]

The Wildman and Madcow tubing should have similar dimensions, but I have not been able to directly confirm except for a few sizes where I happen to have the actual tubes. The 2.6 size is a wildcard since Madcow only offers it in the .040 wall...the Wildman might be .060; they don't call it "thinwall". Unfortunately Wildman gives no dimensional data on their site, and I don't own any of their nominal 2.6" tube. It definitely will not be thinner than .040" though.

BTW everything I have figured out about tubes in the last few years is here in my OpenRocket parts database on github: https://github.com/dbcook/openrocket-database Grab the repo and look in data/tube_data.txt and data/body_tube_data.xlsx for all the research.