Inside diameter of U.S. Rockets 2.7" vs. BT-80

[jcsalem]

I'd like to know if the inside diameter of the USRockets 2.7" airframe matches the inside diameter of the Estes BT-80 (2.556")? The USRocket web site says that the inside diameter of these tubes is 2.6". Is that just rounded off or is it really that large?

I know the USR tubes are quiet a bit thicker but I'd like to be able to couple in airframe sections from other BT-80 sized rockets (e.g., Estes, PML, etc).

-- Jim

 

[lalligood]

Originally posted by jcsalem
I'd like to know if the inside diameter of the USRockets 2.7" airframe matches the inside diameter of the Estes BT-80 (2.556")? The USRocket web site says that the inside diameter of these tubes is 2.6". Is that just rounded off or is it really that large?

I know the USR tubes are quiet a bit thicker but I'd like to be able to couple in airframe sections from other BT-80 sized rockets (e.g., Estes, PML, etc).

-- Jim

I would say that the numbers from USR are pretty accurate. They are a bit larger than LOC 2.56 tubing (& nose cones for that matter), which would mean that they're bigger than BT-80. That slight increase in diameter allows USR to sell the Warp 3 kit, which has 3 29mm motor tubes in it. I cannot fit 3 tubes (without distorting the tubes anyway) into a LOC 2.56 airframe.

HTH,

 

[jcsalem]

Here's the word from Jerry Irvine:

"2.60 ID. It fits BT-80 nose cones loosely.

Our couplers are loose inside or you can apply 3 layers of tape to an Estes coupler.

2.70 OD
"

 

[doug_man_sams]

Lance wrote:

> [USR 2.7" tubes] are a bit larger than LOC
> 2.56 tubing (& nose cones for that matter),
> which would mean that they're bigger than
> BT-80. That slight increase in diameter allows
> USR to sell the Warp 3 kit, which has 3 29mm
> motor tubes in it. I cannot fit 3 tubes
> (without distorting the tubes anyway) into a
> LOC 2.56 airframe.

You should be able to get 3 LOC or TT 29mm tubes
into a LOC2.6" tube with very little distortion.
The thicker-walled 29mm MMT from PML and Giant
Leap are a different story. You'd about have
to form the airframe into a triangle

Doug