High Power Model Rocketry

BT-3.90 x 6.5"

BT-3.90 x 6.5" - Main image
$5.22 $6.96 In stock

This 6.5-inch section of our 3.90-inch cardboard airframe is a practical choice for builders working on a 4-inch Cyclotron project or similar high-power rocket builds. It offers a ready-to-use tube segment for your airframe needs.

  • Measures 6.5 inches in length with a 3.90-inch diameter.
  • Constructed from sturdy cardboard material.
  • Suitable for use in a 4-inch Cyclotron build.
  • Listed as a close-out accessory item.
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Express Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

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Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

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United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

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Customer Reviews (5.0 / 5 · 5 reviews)

Eli M. ★★★★★

This six-inch segment was exactly what I needed to extend my rocket's nose cone section, and the cardboard feels sturdy enough to handle the ejection charge. The fit with my 4-inch airframe was spot-on with no sanding required.

Ella C. ★★★★★

I needed a longer tube for my 4-inch Cyclotron build and this 6.5-inch section saved me from having to splice two shorter pieces together. The cardboard feels sturdy enough for the high-power flights I'm planning.

Amelia J. ★★★★★

Cut this to length for my high-power rocket build and it fit perfectly into the airframe slot. The cardboard feels sturdy enough to handle the ejection charge without any flex.