Estes Black Brant III, Part 8, Reinforcement Coupler

Lately, BT-50s in every build have buckled after recovery. Even with a soft landing the BT-50 crimps down the inside spiral above the engine mount.

I made an interior coupler from Crossfire BT-50 tube.
1 1/2" was cut and slit straight down its length.
The tube was overlapped and slid into the Black Brant tube.
Push it to the inside diameter and mark the edge with a sharp pencil.


Enlarge the picture to see the cut line.

With sharp scissors cut just to the side of the pencil line.
This should give you a tight slip fit in the body tube.
The edges of the split coupler will butt tightly together.




The coupler will be pushed in place with the engine mount. It will sit right above the upper green centering ring.
Apply glue far enough inside the tube for the coupler first, slide it in place with the engine mount. Remove the mount.

At the bottom of the engine mount tube is a pencil line. Apply glue in the main tube, the mount is pushed in up to the line.