PML Lunar Express Build, Part 4, Engine Mount

The bottom hole of the tail cone is smaller than the diameter of the engine mount tube. It had to be slightly widened to get a good friction fit of the tube.

If you are using engine retention you should plan ahead for how far the engine tube extends out the back of the tail cone. There is a supplemental page included explaining engine mount position if using a retainer.

Here I'm checking how far to recess the lower ring inside the interior tube. The low ring should sit 1/16" to 1/8" to allow for another inside fillet. Do a few dry fits before any epoxy.

On the left is the dry fit with the tail cone in place. The extended engine tube will be covered by the screw on retainer.

On the right shows the engine tube in place and the shock cord strap extending out the back of the lower ring.