Estes Black Brant III, Part 4, Engine Mount and Nozzle

TIP: You'll find it easier to cut the engine hook notch if the nozzle is left attached to the nose cone. There is just more to hold onto.

Remove the back end off the nozzle.
Now you can score the raised area that opens up into the hook movement relief.
Don't cut to the edge but go a little inside the raised block.

The rest of the raised lip was shaped down with a rectangular file.

Now you can the nose cone from the nozzle end.

A dry fit over the engine mount didn't allow enough movement of the engine hook.
Looking inside the nozzle, there was a raised area inside and above the notch.
This bump was cut and filed down. The engine hook moves more now allowing an engine to be slid in.

The entire engine mount was dry fitted to see how the nozzle would fit against the centering ring.
A Kevlar line was added below the upper ring. The upper ring will be glued lower than the Estes Black Brant instructions say. I wanted the ring over the top bend of the engine hook.

The inset picture shows the fit of the nozzle when butted up against the lower ring.