Monday, September 6, 2010

Freedom 7 Build Part 19 Engine Mount


I'm doing the posts in the same order as the instructions, were now up to page 6.
The engine mount is pretty straight forward, I won't spend much time on this. I'd rather concentrate on the capsule, tower, fins and paint.

This is the rear centering ring. Notches were made for the engine hook with a #11 blade. The center section was removed with a small, square diamond file. Using a flat file gives the notch a cleaner, flatter bottom than I could get with a knife.


Here's the finished mount.

TIP:
Dr. Zooch has solved the problem of the engine mount tube tearing at ejection.
Sometimes ejection charges are so strong it kicks the engine back hard against the rear of the hook. The front end of the hook can tear back through a BT-20 tube.

Just forward of the tape wrap is a reinforcement band cut from the cardstock wrap sheet. (It's hard to see in the picture.) This wrap is glued immediately behind the engine hook notch. A drop of CA is applied to the wrap below the engine hook slit.
The combination of the wrap and hard CA glue probably doubles the strength of the BT-20 tube.

No comments:

Post a Comment