Quest Cobalt Clone Answers

Last year I built a clone of the new Quest Cobalt kit.
I know - Why build a clone of a available kit?

A few reasons:
1. I had extra Quest PNC40 nose cones and 40mm body tubing at hand.
2. I wanted a good schoolyard rocket for all the A6-4 engines I'd bought.
3. I'm cheap.

I did my best to clone the model from the rendering on the Quest website. Kit instructions weren't posted yet.
Mine went unstable twice using the recommended A6-4 engine.
The rocket was retired.

A few days back, more kit instructions were added to the Quest website, including the Cobalt. See HERE

My clone was close, except for the engine mount.

I used an Odd'l Rockets XLEH (long) engine hook. My engine mount tube was then 1/4" longer than the 2 3/4" tube supplied in the kit.

The above drawing I made shows the engine mount extending 1/4" out the rear of the model.The Quest instructions show the end of the engine tube flush with the end of the 40mm main body tube.

On a rocket this small and stubby, the CG is critical. It would have to be built as shown in the instructions to be stable.
Lesson learned.