After reading two different build threads in a different forum I decided to build one of these Estes D Region Tomahawks and add a few upgrades to it. First off, the kit alone is wonderful. It went together easy and even included a nylon 18" parachute.
First thing I did was to make it a 29mm instead of a 24mm. I cut 1/8" plywood centering rings for the new motor mount and added an Aero Pack retainer. I willl be putting one of these on every rocket that I can from now on, they are awesome.
To cut the new centering rings I took the plastic centering ring that is included with the kit and cut off the inside flange and fit it to the 29mm tube. I then just traced the pattern to the ply and cut it out a bit wider than needed and sanded it down to size and then glued them to the motor tube using wood glue and filleting them with epoxy.