My latest and first strictly high power rocket project was a LOC Minie-Magg. As you will see, I changed a few things to beef it up.  I may want to put a J350 into it someday.  Hope you find it interesting.

Above is a standard LOC Minie-Magg kit. I was disappointed to find that “through-wall” construction for this kit meant just through the wall. The fin roots penetrated the airframe wall but did not extend to the motor tube. Knowing I wanted to put big motors in this rocket meant I would have to modify it. The Minie-Magg is a short rocket with the center of pressure is close to the CG. Since I was going to add weight to the rear by adding fin root extensions, I needed to find ways minimize the addition.

Above are the standard fin (top) and the modified fin (bottom). To keep the weight down in the rear, I cut holes in the extensions on the modified fins. I then contoured the fins and finally covered them with 2 oz. fiberglass. Note: I did have to extend the fin slots in the air frame for the modified fins.

Also to cut down on weight, I decided to try a new material for my centering rings. The reddish material in the photo above is a honeycomb composite made from phenolic impregnated Nomex with fiber glass skins. This material is made by the Hexel Corporation. It is twice the thickness of the plywood centering ring but only half the weight. It is very strong. I got this material at Boeing Surplus for $2.00 / lb. I added one plywood centering ring forward as the motor tube was extended to accept a 38/720. Plywood was used here to keep the weight near the CG.

The 2 photos above show the centering ring/fin arrangement.

The photo above shows the dry fit. The one below was taken after glassing the fin extensions to the motor tube. After this picture was taken, I also glassed the fin extensions to the inside of the airframe.

After gluing in the aft centering ring she is ready for paint.

I used a U-bolt through the forward centering ring for the harness attachment. The harness connects to it with a "Quick-Link." Note the forward centering ring is also glassed in from the front.

The recovery harness was made from 1/2" tubular webbing. I chose to sew the D-rings (a friend of mine does industrial sewing). Overkill? Perhaps, but it should last a long time and it look neat too.

To add more stability to the beast, I added nose weight in the form of a bolt inserted in the nose cone. The final touch was the addition of an Aero Pack motor retainer.

Well here she is, all ready for the maiden voyage. Now we just have to wait for decent weather...

...and we got just that in January at Monroe. The maiden flight was on an H123 and was flawless. I just hope being a shark, she doesn't feel inclined to head for the swamp.

I hope you all found this interesting. If any one has questions or comments, you can contact me through the Northwestrocketry e-mail list. Keep 'em flying

John Norris
NAR # 77544
Level 1