Brief:
Scratch 4" V-2. Flies on H through J 38mm motors. The nose has interchangeable weights so the rocket can be properly weighted for any given motor. I use a silk 36" chute I got from AEROCON.

Construction:

• 1- 4" dia LOC body tube 8.5" long. Glassed with 6oz cloth and 30 min epoxy. This rocket has no payload section but one can be added inside the nose cone.
• LOC 4" NC for the nose
• 4" PML NC for the boat tail, which is cut to 11.5" exposed length.
• 4 fins made from 3/16" 4 ply plywood, also glassed with 6oz.
• 1- 3/16" 54mm centering ring,
• 2- 3/16" 4" centering rings.
• All rings have a 38mm hole and are birch plywood.
• 14" 38mm LOC motor mount.
• 3/8" strap Kevlar® for shock cord. 2 pieces of this form the harness that mounts to 2- 1/4" by 3/4" u-bolts, which are located on the top CR of the MMT. There is 20' of Kevlar® from there to the nose cone, which mounts in a similar fashion to 2- u-bolts mounted on a bulkhead inside of the nose cone.

Nose Cone:
This is the most complex area of the rocket. I cut the shoulder off of the LOC NC to 2.5". I sanded the tip of the NC flat and drilled a 1/4" hole in the tip. I took 15.5" of stainless steel 1/4" allthread and ran that through the hole. Before that I used a small 1/4" washer and 1/4" nut and secured that about 2" from the tip of the allthread. Then inserted the allthread from the shoulder side of the NC through the hole in the tip. That gave me 1" exposed through the tip. I used another 1/4" washer and nut and secured the allthread tight at the tip. Then took some 1/4" fender washers which are about 1.3" dia and slipped them down the allthread from the shoulder side. I got some round/flat lead fishing weights in various weights ranging from 3 to 5 oz, drilled 1/4" holes through the center, slip those down to the big washers, put another big washer on top of the weights and then used a 1/2" stainless steel tube about 8" long to push down on the weights. I used a bulk head with the same fender washers on each side, put that over the tube and secured the bulk head with a 1" section of 1/4" coupler. All metal parts are stainless steel. There are two u-bolts on the bulk head for recovery harness attachment.

I can change the rockets weight in under a minute. The only problem was the allthread sticking out of the tip of the NC. I was going to fake it out with glass and epoxy, but since I had cut the tip off the PML NC for the boat tail, I had a perfect tip to put over the allthread. I took an extra piece of allthread, put a nut on it and heated it up with a torch. Then took the tip of the PML NC and sunk it into the HOT nut that was on the allthread. This worked out better than I had hoped. I now had a tip that I can screw onto the allthread, and I finished it off with sand paper to make a perfect fit.