Construction

Building started with a roll call. I wanted to make sure that everything was accounted for and that nothing was bent, crumpled, or damaged. I highly recommend doing this with EVERY rocket you build. You should always check the quality of the components before building so that it can be replaced or fixed. If there is a weak link in the structure, bad things can happen. I don't expect this from Aerotech, but there have been several reports about problems with the nose cones.

Another thing everyone should do before building is to STUDY the instructions. Aerotech has pretty good instructions and the steps are in a logical order, but some of the illustrations could be better.

The actual building started with the adapter (build this first because it will be used to push back the thrust ring and flange). Afterwards, measurements are taken on the motor mount and the motor hook is inserted through a 1/4" slot that you cut. The thrust ring and flange are now glued together and pushed up until it butts up against the back of the motor hook. Aerotech says to cement them in place, but I decided against it since the fit between the ring and tube is so tight and the hook is so long that it's hard to glue anything in place at all.

Now comes the challenging, part-the FIN-LOC rings. They are so tight that the front 1/8" of my motor tube us torn and the layers of paper are separated. To get them into place, I suggest gently tapping them into place with a rubber mallet or small hammer.

What comes next is super important. DO NOT glue the FIN-LOC rings in place until you have test fitted the fins and they fit properly. Slide the centering ring into place and make sure it does not interfere with the fin placement, then remove the fins and glue the FIN-LOC rings and middle centering ring in place. I used Gorilla Devcon 30 minute epoxy throughout the motor mount assembly (because most super glues will deform the plastic and because I had never used liquid epoxy before).

The only problem I came across was the epoxy taking half an hour to set. It runs like syrup. I simply kept rotating the assembly and everything worked fine. In the future, I will use 5-minute epoxy.

Now you make four 1/4" slits at the top of the assembly that are 90 degrees apart, stretch out the cooling mesh, and cement the baffle in place. Unfortunately, I made a stupid mistake and glued in the baffle before I inserted the mesh. After about 5 minutes of wondering what to do, I ended up cutting away the first 1" of the tube, peeling the paper away from the baffle, inserting the mesh, replacing the baffle, and gluing it in place with the front centering ring over that.

Tie the shock cord to the screw eye and screw that into the baffle. The whole assembly is then inserted into the lower body tube and the fins are snapped into place so that the assembly doesn’t move. Now the whole thing is glued into place, and the fins are removed and tacked down, both at the root edge and where the fin tab meets the motor mount.

Then insert the last centering ring and add the launch lugs, and the bottom half is finished!

Now comes the coupler. I highly suggest test fitting the coupler, sanding, and test fitting again until it is snug, but still slides in easy enough so that the glue doesn’t grab before the coupler is in all the way. When all was said and done, there was still a 3/32 gap between the two tubes, so i filled and sanded it down with two-part epoxy clay from Apogee. The rocket was then set aside to dry overnight.

Now is where the strakes come into play. The strakes need to be shaped by hand, and that can be a bit of a challenge. Make several shallow passes with a new razor knife close to the lines that you draw onto the plastic. Then sand down the last little bit and wipe away the dust and any remaining flash. Here is where I found the one, and only, gotcha. There is a wrap (similar to an Estes fin wrap) that marks where the strakes go. The problem is that the launch lugs are already glued on. To avoid this, either use a straight edge, or wait to put on the lugs.

Draw the lines at least 6" past the lower body tube. Now glue on the strakes.

Next tie the parachute to the shock cord and tie the shock cord to the nose cone. The assembly is done!