Construction 

An interesting decision on the design of this rocket was the body tube sizes.  The main body tube and tube fins are 0.9080 inches.  This is just barely larger than a minimum diameter standard (A,B,C engine) rocket.  Motor mount outside diameter is 0.74 inches which gives you about 1/6” difference in diameter.  Split this in two (for each side), and this gives you about 1/12” clearance between the two tubes.  I guess the reason to do this was simply so they could add an internally mounted engine hook.    Had they not done this, the rocket would have been minimally smaller and a lot simpler.  But you’d have to friction fit the engine.

Setting up the motor mount, again the mount comes with a single “long” (about 1 inch) centering ring. 

Since I am always running out of centering rings, I cut this into four individual rings, and used two of them for this kit (pretty much the standard “two ring” motor mount.) 

I was glad I did this.  The instructions don’t tell you to cut a slot in the centering internal diameter to accommodate the engine hook (in fact, I suspect it would be difficult.)  I found that even cutting a slot in my two cut rings, it was a REALLY tight fit to slide the rings over the motor mount tube AND the engine hook.  But it did work.  

The instructions have a nice marking guide ruler built in, which really helps.

I DO really like the shock cord attachment, which wraps around the forward end of the engine hook where it pokes through the motor mount tube. 

A key part of this kit is canting the tube fins.  Yes, this is a case where you intentionally put the tube fins on “off center.”  Instructions for this involved marking a canted or angled strip on each of the tube fins, then trying to sand this down so the tube  “will simply collapse in” (a quote from instructions).  Then you mark the center of this canted strip, and line it up with a true axis aligned mark on the fuselage (main body tube).  It was six separate steps for this.  I guess this might work, but seemed to me very complicated and easy to mess up. 

All the placement areas were of the tube fins and main body tube were lightly sanded in advance to rough them up a bit for better adhesion.

I did it differently. I marked the canted “strips” on the tube fins.  I then cut two pieces of 1/32 inch balsa the length of the fin tubes, basically each was about 1 mm x 1 mm x 2.5 inches  (the length of the tube fin.)  Had I thought ahead I would have made them 2.0 inches as the tube fins are 2.5” long and they overhang the tail of the fuselage by 0.5”.  I call these Balsa Fillets.  These are easy to line up and glue onto each edge of the strip marks on the tube fins.  These can then be filleted to the tube fins before you attach the tube fins to the main body tube.  This “locks in” the angle of attachment.   Once in place, the tube fins literally fall into canted alignment against the main body tube. You just have to pick which marker you want to line up the tube fin up with.

The other advantage of this technique is that it allows you to separately paint the tube fins and the body tube.  (I find it extremely difficult to mask the tube fins if I want them a different color from the body tube AFTER they are already attached.)