Aerospace Speciality Products Kappa 9M (3 x 18mm)

Aerospace Specialty Products - Kappa 9M (3 x 18mm) {Kit} (KK9M-3/18)

Contributed by Peter Clay

Diameter: 1.64 inches
Length: 43.25 inches
Manufacturer: Aerospace Specialty Products
Skill Level: 2
Style: Cluster, Scale
Rating
(Contributed - by Peter Clay)

Kappa 9M photoI received the Kappa 9M from Aerospace Specialty Products as a prize for my entry in R.M.R. DesCon 6. I deeply appreciate the vendors who have contributed to the design contest in this way. I've wanted to get a review to EMRR, but my opportunities to fly a rocket this size are limited, and I wanted to log more flights before posting.

The Kappa 9M is a scale model of the Japanese sounding rocket. ASP makes three kits of it: a smaller one for a single 18mm motor and two versions in this larger size, one for a single 24mm motor and one for a cluster of three 18mm. The last is the version I have. It's over 43 inches tall, the larger diameter is 1.67" (classic BT-60), and its color scheme is silver and fluorescent red.

Construction materials are classic "pre-plastic" Estes style with a couple of notable improvements. The nose cone and transition are turned balsa, and the eight fins are basswood. The elastic shock cord is anchored by means of a piece of Kevlar® cord tied to a coupler which joins two sections of the BT-60 sized tube. Overall, the rocket is very light for its size.

The instructions are detailed and well-written, printed in an informal script type face. Scale information is minimal, and refers the builder to Rockets of the World for additional data. The instructions alone produced for me a satisfactory "eyeball scale" model. I was a little unclear about what was meant by "steel" color, but I added black to brush-on silver enamel and got an acceptable effect. The one rub-on name decal supplied was a treat to use and looks extremely nice in place.

Kappa 9M photoConstruction was fairly easy overall, with a little care to the carving of the beveled fin edges. . Because both halves of the rocket are very long, I did wish the large shoulder of the balsa transistion, which was the separation coupling, could have been longer. Fit of some parts could have been a bit firmer, but overall the quality was very high.

The lower section was supplied as two different lengths of the 60 sized tube, and the Kevlar® shock cord anchor was tied around the coupler that joined them. The resulting splice was difficult to hide, and I felt it could have been better had the splice been made at the edge of one of the red stripes, probably the forward edge of the aft stripe. This would have required the longer section to be several inches longer than it was, but still not as long as the 50 sized tube that makes up the "upper stage."

The kit includes ASP's "heavy duty" chute kit, whose main feature is suspension lines running over the top of the aluminized mylar canopy. It was quite a project to assemble and tricky to fold, but looked foolproof. Alas, fools are so ingenious...

So Here's What Happened...

I built the kit and planned to fly it twice at our September 2000 meet in Sheridan. I had a set of B6-4's in my range box, but since the weather was perfect, I bought a card of C6-5's at the Tammie's Hobbies booth on site and put those in it first. After the fact I realized that the instructions called for C6-7's, which might have saved the day.

This was an extremely fast liftoff and a high, pretty flight. I was quite surprised that something as long as this could go that fast -- much more like an Alpha than a Mean Machine. It ejected on the way up, still climbing at a good clip.

The "heavy duty" chute shredded. It crumpled up into a ball the size of a soccer ball within the canopy of suspension lines, providing drag, but not as much as a fully open chute. Still the rocket would have been undamaged had it not struck a lawn chair. As it is, the only damage was to strip one of the basswood "booster" fins from the surface of the tube. The fin was repaired in a few minutes, but the chute was a loss. I thought the tape disks had come loose, allowing the canopy to slide up the lines, but postmortem revealed that about half the lines had cut clean through the Mylar, starting at the edges and pulling straight away from the sticky stuff. There were several tears each close to halfway up from edge to center..

I rebuilt the parachute with a piece cut from a "space blanket." It isn't actually the same material, but is similar in appearance. I've taken the liberty to add Trim Monokote reinforcements to the underside where the lines pulled through the material before, and I suggest this modification to future builders. The second flight, in April 2001, was as perfect as I've seen on three B6-4's. This time the parachute fully opened. Except for a slight scar where the one fin was re-installed, the rocket still looks new. I have the feeling it will be around a long time and become one of the the standard items on my club launch agenda.

I heartily recommend this kit to cluster lovers and sport scale fliers. It's not cheap but it's a good value, and ASP deserves our support for the quality product they're putting out.

Construction/Finishing: 4.5 -- I've mentioned the seam/splice in the main body tube, and the balsa fittings could be firmer, otherwise excellent from tip to tail
Flight/Recovery: 4.5 -- My "heavy duty" chute failed the first time, probably because I didn't give it enough delay
Overall: 4.5 -- for a light but sturdy, attractive, straight-flying cluster experience

Flights

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