Semroc - Javelin {Kit} (KV-16)

Semroc Javelin

Semroc - Javelin {Kit} (KV-16)

Contributed by Chan Stevens

Construction Rating:
Flight Rating:
Overall Rating:

Diameter:	0.76 inches
Length:	12.70 inches
Manufacturer:	Semroc
Skill Level:	1
Style:	Sport

Semroc Javelin

Brief:
The Semroc Javelin is an 18mm minimum diameter kit based on a 1965 Centuri design that is easy to build and flies great.

Construction:
The kit includes:

ST-790 body tube
Balsa nose cone
4 Balsa laser-cut fins
Thrust ring
12" plastic chute
Kevlar/elastic shock cord combo
Waterslide decals

The instructions were well written and easy to follow. This would probably rate about a skill level 1 to 1.5 and was a quick build.

Construction starts by tying the Kevlar shock cord to the thrust ring, which anchors it nicely. The thrust ring is then glued into the body tube.

The fins are laser cut and are attached based on a fin guide template at 90-degree orientation.

The balsa nose cone uses a screw eye for attaching the shock cord. My cone was slightly tight and needed a light sanding for proper fit.

The chute is a basic plastic cut-out chute, using tape disks to attach the shroud lines.

Finishing:
I painted following the stock color scheme, starting with a couple of coats of primer to fill most of the grain and spirals, followed by two coats of gloss white. I then painted the nose cone bright red, and the fins a nice yellow. There's also a pretty nice waterslide decal to top things off.

Construction Rating: 5 out of 5

Flight:
First flight went up on a B6-4. This rocket raced off the pad and went to the very limits of my middle-aged eyesight before deploying the chute. The recommended delay of 6 would have been much better as my 4 second delay was a bit early.

Second flight was on an A8-5, with perfect deployment.

Considering how high I went on a B, I'm waiting for perfect conditions to fly on a C (or else I'll swap out the chute for a streamer).

Recovery:
Excellent Kevlar/elastic combo. The 12" chute is overkill though, resulting in long, slow decent. A streamer would work just fine on this lightweight rocket.

Flight Rating: 4 out of 5

Summary:
Excellent reproduction and a good value (the kit retails for $6, can usually be found around $5).

Overall Rating: 4 out of 5

Other Reviews

Semroc Javelin By Jay Goemmer
Brief: The single-stage 4FNC Centuri Javelin was my very first model rocket, as seen in this photo of myself from the early 1970's. Estes model rockets were only available by mail order in South-Central Idaho back then, but I could easily buy Centuri model rockets at a drug store in my home town of Jerome and a hobby shop in nearby Twin Falls. After coming back to model rocketry ...

Flights

Comments:

S.E.J. (August 2, 2004)

I wish I'd thought of that paint pattern when I finished my Javelin. The red and black fins look snazzy. Bummer about losing it; I would like to try my Javelin on a C6-7 someday, but might switch to a nice long streamer first! I have been using those free address labels that charities send out as rocket labels. I put them on the nose cone shoulder, where they are visible only after ejection.

J.G. (October 22, 2004)

After losing my first Semroc Javelin on a "C" motor, I have to agree with Stefan E. Jones and Chan Stevens that this *very* lightweight rocket would recover just fine by substituting a streamer for the 12" parachute (regardless if I *was* overcome by nostalgia about the yellow and black 'chute), even on "A" or "B" 18mm motors.

B.B. (May 25, 2005)

On the topic of a parachute or streamer, back in the old days, the Javelin was an extremely common model and everybody I knew had 3-4 of them. We quickly learned to use either a small streamer (like 24x1 crepe paper) or nose-blow recovery. A 12" chute is WAY too much for sport flying. There were a lot of PD contests won in my area using a box-stock Javelin with the stock 12" chute. A 3-fin version also worked great for B Altitude (long before the existence of 1/2" or 10 mm motors, of course).

Post a Comment