Brief:
A fairly accurate single-staged scale representation of the Starchaser Industries' Thunderstar (their entry in the Ansari X-Prize competition) that uses a two-engine cluster like the real rocket was planned to.

Construction:
The rocket kit consisted of a white BT-60 body tube for the main airframe, a dual 18mm motor mount (consisting of two fairly thin centering rings, two 4" long motor mount tubes, two motor retainer hooks, two engine block rings, and two mylar retainer rings), a plastic nose cone, a laser-cut sheet of balsa fins, a mylar/paper launch lug, a yellow spacer tool tube, a 1/4" wide rubber band for the shock cord, a preassembled 18" plastic parachute, and a bag full of plastic detailing parts. All the parts were present in my kit. None were damaged though some of the longer thinner plastic detail parts had slight warps in them which disappeared when they were glued in place.

The instructions were typical Estes fare: well written and illustrated and in a fairly logical order. Plastic parts were not on molding sprues, they had been cut off at the factory. That was a courtesy I wish they hadn't done when it came to the tiny escape-tower nozzles because I kept dropping the fool things.

Only one minor "gotcha": the dual mount centering rings are prone to breaking in half at their outside edges. I filleted the area between the tubes heavily with Elmer's gel School Glue to prevent any ejection-gas leakage.

I used a 48" section of 3/4" x 3/4" aluminum angle for a straightedge to extend the wrap-around guide lines the length of the tube. This works as well as the old door frame as well as on tubes that wouldn't fit in the frame too.

I wasn't all that impressed with the laser-cut fins. They weren't any easier to work with than die-cut fins would have been. I attached them with CA then filleted with the Elmer's gel.

I added a 28" black shoelace to the end of the rubber band shock cord Estes provided--cheap insurance against denting the tube.

PROs: Nice plastic parts, good overall materials

CONs: Flimsy centering rings and typical short shock cord.

Finishing:
Finish for the balsa parts was two coats of Testor's Non-toxic Cement for plastic models to seal the grain. This was the first time to do this on a model rocket, but I do it all the time on static models and it gives a nice smooth finish with no sanding between coats. I painted the base coat white with Liquicolor Artists Acrylics. (It was too grungy a day to spray paint.) Then used model enamel from Testor's for the silver on the nose cone and black on the display base with its nozzles.It was a simple paint scheme that anybody with a few rockets in their fleet could do this one without any fuss. I wish the kit would have used waterslide decals instead, but that's just my personal preference.

It looks really great on my display shelf between my Aerotech Warthog and my CC Express with its expanded payload-section modification.

Construction Rating: 4 ½ out of 5

Flight:
My flight testing was at the AARG launch at the Hutto Hippodrome in beautiful rural Central Texas. It needed eight squares of fireproof tissue as wadding for each of three flights. I loaded two Estes B4-4 motors for its maiden flight, since there wasn't any significant wind. I used the stock 18" parachute included in the kit. The club set me up on a multiple launcher powered by a 12-volt deep-cycle battery. I had a very nice straight flight, which was tracked to 575 feet (using the single theodolite triangulation method). Not bad for my first cluster bird in over fifteen years...

Second flight was two B6-4s. Once again, a very nice straight boost with ejection just after apogee, which was 700 feet at that point according to the guy with the calculator. A little more drift than I liked on this flight, I probably need to switch to a 12" chute for my next flight, since I'm going for broke with two C6-5s for that one.

Flight number three was with two C6-5s and a 12" chute to 890 feet! Not bad at all for a scale model.

Recovery:
The Thunderstar uses the folded paper Estes shock cord fastener and rubber band shock cord, to which I added a 28" black shoelace for cheap insurance against the notorious "Estes dent" effect caused by their too short shock cords. It went together well.

There was no damage and the recovery speed was about right. I used a 12" chute for my flight on C6-5s. It came down closer to the pad on that flight and almost too fast.

Flight Rating: 4 ½ out of 5

Summary:
Main PROs: nice plastic detailing parts, well-planned use of a 2-motor cluster to represent a 2-motor prototype, headline-grabbing subject.

Only CON: flimsy centering rings on motor mount.

Overall Rating: 4 ½ out of 5

Brief:
This is a scale model of the Starchaser Industry's entry in the Ansari X-Prize. Just like the real Thunderstar, this model is a cluster kit. It has a two engine cluster mount that flies on 18mm motors. It's a beautiful scale model and a good first cluster rocket.

Construction:
The kit comes with the following parts:

• 2 18mm engine mount tubes
• 1 body tube
• 1 spacer tool for construction
• 2 mylar retainer rings
• 2 engine blocks
• 1 nose cone
• 4 laser cut balsa fins
• 1 1/8" launch lug
• 2 engine hooks
• 1 rubber shock cord
• 2 die but centering rings
• 1 18" parachute
• 1 decal sheet
• many plastic parts to form the escape tower, conduits, and the display nozzle base for the scale model

The fins are strong balsa wood that are laser cut into a balsa sheet. You still have to use a hobby knife to cut them out of the sheet but it is not difficult at all to do. The centering rings are made out of thin cardboard, however, and are rather flimsy. They bend easily, especially where the holes for the motor tubes are close together and the centering ring is thinnest. The motor mount tubes are 4 inches long and handle 18mm engines. There are two of them though, since this is a cluster rocket. The shock cord mount that comes with the kit is standard Estes tri-fold paper shock cord mount. It has a rubber shock cord, but the shock cord is 30" long so it works very well. The nose cone is molded plastic and shaped like the capsule of the actual craft. It is suppressed on the front for the escape tower to be glued to the top of it. It has fine scale plastic parts that are molded for this rocket.

The instructions are easy to follow with good diagrams, although I do not typically go it exactly the same order as they are listed.

The weakest points in the kit were the flimsy centering rings and the shock cord attachment. The motor mount tubes fit into the centering rings rather easily and I used Titebond glue to attach them. I used plenty of glue to make up for the flimsiness of the centering rings. Just be sure when the glue is setting that you do not twist any of the motor tubes. They seem to twist easily and this would causes the rocket to spin undesirably during thrust. And instead of using the tri-fold shock cord mount that came with this kit, I built my own shock cord mount. I thought that the Estes' mount may not hold up to many dual ejection charges. I used 90lb test Kevlar® thread and made sometime similar to a mini version of the LOC/Precision shock cord mount. I tied knots in the ends of the thread and covered them in epoxy. Then I tied the shock cord onto the loop in the thread. I'm sure this will hold together fine and last many flights.

All of the parts fit together very nicely, although the plastic parts for the escape tower may be slightly difficult to hold together while the glue sets. I rigged up a jig with some scrap wood and rubber bands to hold the two halves of the tower together while the glue dried, but once you get it all together the plastic parts look awesome.

PROs: Easy Estes instructions, Good fitting parts

CONs: Estes shock cord mount, Flimsy centering rings

Finishing:
This kit is a scale model and came with decals and a paint scheme to make it look very similar to the real thing. I first primed everything with a flat white paint. Then I sanded down and smoothed everything out. Then I added another coat of white paint (seeing how the model is supposed to be white in the end anyway). I sanded a bit and added a final coat. I took the display nozzle off during this point and just painted it black. I then applied the decals to the rocket. I liked these decals. They are just adhesive decals, not waterslides. I find them very easy to work with just as long as you are careful not to place them in the wrong spot. I would actually prefer these decals over waterslide ones. After putting on the decals I added a final clear glossy sealer coat. With the decals and glossy finish, this turned out to be one sharp looking scale model.

PROs: Adhesive decals, good looking scale model

CONs: None

Construction Rating: 4 out of 5

Flight:
The recommended motors are: two A8-3s, two B4-4s, two B6-4s, and two C6-5s. Prepping this rocket is just as easy as any other Estes kit. The only difference is that there are two engines to prep instead of only one. After placing the igniters and plugs in the engines the instructions say to twist the leads of the igniters together to light them with one pair of alligator clips. I have a five engine clip whip and chose to use that to ignite the cluster instead of twisting the igniters together. I placed 4 sheets of recovery wadding into the airframe tube prior to flight to be sure that the parachute or shock cord would not get charred from the dual ejection charge.

For my first flight of this scale cluster model, I chose to use two A8-3s. I was launching at the local club meet and this was my first cluster so I wanted to be sure that nothing went wrong with it by overpowering it the first time. Both engines ignited perfectly with the use of my clip whip and it took off. It coasted up and slowed to apogee. The ejection charge fired at the 18" chute deployed. It was not a very long flight, as I heard one of the club members say "Short and sweet." But it was a good looking flight to me.

PROs: Good first cluster, Looks great taking off the pad

CONs: None

Recovery:
The 30" long shock cord does the trick in this kit and the 18" parachute brings it down nice and soft. It was easy to assemble the recovery system even with the modification to the shock cord mount.

The recovery system deployed right at apogee and the parachute perfectly unfurled. I think that the descent speed was perfect for this rocket. It was nice as soft so that nothing even had the possibility to be damaged. The 4 squares of wadding did the trick because there was absolutely no evidence on the shock cord or parachute that there had been any hot gases to deploy them at all. They still looked brand new.

PROs: Great speed on decent, No damage or wear with the right amount of wadding.

CONs: None.

Flight Rating: 5 out of 5

Summary:
This is a fantastic rocket for the scale enthusiast, the cluster lover, or anyone interested in either one of these types of model rocketry. It is a good solid kit and may have a few areas where improvements could me made, but with a little construction technique, these shortfalls can be overcome. I would recommend this kit to everyone seeing how I absolutely enjoyed building it and especially watching it take off on those two engines. This was my first cluster rocket and I can now say that I am hooked.

Overall Rating: 4 ½ out of 5