Brief: Single staged, but with the choice of being flown with two or four 29mm motors, specified as 2 G type or 4 F type. It has the fins attached wedge style between the four motor tubes, which extend below the main body tube.
Construction:The nose cone is hollow plastic, and the fins are precut plywood. The tubes are spiral wound kraft paper. The parachute is a lightweight pink nylon. Very bright and pleasing to me. The launch lug is wound paper too, and is able to accommodate a 1/2 inch launch rod, which is good for a rocket of this height and weight.
All the parts were there and in good shape. The instructions were clear. Any head scratching was due to my inexperience with a rocket with fin wedge attachment, but once I understood it, it was easy to do. Alignment of the fins was tricky, as I had to sight it carefully as they dried. But once it dried, the fit was good, and the model sturdy. I applied extra epoxy fillets for good measure, though.
The rocket has four fins, and they fit into the grooves between the motor tubes. The main body tube isn't slotted, because the fins are off the motor tubes, which extend two feet aft of the end of the main body tube. They stick out, you see. That wasn't intuitively obvious to me at first, as the instructions didn't actually have diagrams of this. I feared at first that I was missing a main body tube to make the total length of 62 inches, as the main tube and the nose cone only made about 40 inches length. But once I understood that the motor tubes extended the rocket's length, I had a "Eureka!" feeling. The tops of the motor tubes are affixed into the bottom of the main body tube. I had the option of making that mount removable, but chose to make it permanent for strength. I gather from the instructions that I could have then flown it as a shorter, single engine rocket, then. But the cluster intrigued me more.
Finishing:As to finishing, the nose cone needed to have its molding seams sanded, but that only took a few minutes. Actually, I've noticed that these noses don't bond paint as well as I'd like. Little impacts chip the paint off. So, I use primer basecoats to help there. And the end results are smoother and prettier. I filled the spirals with epoxy, to make transitions smoother, but left them uniformly indented as a point of style. It would have looked odd to me to fill then completely.
I finished it with cross sectional bands of bright colors of monokote and painted the fins and nose bright orange. This was something to see! The RSO joked and said that it wasn't easy to spot on the pad.
Construction Rating: 4 ½ out of 5
Flight: I flew it with two G 35-4W motors, and it flew noisily and straight. There were two visible flame trails. Everyone loved it. With the chosen delay, the chute deployed as the rocket arced over, which was just what I wanted. The chute supplied was bright pink, which went with my color scheme, and aided in visibility. I did need to plug and tape the two other motor tubes to prevent gas loss. I retained the engines using tape, making a thrust ring at the aft end of the engine with tape, too. I used standard wadding to protect the chute. I used standard wadding to protect the chute. Worm bedding works great and prevents scorching. To get around the worry about having only one engine ignite, I used a battery with 7 amp hours capability and electric matches for igniters.
Recovery:The shock cord is attached by a system I came up with to prevent zippering of the body tube. I used a 3 inch centering ring with a center hole of 54mm mounted 2 feet down from the top of the main tube, and a metal screw eye through the ring is bolted at the aft side and epoxied at the forward end. A one foot length of eighth inch Kevlar® cord is tied to the screw eye and made into a double loop, to which the 1/2 inch wide, 136 inch slack length elastic is tied. A further note about my idea of using the centering ring this way: It provided a surface for the chute to rest upon, and I maintain that along with wadding, the design might prevent scorching of my chutes.
The standard instructions say to mount the shock cord to a glued, multiply folded paper mounting on the inner wall of the body tube, which works fine, except that I read in Sport Rocketry that zippering of the body tube might occur this way. I've never had it happen, though.
The chute didn't come with spill holes, and I left it so. Its diameter is 28 1/2 inches. The shroud lines are braided nylon cord whose length after I tied them to the nose cone was 23 1/2 inches. As I said, the chute is hot pink/maroon, and is a nylon. It's not as heavy as a rip stop nylon, but that's good, as it billowed beautifully at apogee.
The recovery was just about right, with no damage to the rocket, and a graceful and colorful descent.
Flight Rating: 5 out of 5
Summary:I totally love this one. I have no real cons. As for pro's, I'll say that it's great for aspiring clusterers and experimentalists who really want to get noticed at launches. I can't wait to test it with four motors. The flame trail will be a real sight.
I'm tempted to try this with two H engines. Has anyone got any stories about daring this?
Overall Rating: 5 out of 5
It is a nice mid-high power rocket that makes you enjoy clustering The packaging was standard Loc plastic bag but it made it through the mail ok. The fins were hard to align because they just stuck in between the motor tubes. I did ok by using a square. Everything else went ok. The instructions were vague to me but that's ok I had a lot of fun figuring it out (no note of sarcasm). It was easy ...