Brief:
This is a 3x18mm cluster, vectored-thrust, single stage.

Construction:
Parts List:

• 1 BT-55 (18")
• 1 BT-60 (18")
• 3 BT-20 (2.75")
• 1 Balsa nose cone (5 3/8" straight cone)
• 1 Balsa transition (1")
• 3 Sheets balsa fin stock (1/8")
• 1 Sheet balsa fin stock (1/16")
• 1 Custom laser-cut centering ring
• 1 Wide shock cord
• 1 Plastic 16" parachute kit (unassembled)
• 1 Screw eye (medium)
• 2 Launch Lugs (3/16")
• 3 18mm engine blocks
• 1 Fin Pattern Sheet
• Assembly instructions, including hints and tips for clustering

All parts were included and arrived in very good condition.

The instructions were extremely easy to follow, and were very extensive. Pictures were provided for every step of construction, with multiple images within each figure for more complicated steps.

The motor mount assembly was clearly presented, which was essential for such an unorthodox mounting configuration. The motor mount assembly was actually quite simple, and produced a surprisingly strong structure.

The main body tube was prepared by using the fin marking guide, which included cut-out areas for the motor mount tubes. The notches for the motor tubes are cut out, and the motor mount assembly slides up into the notches. The instructions direct the builder to sand the notches with a piece of sandpaper wrapped around a spent motor casing until the assembly fits snugly into the end of the body tube with the centering ring flush with the tube end. I had to sand off an additional 3/16" before I was able to get the mount to fit properly, but once it did, gluing was easy and the mount fit perfectly.

Each of the fins consists of a main fin and a strake. The instructions again are very clear about how to ensure that the wood grain is properly aligned for maximum strength. Because the forward edges of the main fins are angled, the trailing edge of the strake must make an equal angle, which may prove difficult if the angle had been altered slightly during the sanding process. Once the two wood pieces are matched, they join easily. The main fins are attached first, and then the strakes are attached along the guide lines drawn earlier with the fin marking guide.

All parts are extremely well made, and fit together very well.

Pros:
Very thorough instructions
Strong airframe

Cons:
Engine mount notches not cut deep enough
Fin/Strake alignment may prove problematic

Finishing:
No special requirements or techniques are mentioned for the finishing of this kit. For those who desire to replicate the images on the cover of the packaging, a masking template is provided for the numeral "3". No decals are provided.

Construction Rating: 4 out of 5

Flight:
The kit packaging recommends either B6-4's or C6-5's, as long as you use 3 of the same kind.

I launched mine on C6-5's, and for the first two flights, only two of the three motors ignited, due to a faulty clip-whip. Despite the loss of thrust, the rocket still flew beautifully and the ejection was well timed. Once I was able to get all 3 to light, it flew even more beautifully than I could imagine. It truly was amazing.

Recovery:
The only problem I have with the flight was the recovery system. It utilizes a paper tri-fold for securing an elastic strap to the inside of the body tube. The parachute itself is also a thin plastic and uses cotton threads for shrouds. This system, while simple, has also proven problematic in the past over repeated launches.

Pros:
Outstanding design, even on a failed motor
Beautiful flights

Cons:
Recovery system could be more robust

Flight Rating: 4 out of 5

Summary:
This rocket is an outstanding introduction into the enjoyment of clustering. It is designed so well that even when only 2 of 3 motors ignite, it still flies straight! The construction is very well guided through copious illustrations.

The Tres will inspire wide-eyed stares from onlookers as you walk it to the launch pad, and will evoke ooh's, ahh's and wow's once airborne. A definite must for any rocket collection.

Overall Rating: 4 out of 5