Brief:
2 stage low power rocket. Sustainer is tube fin design

Construction:
The parts include:

• BT-55 sustainer and booster body tubes
• 6 Balsa fins for booster
• 6 Beveled tube fins for sustainer
• Balsa nose
• Cardboard coupler, centering rings and engine block
• 2 Mylar streamers

This was my first Squirrel Works kit, my first staged rocket, and my first based around 24mm motors, so I was prepared for possible problems.

I did not need to worry though as the instructions were clear and all parts fit snugly. I built this rocket stock except for the substitution of a purple streamer to match my color scheme. I used yellow glue for most of the construction and a drop of thin CA on the joint of each tube fin.

If you have big clumsy hands like mine you may struggle to apply the fillets in the smaller than average gaps around the six finned booster. I used a syringe applicator from Deluxe Materials to get my glue into the gaps and this produced excellent results.

Finishing:
The balsa nose cone sanded really well, I hardly needed to apply any sanding sealer to get a smooth surface and a painfully sharp point (with a hole in my finger to prove it!).

I could see that it would be very difficult to fill all the spirals inside the tube fins, so I decided just to sand down the primer coat and live with the lines. With the metallic paint I used, the spirals were hardly noticeable.

Painting was standard stuff and putting the waterslide decal on was a treat.

Construction Rating: 5 out of 5

Flight:
As C-11s were not available for the first flight, I flew the sustainer alone on a D12-5. The motor was friction fit and five sheets of Estes wadding was used. The flight was near perfect with straight boost (to approximately 1000ft according to the RSO). Deployment was near apogee, but only one of the streamers seemed to deploy. Descent was at a reasonable rate and recovery about 100ft down range. Upon inspection the supplied red streamer had melted through even though it was packed above my substituted purple one. There was no damage from the landing, but the whole body was bent and there was a crescent shaped hole in the nose. I seems that at ejection the nose cone bounced back and hit the launch lug, bending the rocket. Luckily the body tube was strong and the RSO declared that I could fly the Tuber again without repairs other than replacing the damaged streamer.

For the second flight, I followed the instructions and taped a D12-0 to a D12-7 and installed in the sustainer, then attached the booster section. The wind had picked up and I was concerned about weathercocking with the amount of fin this rocket carries, so we moved the pad slightly and as soon as a slight lull occurred, I launched it. Boost was straight with minimal weathercocking and only a slight kick at separation. The booster tumbled down beautifully to be recovered without any damage. The sustainer climbed out of sight but was spotted shortly after ejection. Both streamers deployed without a problem and the rocket was recovered from nearly the same spot as the initial flight.

The sustainer now awaits repairs to the body tube and nose cone.

Recovery:
Given that the second flight resulted in no further damage, I believe the accident with the nosecone hitting the streamer was a fluke and just bad luck. However, in two different rockets the supplied streamers have melted whereas the ones I substituted are damage free. This rocket is so strong that it would probably survive a fall from maximum altitude without damage but make sure you substitute a reflective streamer to allow for easier tracking.

Flight Rating: 4 out of 5

Summary:
I was impressed by the performance of the Tuber in flight and the ease of construction. Although I had never built a 2 stage rocket or attempted to use 24mm motors, everything came together flawlessly. The lack of available C-11s meant that I had to jump straight to D power, but this kit handles them well. If it had not been for the streamer problem I would have given this a rating of six.

Overall Rating: 4 out of 5