Brief:
Two stage sport model designed for 24mm motors with fins on booster and tube fins on upper stage.

Construction:
The kit contains:

• Long upper and shorter lower body tubes (BT-55 size)
• Balsa nose
• 6 laser cut tube fins (upper)
• 6 laser cut balsa fins (booster)
• Centering rings
• Tube coupler
• 2 engine blocks
• Elastic shock cord
• Screw eye
• 2 mylar streamers
• 3/16" launch lug
• Custom water slide decal

This is one of Squirrel Works "signature series" kits, which they put together from other rocketeers' submissions of successful and unique models.

Like all Squirrel Works kits, the instructions and construction are intended to be easy enough for a first time builder. They are simply written and contain ample illustrations.

The laser cut balsa fins are high quality, but the laser cut tubes are truly eye catching. I've never seen a kit with precut tube fins with such smooth angle cuts. Often when painted, there is a slight fuzziness around the cuts. Not so with these.

Being the same diameter as the body, the fit of the tube fins on the upper stage is extremely simple. The six balsa fins on the booster are more difficult but no more so than any other surface mount fins.

As a two stage model with body tubes larger than minimum diameter, it requires matched up motor mounts and a tube coupler for a proper fit and performance. This is a bit more complex than your average beginner 3FNC design, however, the design of this model and the instructions make building this challenging enough to be interesting but not so difficult as to present problems.

    Picture courtesy of Squirrel Works

Finishing:
Seal the balsa, primer everything, and paint as desired. As with any tumble recovery booster, a bright color is recommended so it doesn't get lost. (After all, we all tend to watch the rest of the flight rather than follow the booster down.) The waterslide decal has the model's name as well as the signature of the designer. A clear coat over the decal will help keep it in place for many flights.

Construction Rating: 5 out of 5

Flight:
The only booster recommended is D12-0. Upper stage motors are C11-5, C11-7, D12-5, and D12-7. Due to mated two stage design, no motor hook is used so only friction fitting the motors in place with masking tape is used. A motor block is used in the upper stage and in the aft of the booster to aid in separation at staging.

First flight was on a D12-5 with the upper stage only. Booster was straight and fast with ejection at apogee and normal recovery.

Second flight was with a D12-0 booster and E9-8 upper stage. No, this isn't among the recommended motors nor is it in the instructions. I just can't leave well enough along when there's a chance of using more power.

Due to high wind (15+ mph) on launch day, there was significant weathercocking but the flight was clearly stable. Staging was immediate at booster burnout with a clean break and no jerking into a different trajectory with booster ejection. The upper stage shot off on this trajectory arrow straight at extreme speed. Ejection was slightly before apogee (still climbing but clearly arcing) at around 2000', nearly out of sight. The streamer made it easily visible coming down. Had the flight been vertical I estimate it would have topped 2500'. It was recovered without damage approximately 1000' downrange.

Recovery:
Recovery is with two streamers connected directly to the shock cord. These are mylar, making them highly visible. Even on the heavier E9 motor these are adequate for a safe descent rate. The elastic shock cord is anchored with a tri-fold paper anchor. The one change I made to the recovery system was to use part of a brown paper bag for the anchor. No burning or damage was noted and flameproof cellulose wadding being used both times.

Flight Rating: 5 out of 5

Summary:
This model is an excellent introduction to staging. As with all Squirrel Works kits, it is high quality in both building and results.

The only CON I can think of is my own inability to get waterslide decals to work right. This one did apply acceptably but I had my usual troubles. This is not the fault of the design or the manufacture, only of my impatience and fat fingers.

Overall Rating: 5 out of 5