Balsa Machining Service School Rocket

Balsa Machining Service - School Rocket {Kit}

Contributed by Geof Givens

Construction Rating: starstarstarstarstar
Flight Rating: starstarstarstarstar
Overall Rating: starstarstarstarstar
Manufacturer: Balsa Machining Service
BMS School Rocket BMS School Rocket

Brief:
The BMS School Rocket is a small, traditional 4-fin rocket. BMS is a good low-power parts supplier for scratch builders. This the first time I built a pre-packaged kit from them. It is 14" long with BT-50 airframe and 18mm motor mount, weighing only about 1 1/2oz finished, much of which was extra nose weight we added (see below). My daughter and I built this kit together.

Construction and Finishing:
This kit is absolutely fantastic. And that opinion is coming from an experienced L1 flier with hundreds of flights, scores of rockets, and dozens of scratch builds ranging from a 7lb I-motor to 4-foot wingspan boost glider, and also from a young girl. At both ends of the range of experience we found things to love about this little rocket.

What makes this kit so great is its elegant simplicity. The instructions are given on 2 two-sided printed pages. The language is very clear with plain simple wording and ample photos: one for each step (19 in all!)

Construction begins with the motor mount. The motor tube has a pre-punched hole for the Kevlar® shock cord to pass through. It also loops around the engine stop block in a unique way. One of my few complaints arises here: the instructions are helpfully laden with photos but the print quality is rather poor. For this step with the Kevlar® and engine block, I couldn't discern from the photo exactly how the knot and looping were supposed to work. After discussing this with my daughter, we figured it out.

Next the centering rings are installed. In a stroke of inspiration, BMS actually laser etched positioning rings on the motor tube so you can see exactly where to place the rings. You simply slide the rings to the indicated positions and glue. My only other complaint about the kit is that no engine hook was provided. We installed one anyway.

Managing the shock cord during the gluing phase here is important, and BMS had the forethought to ask that the screw eye be tied on before this stage. This allowed us to easily flip the cord through the motor tube as instructed to avoid getting the Kevlar® tangled in glue.

The tube is slotted so the laser-cut balsa fins slide right in. The balsa nose cone had a very nice snug fit and is ready for the screw eye. As usual, we forgot about the launch lug until after painting and glued it on afterward. Recovery is by wide, bright blue mylar streamer, but we swapped it out for a small chute to compensate for our extra weight (see below).

Now it is important to mention something very important about the photo. My daughter wanted to make something more creative than a standard 4FNC rocket so she designed an alternative use of the fins. She decided to use the "wrong" root edge and then to surface mount them between the slots. She also painted the motor tube red and installed it last to create the effect of a glowing interior "radiator tube" beneath the surface of the airframe. The new fin orientation required some nose weight to maintain stability.

Therefore, the photo of my daughter's rocket is not the configuration that BMS intended. I have included an image of the correct configuration to clarify this.

Why do I love this rocket so much? It is beautifully planned for simple construction. It is virtually impossible to make a mistake. If you used only CA superglue, you could build the entire rocket in 15 minutes.

Finishing was straightforward. My daughter chose pink and silver (and the red radiator), naming the rocket "Watermelon Dart".

PROs: Just about everything.

CONs: Needs an engine hook.

Construction Rating: 5 out of 5

Flight and Recovery:
The first flight was at NCR's Oktoberfest on the Pawnee prairie. The recommended motor was A8-3, but we swung-tested it for C6-7. So, we loaded a B6-4 and let her rip. With the extra nose weight, our flight had a beautiful, smooth, satisfying ascent...not too fast to miss all the action. Ejection was perfect, nose up. There was not even a scratch upon recovery. We're moving to C6-7 next time.

There's no point waiting for more flights before writing this review. It is abundantly obvious this classic design will give you a steady, stable flier. You can have absolute confidence in that. I think you can fly this bird until somebody steps on it.

PROs: Great flier

CONs: Is streamer landing as good as chute? And can you give us some B and C motor recommendations?

Flight Rating: 5 out of 5

Summary:
From the name, I infer that BMS intends this rocket to be used for school classes and other kids' groups. At $10 per rocket, it is perhaps a bit more expensive than some other choices. However, considering the incredibly simple assembly where the parts are marked and cut to virtually preclude mistakes, and considering the excellent flight characteristics, I would certainly recommend the BMS School Rocket for kids' organizations.

Overall Rating: 5 out of 5

Other Reviews
  • Balsa Machining Service School Rocket By Bernard Cawley (October 11, 2009)

    Brief: The BMS School Rocket is a basic four fin and a nose cone streamer recovery beginner rocket that is well thought out and well executed. It has a few interesting features including through-the-wall fin mounting for extra ruggedness and laser etched lines to tell you where to put the centering rings on the motor mount and the launch lug on the body. It's a little larger and ...

Flights

Comments:

avatar
M.G. (March 28, 2009)
Ten bucks is kind of high however, but mine came with a streamer which I used along with a 12" chute kit. So for the price, you get a free chute plus I really like the TTW fins on a small rocket.
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L.D. (April 14, 2009)
I have used several hundred of these rockets for group builds with kids and have found them to be the easiest, most reliable to build and launch. The parts quality are second to none. The laser marks on motor mount and body tube and pre-cut slots for the through the wall fins make assembly easier for novices and make the launches straighter and predictable. The kit was always available with a motor hook and now it seems to be standard instead of an option. In bulk they are $5.25, or $6.25 with an A8-3 motor included. There are new instructions available which seem very clear and easy to follow. Also BMS provides excellent customer service!

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