Friday, January 21, 2011

Review: Art Applewhite - Stealth D5 (Beta)

This was a Beta test version Art’s popular Stealth Qubit that was specifically designed exclusively for the new Quest D5-P 20mm diameter, long burn motor. The motor's long burn and thin wall, combined with a lot of spinning, led to questionable flight profiles and even a case burn through. As a result, this kit was never released to production. (That's why you test!) I offer it mostly as a caution for the users of these motors.



Construction:
The kit included two sheets of heavy cardstock. The design is available in several colors, but I opted for plain white so that I could paint it black (black is currently not available). Materials required include white glue, an X-Acto hobby knife, a metal ruler, sharp scissors, and a ball point pen.

This kit it very similar to the 18mm Stealth. However, since the D5’s are plugged the top does not need to be open to accommodate an ejection charge. Printed on the card stock are three components: a top section, a bottom section, and a triangular motor mount. Construction is typical cardstock. You cut the solid lines, score and fold the dotted ones, etc. Make sure you dry fit the parts and that the launch lug hole are cut out and aligned.

Finishing:
I shot the top with Rustoleum flat black and the bottom with Rustoleum day-glo orange.

Flight:
There wasn’t much prep since the D5’s are plugged. My motor mount was snug enough that I didn’t even need tape to friction fit the motor. The Q2 igniter is inserted and taped to the base of the motor.

I flew this three times. On the first flight, it left the pad fast and quickly began to arch over. The altitude was still respectable and the burn is long.





On the second flight, it had a wicked spin with an audible 'whirrrrrr'. The wicked spin caused the motor to burn through near its base, similar to what is seen on a monocopter. This deposited residue on the opposing fin but did not burn it.

The third flight also arced and spun, but this time it headed down under power.

Summary:
I like the long burn and spin and the burn-through wasn't too troublesome. However, the power dive was bad. As a result, Art never produced kits for this motor. While the D5-P sounds promising for saucers and monocopters, you should be aware of the issues identified in these test flights.