Brief:
This review describes my second-generation Micro-Maxx monocopter. The improvements over my original include a lighter wing, a smaller motor pod, and a carbon rod balance beam. It has undergone numerous minor tweaks and one major revision. The maximum altitude obtained to date is about 9 feet.

Construction:

• Materials
• 3/16” balsa for wing and hub (see diagram)
• wrapping tissue paper
• white puzzle glue (pre-thinned white glue)
• ink tube from BiC pen (1/2” used)
• 0.03” carbon rod (7” long in final configuration)
• scrap paper to roll motor tube
• ¼” dowel for nose cone
• black CA

Please refer to the figures while reading the construction notes.

Wing - Make this out of 3/16” balsa as indicated, with the grain oriented with the leading edge. I removed sections to make it lighter and sanded it into an airfoil shape. The entire wing is covered with wrapping tissue attached with puzzle glue. I made it out of a scrap piece of wood, hence the odd shape. My thanks to John McCoy of NARHAMS for suggesting this construction method.

Hub - This, too, is made from 3/16” balsa. The grain should probably also be along the leading edge, although it was perpendicular on my model. I rounded both the leading and trailing edges. I drilled a hole at the lateral CG and installed a half-inch section of ink tubing. This is flush with the top surface and extends below the hub.

Motor tube - This was rolled from drafting vellum and white glue. It is about 1/8” longer than a MMX motor.

Nose cone - This was turned from a ¼” dowel on a hand drill.

Balance beam - I started out using 3/32” wood of varying length (see flight log table). I replaced it with 0.03” carbon rod, which was graciously supplied by John. The wood dowel was simply glued to the bottom of the hub next to the launch lug, while the carbon rod was inserted through the balsa hub.

Assembly - All components were glued together with black CA. The wing and motor tubes are centered on the hub and are angled upwards away from one another. The wing is angled at approximately 12 degrees, and the motor pod at approximately 15 degrees.

Flight: All flights were from my MMX pad with a 1/2” long launch rod. The igniters were Estes and the MMX ones with the plastic shell removed. For all but flight #10, I used my Pratt GO Box. The wind was calm except for flight 10, which was 5 - 10 mph in my guestimate.

Summary:
I was pleasantly surprised with the performance of this monocopter, considering the short burn time and low thrust of a Micro-Maxx motor. On my next version, I will make the wing slightly longer (for hopefully even better performance), and will use a rectangular shape with a slightly rounded tip (for aesthetics).