Designed by Dick Sarpolus. Free plans from Winter 2014 Park Pilot.
The Akro can be built quickly and easily, and for a truly low cost. The model flies well, it’s big enough to handle some wind, and it’s great for basic aerobatics. If you’re past the basic trainer stage, I’d suggest it as an airplane you could use to learn how to do all that aerobatic stuff. If the stress level felt while flying is proportional to the cost of the airplane, you can relax in the knowledge that the basic materials cost of the airplane was less than $10. So, hey! Even if you fly it into the ground, it can usually be fixed with five-minute epoxy. You can’t feel that bad if you crash an airplane that’s so inexpensive and easy to build. This Akro has a 38-inch wingspan with roughly 330 square inches of area. It’s 32 inches long and weighs approximately 12 ounces without the battery. Any 100-150-watt brushless motor will be fine, and opt toward the higher number if you want to fly the crazy stuff. Any 3S LiPo battery from 1300-2200mAh will do the job, depending on how wild and how long you want to fly. The main goal for this project was to give you an easily built, truly low-cost flying machine for active, worry-free fun flying. Some of the pilots in my flying club are just past the basic-trainer stage, and are now using flat-plate foamie airplanes like this Akro to get more air time without worrying about crashing a more expensive model. We also have club members who know how to fly pretty well. A few of them use these foamies to explore. Getting into wilder aerobatic maneuvers isn’t so scary when an $8 airframe is all you risk. Read the entire build article inside the Winter 2014 issue of Park Pilot.
All of the Akro’s foam parts are cut from 1/4-inch or 5mm sheet foam. Other materials are 1/32-inch plywood (fuselage doublers), 1/8-inch plywood (firewall and braces), 1/16-inch plywood (control horns), 1/4 x 1/2-inch basswood (wing spars and fuselage stiffener).
Any low-cost motor in the 100-150-watt power range is suitable for the Akro. The motor is screwed to the plywood firewall, and the ESC is held securely by Du-Bro Hook & Loop Material.
Use a 1500-2200mAh LiPo. Hold it tight with a strap made from Du-Bro Hook & Loop Material.
If the stress level of flying an RC airplane is in direct proportion to the cost of its airframe, you’re bound to enjoy a stress-free, relaxing day at the field when you build and fly Dick Sarpolus’ low-cost Akro.
Click here to download your free Akro Build It Plans.
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