M27 flying wing – build thread

I decided to apply some of the lessons learned from my Papa Divine wing (chiefly: big, fat airfoils on a flying wing are a bad idea) to a rebuild of my mediocre night wing, the M226M226

All the guts will be moving over to the new plane:

  • 1300 kV ‘Blue Wonder’ 24 gram motor
  • 20A ESC from Heads Up
  • Two (2) 10 gram HobbyKing servos
  • 850 mAh 3-cell LiPo batteries
  • OrangeRx R610 receiver
  • 48 white LEDs

Here are the plans for the new wing. The dimensions are based on my P115 flying wing, one of my all-time favorites, but the airfoil and construction will be completely different.

plansThe four wing skin panels that will make up the outer skin. I’m using Readiboard / Dollar Tree foamboard.4-wing-skinsThe airfoil is a close approximation of the MH-60 airfoil. I pulled the shape into Photoshop and put a line around the inside representing the approximately 0.20″ thickness of the naked Readiboard. When I cut out the ribs, I cut inside of this line. The idea is the foam will ‘fill out’ the airfoil to the correct dimensions.airfoil-template airfoil-ribsFiguring out where the motor, battery, and propeller are going to go.floor-and-prop-fitGluing two wing halves together to form the bottom of the wing.glue-wing-halvesCutting out the prop slot.cutting-prop-slotI glued 3/8″ balsa to the leading edge of the wing. I glue it point down, so it’s a diamond, rather than a square, when seen in profile. I sanded an angle in the foamboard to help accommodate it.glue-leading-edge-sparGluing in the ribs. I made a couple of little measuring tools from foamboard to help keep everything properly spaced and more-or-less square. (The wing ribs are 3.75″ apart.)gluing-ribsAll the ribs started. Since the bottom of the airfoil is curved rather than flat, I started by gluing the front of each rib in place. You can see that the backs of the ribs are sticking up in the air slightly.ribs-in-placeHere are the ribs, glued down all the way to the back. leading-edge-2I stole this ‘floor’ piece from the other wing. That wing used a flat-bottomed airfoil, which this wing doesn’t. I didn’t want the wood to force the bottom to be flat, so I steamed it and bent it to give it a curve matching the bottom of the airfoil. bend-floor bend-floor-2Getting ready to glue the floor piece down to the foam. The two black zip ties will help support the motor mount. You can see a little wooded ramp toward the back. This is to compensate for the shape of the airfoil which would otherwise tilt the motor up at an angle.floor-and-motor-mountThe M226 was a night flyer. I stole its lights and batteries to transplant into this plane.mounting-lightsWith the lights in place, I can glue the top skin in place.upper-skinBoth top wing skins in place. The plane is really taking shape.top-skins-in-placeUsing some T pins to hold the skin in place against the balsa leading edge spar until the glue sets.pins-in-top-skinRounding off the leading edge.rounded-leading-edgeStarting the process of covering the plane in Dollar Tree cellophane wrap. I glue it in place with 3M Super 77 spray adhesive, then shrink it drum tight with a heat gun.cover-1-wingI didn’t expect the plane to come out so pink; the cellophane looks red on the roll.cover-top-wingTesting the LED lights. I moved the elevons over from the old wing.light-test-top light-test-bottomSome simple winglets.wingletsLast but not least, we’ll need a battery hatch. I cut out a simple shape.hatch-blankTape it in place at the front with fiber-reinforced tape. I use a little more packing tape to cover the white tape up.tape-hatchFor a hatch clasp, I epoxied a magnet to a little piece of balsa glued under the foam in the rear. I epoxied a corresponding magnet into the foam of the battery hatch above.hatch-magnetHere’s the more-or-less finished wing. top-assembled

AUW: 336 grams / 11.8 ounces

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