Have fun, nevertheless!

Transcription

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2 Nanomum The Nanomum is a small pusher gyro for flying indoors or outdoors in very calm weather. It's got a dc head and is easy to build and easy to fly - I hope. Specs: AUW 70 g / 2.5 oz. Rotor diameter: 560 mm / 22" Motor: 9 g kv Prop: GWS 4.5 x 3 Rx: GWS R4P/JST Servos: Blue Arrow, 3.5 g ESC: YGE 4-BL Battery: AHA 2s-200 mah As usual, the plans come in two versions, a jpg-version for looking at and a pdf-version for printing. If you print the pdf-files without any size adjustment, they should print to scale. Start with the fuselage. Print out the fuselage.pdf file and use the drawing as a template for cutting the outer contour of the fuselage. Use UHU por to glue a 3 x 0.3 mm / 0.12 x 0.025" cf strip around the fuse's outer edge. Then cut out the openings for the motor and servo tray using the same drawing. Use UHU por again to glue a 3 x 0.13 mm / 0.12 x 0.005" cf strip of about 360 mm / 14" lenght to the inside the motor/prop cut-out to reinforce it. Cut the servo tray (parts.pdf) from 0.8 mm / 0.03" ply and glue it to the fuse. Cut the landing gear supports and elevator fins from 3 mm Depron (parts.pdf). Paint everything. If you are using a motor like mine - and I suppose you will be, because its one of those universal chinese motors that crop up everywhere - use a 20 mm / 0.8" long piece of cf tube with an I.D. of 6 mm and an O.D. of 8 mm to mount the motor. Make a 2 mm / 0.08" deep cut-out around some 40% of the perimeter of the tube at the motor end to protect the leads coming out of the motor, then epoyx the cf tube into the fuse with the cut-out facing downwards. Make a 3 mm / 2.76" hole for the landing gear and glue a 70 mm / 2.76" piece of the ubiquitous outer bowden cable tube into that hole. I've used silicone for that connection to keep it elastic. Use UHU por to glue the landing gear supports and elevator fins to the fuse. Put a 1.5 mm / 0.06" cf rod of 200 mm / 8" length into the bowden cable tube and secure it with pieces of adhesive tape taped around the rod. The wheels you use should be very light, something about 1 to 2 grams. Build yourself a Micro Hinge as described here: The distance from the lower end of the 2 mm cf rod to the hinge point is 75 mm / 3", the length of the control arms is 35 mm / 1.38" and the angle between the control arms should be around 60. Glue the Micro hinge to the right side of the fuse with silicone. While you're at it, reinforce the epoxy joints of the motor mount by filling out the notches with some silicone too. Use double sided adhesive tape to fix the servos to the servo tray. Click mini push rod connectors (Multiplex # , something similar to the Du-Bro RC Mini E/Z Connectors) into the outermost hole of the servo arms. Use two 150 mm / 6" long pieces of 1 mm / 0.04" cf rod as push rods. Slide two 35 mm / 1.38" long pieces of thin heat shirink tube about 15 mm / 0.6" over the ends of the control arms and provisionally

3 shrink thight at the ends of the tube. Stick the push rods into the other end of the heat shrink tube until they connect with the control arms, bend them down and shrink everything tight. Provisionally fix the push rods in the connectors. Mount the motor with its prop, the Rx and the ESC at the positions shown in the plans. Don't mount the battery yet, we'll use that to adjust the c.g. later. What's left is the rotor. This is a three-bladed modification of Al Foot's Monotwirl rotor (rotor.pdf). The central part of the hub is a triangle sandwich with a side length of 27 mm / 1.063", made of 3 mm / 0.118" layers of ply, balsa and ply. The hole in the middle should be large enough to take a ball bearing with an I.D. of 2 mm. Soak the outer surfaces of the triangle with thin ca glue to make them more resistant. Cut the three blades (35 x 270 mm / 1.4 x 10.6") from 3 mm Depron. Reinforce the leading edges with 3 x 3 mm / x 0.118" balsa strips and glue the 1 mm balsa triangles to the bottom of the inner corners at the trailing edge. Sand some chamfers to the inner blade edges as shown in the plan. Round off the leading edge. Cut out the two top and bottom circular blade stops from 3 mm Depron and paint the blades and blade stops. Put a small mark on the top of the blades at the inner edge, 6 mm / 0.24" from the leading edge. Put ropes of UHU por diagonally upwards in a clockwise direction across one side of the triangle and on the inner edge of one of the blades. Wait for the glue to get dry, then place the leading edge of another blade against the side of the triangle that is behind the upper end of the UHU por rope. Now take the glue covered blade, put its trailing edge on the 'other' blade and its leading edge on the surface of your workbench, align the mark on top of the blade with the edge of the triangle and push the blade against the hub triangle. Do the same thing with the other two blades - well, nearly the same with the last one. Then gently lift the trailind edges of the blades and put a small drop of UHU por into the blades overlaps, just a small one to hold them together. Now glue the top and bottom blade stops to the top and bottom sides of the triangle - and to the triangle only, not to the blades. Press the ball bearings into the center hub hole and put the rotor on the rotor mast. Add a washer and secure everything with a wheel collar - preferably an aluminium one - or some heat shrink tube. If you have a good idea how to mount the front wheel, then do it now. My Nanomum has no front wheel yet, I'm still afraid it will simpy get ripped of when I touch down in the relativly high grass at our field. But good ideas for a front wheel mount will be appreciated. Place a mark on the right hand side of the fuse where the c.g. is supposed to be. Put the flat head of a socket head screw over the mark. Hold the screw between thumb and middle finger and put your forefinger through the prop cut-out on top of the Depron above the screw head. With your other hand you can now push the battery around on the fuse. Lift your forefinger slightly and you can see which direction you should move the battery. When everything is balanced, fix the battery. Now for the set-up. The movable part of the rotor axis shoiuld be tilted some 10 forward, compared to the fixed part. To obtain a straight descend during autorotation - that is with the motor off - the rotor should be tilted some 14 (fouteen degrees, its true, that's what coning does to you) to the left, seen from behind. At full speed the tilt should be reduced to some 10. When you're launching the Nanomum, use only 2/3 of full power. The 9 g motor I'm using is a bit oversized for the Nanomum, and you have to be careful if you apply full power. Do your first flights indoors or in a near dead calm or she will be gone with the wind. Otherwise she's quite a normal gyro to fly, though I've had some crazy situations. Once, after test flying the Nanomum v2 - still very secret -, I forgot to set the Tx set-up back to Nanomum v1. I launched v1 and she turned right over on her back. The rotor stopped, but that did not keep her from flying straight on. After a few meters I decided

4 to put an end to this madness and turned the motor off. Which caused her to gently glide to the ground and land safely on her rotor. Since then I've got the sneaking feeling that we are making some fundamental mistake when we're tryind to get these rotors to rotate properly. Have fun, nevertheless!

5 200 mm 8 ESC 100 mm 4 Rx Batt. 200 mm 100 mm 8 4 0

6 150 mm 6 flat cf rod, 3 mm x 0.3 mm fuselage, 3 mm Depron 100 mm 4 flat cf rod, 3 mm x 0.13 mm flat cf rod, 3 mm x 0.3 mm 200 mm 100 mm 8 4 0

7 5 x EPP, 3 mm 150 mm 6 cf, 0.13 x 3 mm 1 x 100 mm 4 2 x 2 x cf, 0.25 mm 2 x 2 x cf, 0.6 x 3 mm 200 mm 100 mm 8 4 0

8 landing gear supports, 3 mm EPP elevator fins, 3 mm Depron servo tray, 0.8 mm plywood landing gear, outer bowden cable tube landing gear, 1.5 mm cf rod push rods, 1 mm cf rod control arm, 1.5 mm cf rod rotor mast, 2 mm cf rod

9 top hub cover, 3 mm Depron spacer, 0.8 mm plywood inner blade end detail hub top, 2.5 mm plywood hub middle, 2 mm balsa hub bottom, 2.5 mm plywood 150 mm 6 3 mm Depron 0.25 mm cf reinforcement balsa, 3 x 5 mm cf rod, 2 mm bottom hub cover, 3 mm Depron leading edge reinforcement, 3 mm balsa hole for 2 mm ball bearing 100 mm 4 blade, 3 mm Depron 270 top and bottom hub cover spacer 200 mm 100 mm top and bottom blade reinforcements 8 4 0