Melusine - 3D printed electric glider and FPV platform

Melusine - Twin tailed siren

Wingspan: 2320 mm
Length: 1290 mm (varies with length of nose cones and tail booms)
Weight: 1600-2400 g
The prototype weighs 2300 g as flown in the maiden video and has 200 g of nose weight due to using heavy 12x10 mm tail booms instead of 12x11 mm. Later builds have weighed as little as 1600 g with 0,3 mm walls and partial use of ColorFabb LW-PLA (with reinforcements).
Energy per minute: <1,44 Wh/minute in the most heavy first flight configuration. Long flight times are possible, even with EDF.

Control surface deflection:
Ailerons 12 mm down and 20 mm up.
Elevator: 20 mm up and down. 25% expo.

Balance: 70 mm from the root leading edge.

Safety warnings:

-The EDF or propeller is a very highly loaded assembly at high speed so it's important that you know what you are doing.
-Make sure the integrity of the printed impeller/propeller is good before trying to run it.
-Always wear protective glasses when test runnin the fan. Always protect your eyes.
-Do NOT run the fan at high power while holding in your hand.
-Keep your hands and any loose items away from the fan when running. It WILL shred your fingers if they get sucked in, and the suction force is very strong. If something gets sucked in it can damage the impeller and potentially shatter, throwing loose debris out.

My first 3D printable airplane. It's a twin tail pusher prop electric glider with interchangeable noses for FPV cameras, and optional tricycle landing gear with a steerable nose wheel. It also has 3D printable folding props.

I don't recommend it for beginners because it's too fast.

Stay under 600 W with the printed propellers. Always stay out of the line of the prop disc and be careful with them. If you don't know what you're doing, you can always buy some props to be safe. 45 mm diameter spinner will fit.

Videos:

White Jet V-tail version
Afternoon flying at Senja MFK. Red jet bird Melusine flights starts at 5:40 in the video
Evening video from August 2018
Video of the maiden flight
Video of a flight with landing gear
Carrying camera
Onboard video

Required hardware. The links are my affiliate links, which helps me fund future designs, but costs no extra for you:

-Assorted M3x12 to M3x30 screws and m3x5 and M3x12 grub screws. M4x30 mm screws for the main landing gear. Also neded are assorted M3 nuts with and without nyloc.
-Two 12x11x1000mm carbon tubes for the tail booms. Cut down to 670 mm
Alternatively 12x10 mm tubes can be used, but this will require about 200 g of nose weight to counter the extra weight. 12x11 is highly recommended.
-One 10x8x500 mm carbon fiber tube for the wing center section. Cut down to 440 mm
-One 8x6x1000 mm carbon fiber tube for the outer wing panels. Cut into two equal length pieces
-Three pieces of 2mm round carbon fiber rod for the elevator, horizontal stabilizer, ailerons and elevator pushrod.
-Adjustable pushrod connectors for the elevator pushrod
-Pushrods for the ailerons
-One 44x10 mm nose wheel if you don't want to print.
-Two 60 mm main wheels if you don't want to print them.

Electronics:
-4x 9g servos for the control surfaces and nose wheel
-Servo extensions. 2x 15 cm and four 60 cm
-600-700 kv motor with 5mm shaft and less than 39mm diameter. Mounting screws 25 or 19 mm apart
The prototype flies with a Hyperion Z3025-12 665kv outrunner.
-A larger outrunner can be mounted to the outside of the plane. a 45 mm motor will be the same diameter as the fuselage. Suggested motor:
https://hobbyking.com/en_us/4010-580kv-turnigy-multistar-22-pole-brushless-multi-rotor-motor-with-extra-long-leads.html?affiliate_code=BSFWYBUNYWDKXJN&_asc=1693960018
-The plane can also be flown using a brushed 540 or 550 size motor.
-Suitable ESC with BEC
-3S to 4S lipo weighing at least 400 g for balance

Assembly:

Use your maker skillz and airplane experience to assemble parts that aren't mentioned specifically here. ;) Or let me know what's unclear in the comments below.

Wing parts should be glued together end to end with CA. 20-30 mm lengths of 2 mm carbon rod can be used in the rectangular slot on each wing joint to strengthen the joint for extra impact resistance, which I recommend: https://files.cults3d.com/uploaders/12943812/illustration-file/04c3ad42-3576-4bb2-838d-772b5e326af3/Melusine19.jpg I recommend using thick ca in a couple of spots first to tack it together, and then apply thin CA to the joint when it's tacked together in the right place. Sand the joint while the CA is still wet to fill the joint with PLA dust. End to end CA glue joints like these are surpårisingly strong. They have proven strong enough to pull an incredibly small loop when an elevator servo went haywire and pushed beyond max elevator up. Each wing half should have one 8x6mm diameter and 500 mm long carbon tube glued in to act as joiner with the center section. Also use 4mm carbon fiber or bamboo as alignment pins in the root end of the long wing panels. Ailerons should be glued together with CA and a 2mm carbon should be used as a hinge pin. The wingtips can be glued onto the wings when the ailerons are in place. Take care not to glue the hinge pins so that the ailerons can't move.

I highly recommend building the flaps and programming them so that you can use "crow" for landings. This comfiguration puts the ailerons up and the flaps down which makes the plane fly very slow and easy for landing. It's a huge improvement over not using crow. I have my surfaces set up for ~45° in crow configuration, and have crow on a dial so that I can apply as much as I want. I usually just go full crow for landing.

The two wing root parts (Flapwingroot01 and Wingroot02) on each side of the fuselage should be glued together, and then glued oto the fuselage, taking care to align the parts and also install the flaps. The center 10x8 mm diameter and 440 mm long carbon tube which will work as a wing joiner tube for the outer wing panels. On the prototype I drilled 2,5 mm and threaded holes through the wing tubes, where you see a hole on the top of Wingroot02, when the wings were installed and use M3x12 grub screws to hold the wings on. This compromises the carbon spars a little, but it should be fine as this is not intended to be a hitliner. An alternative way to hold the wing panels on is to use tape around the joint. This is common with sailplanes.

Fuselage parts should be glued together with CA of your choice, and will self align due to overlapping joints. The nose cone of your choice should be installed with M4 screws.The battery hatch should be assembled with three M3 screws and will click in place on the fuselage by pressing forward and down on the rear end. The motor hatch will also click in place by pushing forward while pressing the rear end down.

I recommend building the plane with a V-tail as it's lighter and flies just as well in my experience. The V-tail parts replace all the Hstab and Vstab parts if a V-tail is chosen.

The three horizontal stabilizer parts should be glued together with CA, and have a 2 mm carbon fiber rod in the leading edge for added strength. I do not recommend glueing this rod in place if you intend to fly in the winter, because it will cause the stabilizer to warp with large temperature changes. Use M3 nuts and M3 coutnersunk screws to assemble the horizontal and vertical stabilizers. The elevator should be assembled with CA and a 2 mm carbon rod should be used as a hinge pin. The carbon hinge pin should only be glued in one side of the elevator, or the elevator will warp with temperature changes because PLA shrinks when it's cold and expands when it's hot, while carbon fiber rods do not.

The vertical stabilizers are one piece and only need two m3 grub screws to secure them to the 12x11 mm diameter and 770 mm length carbon fiber tail tubes. Ideally they should also be glued in place, but I prefer to use grub screws in case something breaks. Glue the 12x11x770 mm tail carbon fiber tubes into the wing center section parts with CA.

The elevator control pushrod should be made from a 2mm carbon rod and uses the parts "Rodsupport01" as guides inside the tail carbon tube at 160 mm intervals along the rod. This ensures slop free and lightweight control. Use Rodsupport02 if you plan on using 12x10 mm tail tubes instead of the recommended 12x11 mm tubes. The elevator servo should be installed into one of the root wing sides as shown in the pitcure called "Elevatorlinkage01".

The folding props fit 5mm motor shafts and need two M3x12 grub screws to secure them to the shaft after the two tension plates have been inserted. The spinner might need some filing to fit the plates. The shaft needs to have a flat spot. Use two M2x30 mm screws and nyloc nuts to hold the blades between the two tension plates. The blades should be able to flap freely without slop. The propeller parts are oversized for safety. Do not subject them to ultra high power setups. This is not even close to a hotliner, and if the prop doesn't break first with a very hot setup, the plane will.
Prop03 is ~13,3x8" blades. Suitable for 2-3S.
Prop04 is ~11,3x8" blades. Suitable for 3S.
Prop05 is ~9,8x8" blades. This is the one I use with 4S on the prototype.
Prop06 is ~8x6" blades.

The forward EDF housings are printed with a support plug inside hte motor cavity. It should be easy to remove after printing. It's usually best to hammer it out from the front side. The EDF housing parts ade indexed with short pieces of 4 mm rod when glued together. Ton install the EDF unit simply slot it into the top hatch opening and add two screws to the rear using EDFadapter inside the fuselage. EDFadapter01 can be secured to the rear of the fuselage with countersunk M3 screws first. Aftermarket 70 mm impellers can be used instead of the printed one. The EDF housing is made for 28 mm motors with a screw mounting pattern of 19 mm. I suggest 2300-2800kv motor capable of 50A for 4S. I use an old Starmax outrunner. THe plane is capable of taking off from artificial grass without a landing gear, by simply sliding on its belly using the thrust of the EDF.

The nose gear uses a spring for suspension. A hole has to be drilled in the leading edge of LandinggearNose01 to fit your spring. It assembles using M3 screws and grub screws, and a 4mm rod for the steering hinge.It uses the same type of 9g servo as the control surfaces for steering.

Special part description:

Wingroot02-quadcopter.STL - Wing root part to add forward carbon tubes to add a quad copter function for vertical take off and landing.

Aileron01-feathers + other parts ending with "feathers" - Special parts to make feathered wingtips, tail and and control surfaces to make the plane look more bird like.

EDFadapter01 - Solid piece for the EDFhousing screws to grab onto in the rear of the fuselage.
EDFHousing01 - Rear part of the EDF housing, with trailing edge piece that screws onto the rear of the fuselage pod.
EDFHousing02 - Basic front part of the EDF housing.
EDFHousing03 - Basic front part of the EDF housing, with a hole to suck hot air from the inside of the fuselage.
EDFHousing04 - More aggressive looking and curvy front EDF housing.
EDFHousing05 - More aggressive looking and curvy front EDF housing, but missing the motor mounting plate, for hot motors that can soften PLA mounting plates.
EDFHousing06 - Motor mounting plate for EDFHousing05. Can be printed form heat resistant material for hot motors.

Flap01 - Flaps
Flapwingroot01 - Optional center wing section with cutout for flaps. Highly recommended.

LandinggearNose06 and 07 - Optional noses without pan servo mounts.
LandinggearNose08 - Holder for a 32-33 mm long pan servo.
LandinggearNose09 - Holder for a 28-29 mm long pan servo.
LandinggearNose10 - Holder for a 22-24 mm long pan servo.
LandinggearNose10 - Holder for mounting a camera with a 1/4" UNC thread on the bottom.

V-tail01-06 - V-tail parts that replace Hstab and Vstab parts. I recommend using the v-tail as it's lighter and flies just as well.

Wheelmain01 is one half of the wheel hub. Print two for each main wheel.
Wheelmain02 is the tire. Print from flexible filament.
Wheelnose01 is one half of the wheel hub. Print two.
Wheelnose02 is the tire. Print from flexible filament.

Print from PLA. Print parts in the orientation they open.

All wing files, control surfaces and stabilizer parts should be printed at 0,12-0,2 mm layer height with 0% infill, one 0,3-0,4 mm perimeter and three bottom and top layers.

Vstab01.stl do not have internal structure and should be printed with ~5% infill.

Fuselage files should be printed 0,2 mm layer with two perimeters and 20% infill in order to handle the load landings, and weight of a battery in the nose.

If LW-PLA is used for the tail then carbon rods or tubes should be used inside them for added stiffness.