The "Cyclone-Rotor" UFO Drone

Description

This is a highly modified tricopter drone design that leverages arm-mounted wings to significantly increase hover efficiency by spinning. A single standard sized servo housed in the center hub rotates all three arms simultaneously and provides extreme yaw control authority.

NOTICE:
I am providing a parts list and 3D print files for this project, because I am nice like that. This is not a project for someone who has never built or flown their own RC model aircraft or drone. I cannot guarantee your success building and/or flying your own since this is such a complex and experimental project. With that said, have fun! You are legally obligated to send me a picture or video if you build one.

Details

FLIGHT CONTROLLER:

A standard flight controller like betaflight or ardupilot will only get you to the standard tricopter with forward flight capability. The controlled spinning flight mode is out of the question without significant modification, and I have no idea how to achieve that with those firmwares, so good luck!

I personally use and recommend my opensource flight controller dRehmFlight VTOL, which runs on a Teensy 4.0 microcontroller and uses easy to understand Arduino code. You will need to configure the control mixer yourself to accommodate the tricopter mixing. Watch the comprehensive tutorial videos to learn how to do this. You will also need to make code modifications to fade out closed-loop control at higher spin rates, and program in the spinning directional control shown in the third video. If this sounds too difficult or you are already confused, this project is probably not for you.

Code and more details: https://github.com/nickrehm/dRehmFlight

PARTS LIST:

Radio: https://amzn.to/3PqNgQv
Motors: https://amzn.to/3RLTBaP
ESC: https://amzn.to/3RJMCPJ
Battery: https://amzn.to/3IU4iUU
Tilt Servo: https://amzn.to/3RFrVnU
BEC 5v Supply: https://amzn.to/3yL3ugg
Teensy 4.0: https://amzn.to/3IR29ZW
Teensy 4.1 (if 4.0 is out of stock): https://amzn.to/3c1OSSw
IMU: https://amzn.to/3Oje9og
Carbon Fiber Arms: https://amzn.to/3IUgi8D
Bearings: https://amzn.to/3OpRDd7
Magnets (for nose cone): https://amzn.to/3zkFlyo
4mm M3 Setscrews: https://amzn.to/3IRXreD
Misc. M3 Fasteners: https://amzn.to/3yToul1

All of the links above are Amazon affiliate links. I receive a small commission for every product purchased at absolutely no cost to you.

3D PRINT INSTRUCTIONS:

.STLs are included in the 'Files' section of this page with required quantities listed in their file names. PLA, PETG, or ABS plastic will work just fine. The nose cone fairing may be printed in LW-PLA to reduce weight.

Solid infill:

collar
gear_arms
gear_servo
motor_mount
servo_mount_spacer
nose_cone

30% infill:

center_hub_cap
center_hub

GENERAL ASSEMBLY INSTRUCTIONS:

Press fit bearings into center hub, 2 per arm mount.
Press fit magnets into top of the center hub.
Slide magnets into the nose cone slots, noting the polarity to match with the center hub. Tack them in place with hot glue to prevent from sliding out.
Slide the servo mount spacer parts over the servo mounting brackets; these provide proper offset of the servo from the center hub to give proper bevel gear alignment inside the hub.
Use M3 hardware to fasten the servo to the center hub and install the servo bevel gear on the servo.
Slide the 10mm carbon tubes through the bearings.
From the inside of the center hub, slide the collar over the carbon tube, then the bevel gear.
Use the M3 setscrews to tighten the bevel gear on the very end of the tube. Slide the tube all the way in to tightly meet the servo bevel gear.
Use the M3 setscrews to tighten the collar so that the arm can not back itself out.
Slide the motor mount on the outside of the carbon tube and tighten using the M3 setscrews. Adjust all three motor mounts so that they align perfectly vertical.
Install motors and route wiring through small access holes into the center hub.
Install electronics; use double-sided foam tape to adhere ESC, flight controller, receiver, etc. to and around the servo protruding from the top of the center hub.
Use velcro cable ties to secure the battery to the center hub cap. Install the center hub cap with M3 hardware to seal the bevel gears within the center hub.
Cut the wings from 5mm dollar tree foamboard. Remove paper from one side and fold over centerline. Hot glue to the carbon tube arms and bevel the trailing edge. The small marks on the wing cutout are to mark where the carbon tubes should align; use these to mark the wings when you glue them to the arms.

This project is released under the CERN open hardware license...

Files

nose_cone_X2.STL

Standard Tesselated Geometry - 772.64 kB - 07/20/2022 at 03:19

Download

center_hub_X1.STL

Standard Tesselated Geometry - 804.77 kB - 07/20/2022 at 03:19

Download

center_hub_cap_X1.STL

Standard Tesselated Geometry - 456.23 kB - 07/20/2022 at 03:19

Download

motor_mount_X3.STL

Standard Tesselated Geometry - 448.81 kB - 07/20/2022 at 03:19

Download

gear_arms_X3.STL

Standard Tesselated Geometry - 256.92 kB - 07/20/2022 at 03:19

Download

Discussions

coarsedamavand wrote 10/16/2024 at 02:29

Excellent project, was wondering if you could please post the CAD files for the parts? That'd be super helpful, thanks and best regards!

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Kartik wrote 10/24/2023 at 14:45

is there any cheaper option for the esc?

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THELUCKg wrote 09/22/2024 at 17:48

watch "The H Lab" on youtube

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gschueller10 wrote 05/19/2023 at 18:19

Hello, I am looking to build one of these and attempt to implement some of my own control code in order to make it have more directional control ( IE being able to have the motors fluctuate speed based on where they are relative to the global frame to make the aircraft pitch while still spinning at a constant speed). I am wondering if the teensy 4.0 flight controller would be able to handle the extra computation that would require.

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Nick Rehm wrote 06/11/2023 at 23:58

yes https://www.youtube.com/watch?v=taU7mRTnrtY

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careycai2007 wrote 02/19/2023 at 05:24

Hi Nick,

I bought the servos you put in the link and changed the scaleCommands() scaling from 180 to 60. However, the servos don't seem to be working (only tiny movements can be observed when I change the PID input). I'm giving them 6 volts and they work fine when connected to a receiver. I also tried printing the pwm signal that's fed to them, and it seems like the teensy is giving them 3030, which is higher than my receiver output can ever be. Could you help me problem shoot?

Thanks!

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Addison Woods wrote 09/02/2022 at 00:51

I wonder if you could eliminate the central servo with a system like this https://hackaday.com/2014/12/16/uav-coaxial-copter-uses-unique-drive-mechanism/

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Aleksandr wrote 08/05/2022 at 18:53

Сама ідея цікава...

Намагалися створити апарат з двома або чотирма гвинтами і окремими сервоприводами?

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Sizhen She wrote 07/28/2022 at 12:56

Looks cool ! I just orderd the parts and will build one soon.

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Apollo Timbers wrote 07/27/2022 at 11:31

This is just good old fashion engineering at it's finest, where you take something one step at a time and test, test, test along the way. Nice finished drone.

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dansam wrote 07/25/2022 at 10:23

excellent project and work, can you share the updated code for the tricopter on github, even if it's a work in progress?. it would help me build one of these too :)

Any plan to control independently the arms with 3 servos?

Are you sure? yes | no

Nick Rehm wrote 07/25/2022 at 12:55

Increase the IMU max gyro measurement to 2000dps in the defines section, increase maxYaw variable to 1800, and go down to the control mixer:

s1 = 0.5 + yaw_pid;

m1 = thro_des + roll_PID - pitch_PID;

m2 = thro_des - roll_PID - pitch_PID;

m3 = thro_des + 0.7*pitch_PID;

Everything else set to 0. That ^^^ is tricopter mixing. It may require to you flip a + to - if something is stabilizing in the wrong direction. Stock PID gains will fly fine using the standard angle controller but may need some further dialing in depending on your power system. You can play around with mapping the GyroZ variable to a 'gain' on those stabilized variables in the control mixer such that they go to zero at high rates of spin--I found this to be helpful since the tricopter stabilization is useless when spinning so fast.

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david.wilks wrote 07/23/2022 at 14:59

Hi, built tricopters over 12 years ago, this looks fun.

One question, what Lidar are you using?

cheers

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Nick Rehm wrote 07/25/2022 at 01:21

tfMini plus, but it is not necessary to fly. It simply helped me collect more consistent data

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The "Cyclone-Rotor" UFO Drone

Description

Details