Introduction: Drone With Dynamic Tilt Arms
I started this project from at summer 2015. Idea was create drone with moving arm feature. Frame is build from carbonfiber plates, aluminium standoffs, and 3D prints. Arm are 16mm carbon tubes. I didnt want to use any special, expensive or rare materials or components, so every component can be found from internet.
Main components used in this build.
Carbon/3D print -frame
RCX 2208 2050kv
6045 BN props
Frsky D4R2, using PPM
Naze32 rev5 with custom cleanflight firmware. (Tilt arm support should be available in standard cleanflight soon)
Littlebee 30A esc's
EMAX ES09MA servo
Some cheap camera (... that will be will be replaced with Runcam swift soon)
PDB with OSD, MW-OSD 1.6 firmware.
US-100 sonar (5V)
RGB LED strips (WS2811)
Step 1: 1. Design
I wanted to build fast and small frame. I used cad system for design all parts. I choosed to use simple link system for moving arms.
Some of the measurements of components was found from internet, but I did measure and fix all components before finished design.
I designed wireframe skeleton with some parameters, so I could easily modify dimensions and mechanics during design.
After that, designing was pretty straight forward. I created components, attached them to skeleton design one by one.
Step 2: Frame Build: 3D-prints
When all mechanics was ready, key components arrived and measured it was time to get 3D prints and carbon plates.
3D prints: I didnt have 3D printer back then, so I just ordered components from Shapeways.com. They have nice GUI that allows you upload your own designs using .stl format. You just upload your files, choose material you wanna use and add them to you shopping cart like any webstore. I choosed strong and flexible material. Week later UPS delivere huge box with very small plastic components inside. I used very bright orange nitro sellulose paint and clear varnish to make my drone more visible.
Later I had to make some re-desing for new external components. Like many project before, you always find some new features you like to add later. I added GPS and sonar later. I made mounts for those using own ABS prints. I used asetone to finish surfaces of those prints.
Step 3: Frame Build: Carbon Plates
All carbon parts was planned to fit A4 paper. My original idea, was print all parts to paper and clue that on carbon plate. Then I could use dremel tool to cut carbons accurately by just following outlines. Carbons I used was 1.5-2.0 mm thick. I was bit lucky with those carbons. My friend had CNC cutter for carbon plates, so he did all cutting for me.
Diamond dremel tools are great for carbons. I did use it for some tweeking those plates.
I recommend, that you do dremeling outside and use somekind of breathing protection. Carbon dust is bit nasty. Wash all components and tools afterwards.
Step 4: Frame Build: Assembly
I used M3x6 and M3x8 hex socked head screws for assemling. I fitted all screws before tightening to make sure everything is lined up.
I fitted motor mounts to arm tubes and used sharp spike to make markings for holes need for cables. Then I used dremel tool to cut openings. Quick clue can be used to finish edges of all cuts.
Step 5: Adding Electronics
PDB I used have build in 12V and 5V regulators and outputs for both. I use 5V for flight controller (Nace32 rev5), servo, sonar, gps and LED strips**. 12V is for video transmitter and camera. Using modern PDB's are very easy: everything is marked on board and sellers have wiring diagrams too. YouTube is excellent tool for getting info how to setup all components and firmwares. Because this was my first drone build ever, I had to get few usb adapters to setup everything.
Setting up tilt drone, is not very much different compared any diy racer, but there are some specialities. Because dynamic tilts are not very common yet, its not supported in normal cleanflight, you need to use 10.1 beta or tiltflight You can find those from chrome store.
Only FC that is supported in those is Naze32 rev5. After flashing firmware, you can choose tilt quad from confiquration menu. There is tab for tilt arms too.
You need to assign one channel for tilt arm control. I used one of potentiometer in taranis radio for that. Middle position is normal setting where arms dont move. Turning pot clockwise, arms rotate forward manually. When turning pot counter clockwise, dynamic tilt mode is active. Arms follow pitch stick movement. http://youtu.be/BsWNes7PXq4
Warning: When you test/setup your drone, make sure you do testing WITHOUT PROPELLERS. I sliced curtains and ruined wall behind them. I was lucky that my drone didnt jump on me. My wife wasn't very happy...
** LED strips should work 5V voltage, but I had lots of blinking when when setting them with Naze. I tested with adjustable power source and strated to drop voltage. At 4.2-4.3V I got stable lights. I added diode to led +5V lead and 480ohm resistor to signal wire and blinking was gone using 5V output on PDB.
Step 6: Extras
I wanted to add some extra features like sonar and GPS. I designed 3D printed mount for that. I followed Painless360 instructions for setup in Youtube.
I also added sonar. I designed integrated landing skid with build-in sonar mount. I used ABS prints and 5mm carbon tubes for that. I used same idea to create housing for receiver and video transmitter.