Table of Contents
TBS Caipirinha VTOL
TBS Caipirinha is a flying wing rc airframe popular for FPV flying. It is very easy to assemble and robust against hard crashes. In case anything breaks one can always fix it with some hot glue. This makes the TBS Caipirinha a perfect platform for flight testing. The TBS Caiprinha can be modified very easily to become a proper Fixed Wing Vertical Takeoff and Landing (Fixed Wing VTOL) airframe. The following will explain what exactly you need to do to get the TBS Caipirinha into the sky.
- 2x Brushless outrunner motors 1800 KV, max. 45g: You can use any brushless engine of your choice but it is recommended to follow the recommendations provided. First flight tests have been conducted with these.
- 2x ESC Brushless Motor Speed Controller 30A: RC Timer 30A ESC
- Multiple 2200 mAh LiPo batteries, suitable for at least 25A/30A discharge.
- 1x Propeller R8x4.5: rotating clockwise, diameter:8 inch, pitch: 4.5 inch
- 1x Propeller L8x4.5: rotating counter clockwise, diameter:8 inch, pitch: 4.5 inch
These PX4 autopilot parts are required:
- 1x Pixhawk autopilot): 3D Robotics Store (includes power module)
- 1x u-blox LEA GPS module: http://store.3drobotics.com/products/3dr-gps-ublox-with-compass (you don't need an additional one if you already have one included in the Pixhawk autopilot kit above) check for updated versions on ordering
- 1x RC Receiver: List of compatible RC receivers
- 1x Radio modem: List of compatible radio modems
- 1x min. 2GB microSD / microSDHC / microSDXC card: List of compatible memory cards
You will either need to construct mounts for the engines yourself or wait for these to become available at the Team Blacksheep Online Store. Check out the following assembly section to find an example of a self-made, rapid prototyping motor mount.
General Airframe Assembly
The original assembly manual for the TBS Caipirinha can be found here.
This manual contains alot of information which you don't need if you just want to get flying. Very nice assembly videos can be found here and here.
Note: These tutorial will show you how to assemble the airframe, install the servos and the mount the elevons. If you want to use the Caipirinha as a VTOL then you can skip the rest of the video and proceed with the assembly instructions for the VTOL below.
Autopilot & other Electronic Components
Note: You can use Velcro Tape to mount most of the components to the airframe. This is very convenient for rapid prototyping because you can always change the locations of the individual components easily.
- Mount the Pixhawk autopilot just behind the battery compartment as shown in the picture below.
- Mount the power module between the nose of the plane and the battery compartment.
- Mount the GPS module as shown (on the right side of the battery compartment in the picture below).
- Mount the radio receiver anywhere you like (maybe not on a propeller :) )
- Plug motors into main_out(1-2) servo rail
- Plug servo into main_out(3-4) servo rail
Motors with Mounts
- you can use flat plastic/metal pieces to attach motors to the wing
- you can put tape on the wing and hot glue the pieces on top → like this you can always remount them somewhere else and in case of a crash the mount will just rip off
- you will also need a way to attach the engine to the flat piece → be creative or wait for Team Blacksheep to provide fancy motor mounts :)
- mount the airspeed sensor in a location which is not affected by the airflow induced by the propellers
Picture will be updated soon!
At the moment the software with VTOL support is available from the master branch of the PX4 Autopilot Project.
- set the autostart ID using QGroundControl to 13001
- in QGroundControl assign a channel of your remote radio control to “aux1”. This channel can then be used to switch between multicopter and fixed wing mode.
- in QGroundControl you have to set the correct rotation of your autopilot depending on how you have oriented it. The neutral pose of the vehicle is when the nose is pointing up (multicopter mode)
Note: The current code base paves the road for VTOL applications but it is still in its early phase. At this moment you will probably need a good understanding of the PX4 code base and some flying skills to operate the caipirinha VTOL successfully. We are putting a lot of effort into developing the VTOL code base further.