The last few days (with almost continuous rain outside), I was looking into open source software for airplane design again. It has been a while since I designed my last flying wing with XFoil and AVL, and WOW how things moved forward! With XFLR5 there is now a comfortable environment which integrates most of the functionality XFoil and AVL offer. It also includes really nice post-processing and visualisation.
As I want to try the CNC router at the FIX Maker Space for cutting foam cores of wings, I needed a way to interface XFLR5 with CAD/CAM. Sadly it does not support direct export to any common file format. But I sat down yesterday night and wrote a translator from XFLR5 wing format to ASCII STL files: XFLR5-STL@github
Now I can import the generated STL file in MeshLab, FreeCAD, PyCAM, or OpenSCAM for the next steps towards CNC routed foam cores
After I recently upgraded my Desktop-PC with a new mainboard/CPU/memory/graphics combo, I had my old mainboard with a Core 2 Quad Q6600 processor and 4GB of RAM lying around.
Adding a new power supply and a spare hard drive, I installed Proxmox, an open source virtualisation platform. It allows you to create and manage virtual machines via a convenient web interface. After setting everything up with the practical USB-stick installer, I removed the unneeded graphics card to conserve energy. With the default frequency governor ‘ondemand’, the CPU usually throttles down to 1.6GHz and the systems just draws about 50W without load. Using lm-sensors and fancontrol, I configured the CPU-fan to just run when needed, so the system is usually rather quiet.
With the Ubuntu Server 14.04.2 template I created, setting up a new VM for some tests is really a breeze! Right now, I’m giving InfluxDB with Grafana a try for sensor data logging and visualisation.
For the still ongoing Graupner mc-17 remote control update project, I need more I/O channels from the Teensy 3.1. By default it breaks out 28 breadboard friendly pins, but on the bottom are another 14+ solder pads with more analogue and digital I/O. By mounting the Teensy 3.1 upside-down, these solder pads become quite accessible: