As I continue to build my Quad’ I have had to solve a few issues. After reading on the ArudPilot website about the compass (and GPS) module, I needed to mount it away from sources of interference; the ESC and motors. As both can output a magnetic field it seems. Again I turned to my trusty 3D printer to produce a design I made to mount the GPS and compass module on a mast. This sits about 100mm above the top of the frame, which is about as far as I can go with the length of its cables.
Masted GPS/Compass module and APM anti-vibration plate
Another point that was made refers to mounting the APM flight controller. Containing an accelerometer and gyro, which are both susceptible to vibration interference, it was suggested isolating them from the frame. GuyMcCaldin wrote a blog that was linked too in the instruction manual where he made a 3D printed isolator (http://goo.gl/2DReB7). I have had to modify the base part to fit around the bolts and provide fixing to the plate. I am currently using some ear plugs instead of the suggested rubber grommets, I’ll see how well they work once I have it all running.
Today the battery turned up and it suddenly occurred to me that the battery would be hanging below the reach of the legs. This meant that the frame needed to be raised up. I have designed and printed some test legs for frame that raise it up by about 75mm. They need more work to be fully stable but I will wait until I have the thing flying.
Landing leg, only 9g!
Well that is about it for now. Mainly just waiting on the motors, props and RC equipment. The latter I shall be ordering soon, just need to decide on how many channels would be best!
Infinite Tadpole 