FPV Part II – Modding the Quad

The FPV conversion continues. After finishing the ground station, I’ve been adding camera and transmitter gear to the tricopter and quadcopter. The tricopter is, in theory, ready, but I’ve not had a chance to test it as the weather continues to be rubbish, so I’ve been playing with micro FPV gear for the quadcopter instead.

I originally tried converting a micro security camera into an FPV camera, but rather embarrassingly let the blue smoke out as I was attacking it with a soldering iron, so opted for a simpler dedicated FPV camera and transmitter instead. I soldered them directly to the LiPo plug in the first instance, but although I got a decent picture when the quadcopter was off, I got a lot of interference from the motors as soon as I armed it (I’m using a single LiPo to power both). I solved that with the use of a Pololu 5V switching regulator, and now get crystal clear video even at full throttle. The whole FPV setup, including regulator, weighs 4g. I’ve also added a Walkera-style plug so that I can run the quad off of Hubsan X4 compatible batteries, which are not only cheap and readily available, but much more responsive that the stock cells; the higher C rating really improves the throttle response.

To make room for the video gubbins on the top of the quad, I moved the DSM2 receiver to the bottom. I desoldered the cable plugs and instead soldered the Rx directly to the board, saving a little over a gram in weight. I also added landing gear in the form of zip ties. They’re light (0.1g per leg) and flexible, and since I’ve wrapped the motor wire out of the way around the arms, they provide good protection for all the components.

All in all, it flies really well. I’ve only added about 3g in weight from stock and only lost about 20s from my flight times as a result, but ended up with a much more responsive craft WITH FPV! It’s serious fun to fly, even if it is a bit tricky as the camera has a narrow FoV. I might swap the lens for a wider angled one in the future, depending on how much better I (don’t) get with practice.