Minis and FPV

Apr 2 2015

I’ve got some time into the hobby to actually share some experiences that could perhaps help someone who is just starting.

Cheap parts

I like cheap parts just like the next guy, but in the case of electronics, avoid it. Frame is one thing. Get the ZMR250. Yes it won’t be near as tough as the original Blackout, but it will do the job just fine for a few crashes. Rebuilding aside, you can get about 4 for the price of the original. Then the plates give. But electronics is a whole new category. If you buy cheap ESCs they will work fine. Until they smoke mid flight. They will claim to deal with 4S voltage fine. Until you actually attach a 4S and blue smoke makes its appearance. Or you get a random motor/ESC sync issue. And for FPV, when a component dies mid flight, it’s the end of the story if it’s the drive (motor/esc) or the VTX or a board cam.

No need to go straight to T-motor, which usually means paying twice as much of a comparable competitor. But avoid the really cheap sub $10 motors like RCX, RCTimer (although they make some decent bigger motors), generic chinese ebay stuff. In case of motors, paying $20 for a motor means it’s going to be balanced and the pain of vibration aleviated. Vibrations for minis don’t just ruin the footage due to rolling shutter. They actually mess up the IMU in the FC considerably. I like Sunnysky x2204s 2300kv for a 3S setup and the Cobra 2204 1960kv for a 4S. Also rather cheap DYS 1806 seem really well balanced.

Embrace the rate

Rate mode is giving up the auto-leveling of the flight controller and doing it yourself. I can’t imagine flying line of sight (LOS) on rate, but for first person view (FPV) there is no other way. NAZE32 has a cool mode called HORI that allows you to do flips and rolls really easily as it will rebalance it for you, but flying HORI will never get you the floaty smoothness that makes you feel like a bird. The footage will always have this jerky quality to it. On rate a tiny little 220 quad will feel like a 2 meter glider, but will fit inbetween those trees. I was flying hori when doing park proximity, but it was a time wasted. Go rate straight from the ground, you will have way more fun.

Receiver woes

For the flying camera kites, it’s usually fine to keep stuff dangling. Not for minis. Anything that could, will get chopped off by the mighty blades. These things are spinning so fast than antennas have no chance and if your VTX gets loose, it will get seriously messed up as well. You would not believe what a piece of plastic can do when it’s spinning 26 thousand times a minute. On the other hand you can’t bury your receiver antenna on the frame. Carbon fibre is super strong, but also super RF insulating. So you have to bring it outside as much as possible. Those two don’t quite go together, but the best practice I found was taping one of the antennas to the bottom of the craft and have the other stick out sideways on top. The cheapest and best way I found was using a zip tie to hold the angle and heatshrink the antenna onto it. Looks decent and holds way better than a straw os somesuch.

Next time we’ll dive into PID tuning, the most annoying part of the hobby (apart from looking for a crashed bird ;).