Pirx Seven – The ultimate custom 7-inch FPV frame, part 1

Do you know this old saying “If you want something done right, do it yourself”? I do and sometimes I just live according to it. Not always, I’m not crazy, but at least from time to time!

I fly 7-inch FPV drones a lot. To be honest, they are my favorite flying devices. There are a few good 7-inch frames, like TBS Source One for example. There is a difference between good and great tho. I do think that Source One is a good frame, there are a lot of things on it that do not make me very happy tho! The list might not be very long, but it is relevant:

  • props in the view
  • limited space to install split-like hybrid cameras
  • no very convinient place to install VTX
  • it’s not that big inside as one might imagine…

Continue reading “Pirx Seven – The ultimate custom 7-inch FPV frame, part 1” »

Your first 7-inch FPV drone

I love 7-inch FPV drones and during the last year, they were my most used FPV gear. For freestyle, cinematic, cruising and long-range. I currently own 3 7-inch FPV drones and 4th one in the assembly process. I think of myself as a 7-inch expert. I’ve wasted enough money and equipment to know what works and what does not work well with 7-inch propellers.

TBS Source One 7-inch FPV drone

If you are thinking about building your own 7-inch FPV drone, here are some tips that might save you a lot of time and a lot of money on wrongly chosen equipment. Continue reading “Your first 7-inch FPV drone” »

Race Day Quads Mach 1 with EMAX RS2 2306 2400KV

This year my friends and I stared a local FPV drone racing series. Nothing serious, just a couple of guys meeting once in a while and measuring times over the track. 100% amateur thing. After the second race, I’ve realized that I do not have a drone designed for racing: more than 400g without a battery! That is just too heavy for any competitive racing. The solution was simple: I need a good racing machine. Frame designed with racing in mind. Much lighter, simpler, and more agile than the current one. Preferably Stretch X design.

As a result, Race Day Quads Mach 1 was born

Race Day Quads Mach 1 is a straightforward frame. Four arms, bottom plate, top plate, four standoffs, and 3D printed camera mount. It turns out it’s all you need for racing. Everything above that is just a dead weight that serves no purpose during the race.

Comparing to my previous racer, Mach 1 was lighter by almost 150g. Almost a third lighter! And I could feel the extra swiftness and agileness while flying. Race Day Quads Mach 1 helped me to get the second place at the end of that racing season.

7 inch quadcopters fly like shit? Well, kind of, yes…

So, you got yourself a 7-inch quadcopter drone, you try to tune it, and you finally discovered that something is bloody wrong? Whatever you do, no matter how long you tune the PID gains and filtering, you can not get rid of jello and some strange vibrations? Welcome to the club mate!

Apparently, scaling 5-inch frames to 7-inch ones in XY axes does not work! Longer arms equal lower modal frequencies. Bigger propellers equal lower vibration frequency. After combining both factors, we have frame oscillations that are happening on the hardware level. No way you can tune that thing out. To make thing worse, 2205 and 2206 (even 2207) motors does not have enough torque to quickly change 7-inch propeller rotation speed.

For the details, watch the video.

INAV Airmode and Motor Stop on Multirotors and Fixed Wings

What are Motor Stop and Airmode features in INAV and how they differ from each other when used on multirotors and fixed-wing airplnes? Should you use Motor Stop on multirotor? Should you use Airmode on a fixed wing? Long story short:

  • On multirotors, Motor Stop not recommended to use while Airmode is recommended to use. More than that, you can not use them both at the same time, since they exclude each other!
  • On fixed wing aircrafts Motor Stop and Airmode are highly advised to use together.