Justa mini fpv

General

Over the past year or so, the 250-class 'mini racer' formfactor has become the de-facto standard for fun-oriented FPV (First Person View) flying. There are many frame-designs out there in this class. The ZMR250 is one of them and, likely, one of the cheapest.

ZMR-250

This frame is a clone/ripoff/whatever of some of the other designs that were already out there. The design-plans seem to be in the hands of quite a few chinese carbon-cutting shops. There are models available that are not even carbon, too. Glass-fiber and glass-fiber/carbon laminate versions are also available.

The full carbon-frame version can be found for around €30,- online. BangGood.com is a good place to go looking for it.

The design does have some issues, however; mainly in the area of the motor-arms. People have observed that while they may not actually be too thin, they do seem to have too little material reserved around the holes to resist some of the forces that come onto the aircraft in a crash.

Furthermore; unlike some other designs, the ZMR250 comes with 100% metal screws. It is advisable to replace those involved in the top/bottom-plate assembly with Nylon bolts, instead. These should shear off cleanly in the case of a crash, leaving your carbon plates intact for as much as possible.

The parts

The design is a run-of-the-mill quadcopter setup with no special gimmicks except that it has an FPV set strapped to it, of course. Next to that, telemetry is a 'big thing' in the sense that it allows careful monitoring of battery-performance over a large distance (which makes an audio-alarm with a beeper rather less useful).

Given the small size of the frame, the rotors are based on the 5030 (5 Inch diameter, 3 inch pitch) propellor size.