The 4" ultralight, long-range craze is upon us, and I think it's time we figure out which motor, prop and battery combination would give us the longest possible flight time. Just to remind everyone, the goals of this specific build are to be able to:
- cruise for long ranges and actually appreciate the beauty of flying.
- do the above while staying within the stupid 250-gram limitation.
- fly quieter, safer and cheaper, relatively, compared to a typical 7" long-range setup.
Our limitations for these tests are:
1404-size motors only, adding other sizes won't be fair. The good thing is that we have a lot of options for this size:
- AirbladeUAV 1404 (2500Kv, 3850Kv, 4850Kv)
- BetaFPV 1404 3800Kv
- Dave_C FPV/Flywoo Nin v2 1404 (2750Kv, 3750Kv, 3850Kv)
- DYS 1404 (4300Kv, 6000Kv)
- Emax Eco Micro Series 1404 (3700Kv, 6000Kv)
- iFlight Xing X 1404 (3800Kv, 4600Kv, 7000Kv)
- Battery is 2-4S. Anything more (5-6S) would most likely cause us to exceed the 250-gram limit.
- Bi-blade 4" T-mount props only. It seems we only have two options here, and we are going to test with the lower pitch one (low pitch = more efficient, typically), which is the Gemfan 4024-2.
I will be running the tests on my RCBenchmark 1520 thrust stand (hardware info coming soon). For each setup, the goal would be to reach 62.5-grams of thrust (250-grams/4 motors) using the least amount of amperes at whatever throttle point, which I will also take into consideration, since we don't want to pick a winning setup that has its most efficient throttle point way up high (more than 50%).
Of course, these tests are mostly theoretical and ran on a static environment. There are many, many more factors that will affect your flights in the real world, so don't take the results with a grain of salt.
Results coming soon!