DemonRc Legit 4x lite 6s

By BloodyLordV on Dec 05, 2018

14  638  5

So, I've started experimenting with ultralight 4 inch builds about 2 years ago. Each time those were extremally nice machines with two, major, flaws Short flight time and a huge LiPo sag. Fortunatelly those problems trouble me no more! Say hello to my newst ultralight 4inch low kv 6s racer!

Firstly, as it's the most important factor for the 4 inch build - weight. I think that in this case it is execptionally good - 150g without lipo and 254g with 6s 550mah lipo.

What made this build possible are the motors. And what can I say? Those are the highest quality motors I have ever seen. Hobbywing Xrotor Race Pro 1408 2400kv. Compared to the Brotherhobby 1507 those have a much stronger magnets (N54) which are packed much closer together. Also the gap between stator laminations and magnets is much smaller than in the case of Brotherhobby 1507. The motor is extremally notchy.

Amp draw is quite low, the maximum number I was able to achive during flight is 52A for the whole drivetrain. That is why I am able to use xt30 connector without melting it. The lipos also does not sag and I got avarge of 3:30 minutes of flight time on the race track (compared to about 2 minutes of flight time in case of 4s 550mah and BH1507 3600kv).

The frame is a prototype frame given to me by my sponsor DemonRC, which I am very thankful about and is called DemonRC legit 4x lite.

The rest of the parameters:
TWR circa 15,27:1
Disc Load 5.07.

Photos

Discussion

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fovea   Jan 03, 2019  

thank you very much - i enjoy it for sure. nice track, nice flight - looks awsome "stif in nimble snappy turns" - pleasure to see. i will check your yt frequently - hoping for more.
(at the moment i rebuild my old brushed micros :-D, the opposide saggy and underpowered, not stif, no response, not nimble - but pure simply.
i plan to build a clone of yours and sometimes i would try a more heavy 4inch 6s version to compare. probably with 2204 6s - i dreaming about 1806 6s motors and searching a superb 4inch prop, like the hq4043 v1s but more pitch. some like the dal t5051c, an ultralight triblade but as 4inch.)
thanks a lot for your influence

fovea   Dec 06, 2018  

please send me this build! sounds perfect. thank you for opnenig my horizon for 4inch 6s. I prefer the agility and response of lightwight 4inch. sadly there is not much choice for 4", lipo sag and loosing the torque is a problem, it determinate the nimbelness: it sounds like 6s fix this issue ? can you post a video?

BloodyLordV   Dec 26, 2018 
1

Sorry for beeing late, unfortunatelly I damaged my phone trying to record the DVR. But here it is. I hope you'll enjoy it.

https://www.youtube.com/watch?v=kjWN2RHWxX0&feature=youtu.be

fovea   Dec 06, 2018  

please send me this build! sounds perfect. thank you for opnenig my horizon for 4inch 6s. I prefer the agility and response of lightwight 4inch. sadly there is not much choice for 4", lipo sag and loosing the torque is a problem, it determinate the nimbelness: it sounds like 6s fix this issue ? can you post a video?

BloodyLordV   Dec 06, 2018 
1

I have problems with my DVR, but the next time I will go flying I'll try to record something :D

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