Small, efficient quad

[HDtallrider]

Hi all! I accidentally ordered 2, 2s 5000mah batteries instead of 3s. It would cost a bunch to return them. I thought I might build a 7.4v quad and try for some really long flight times just for fun. I have been searching for a couple days and am not having much success finding motors strong enough and efficient enough to lift a quad that would probably be around 500+ grams AUW. I am completely open to any advice including frames and props as well as motors. Thanks!

 

[GJH105775]

Ok, you can buy motors designed for 2S (I am sure you already knew this) When choosing a motor for this you want to get one that has a little higher KV and the number before KV should be higher. This number is the torque, you could make a bigger quad that is fairly efficient with 2S, or just wire them in series and have a 4S 5000MaH set.

 

[HDtallrider]

I have been doing some more research and the pickin's are slim! The batteries are 285 grams by themselves. The best I can come up with for a frame with everything, less batteries, is about 240 grams. I found that a RC Timer 1806 2300kv with a 7x2.0 cf prop can just about due 550 grams at 50%. The KDE 1806 2350 kv with a 8x2.4 cf prop can easily due 750 grams with a little better efficiency. The problem is the KDE is over 3 times the price! I wanted to include FPV but thats too heavy. I'll keep looking....

 

[GJH105775]

deciding on the parts is paying for them xD.

 

[HDtallrider]

I hear ya brother! I'm gonna keep messing with the frame assembly and see where I can trim some weight. I can live with a little less strength. I want slow and easy just to see how long a flight time I can get. I don't intentionally do acrobatics. My landings just look like it...........

 

[GJH105775]

Haha, I finally got landings down. To land I was slowly dropping the throttle to 0. I found that if you let it drop enough for your quad to descend and just leave it there until you touch down it is a lot better. I still have not got landings down when I have any forward momentum (I can do all kinds of rolls, flips, and cart wheels) xD.

 

[HDtallrider]

Yeah. I do those too. Just not on purpose........... I will eventually get it. In the meantime I am having a blast building, tearing down and building again. Each time I read threads in the forums I learn something new. I just wish what I learn would be less expensive. I am going to use this little quad to experiment and hopefully save some cash. I really want to build a quad capable of FPV and near 1 hour flight times on a 10k Mah battery or less. I'm going to use this one as a scaled down version. Should be fun. When I get it fine tuned I'll scale it up. P.S. I may have some new info on the cryo stuff. I'll post it when I get it.

 

[GJH105775]

Ok, sounds great. It is a lot easier to get bigger flight times on bigger props. a 10Ah battery would give a good flight time if you could work out the best prop and motor combination. You might want to play around on this calculator a little to see the longest theoretical flight time.

 

[HDtallrider]

That's what I was thinking for the big quad. For the little guy I already have the batteries. I'm gonna go for 7 or 8" props depending on if I hit the lottery and can afford the KDE motors. This is kind of a proof of concept . Hopefully on the cheap.

 

[GJH105775]

Haha, most of these with good flight times are a little expensive.