3s or 4s?

[Quad350qx3]

I just bought a used 450 pro DFC with castle Phoenix ice 50 and a scorpion hkii 2221-10 3000 kv motor. It has the 3gx and a spektrum satellite reciever. Just wondering how many cells I should run on this? I need some quick advice before the hobby shop closes lol.

[alyon187]

Depends on what your pinion is and what you want. 3s I believe will be the better choice for the time being. I have that model and I use zippy 2200mah, pulse 2250mah, and eflite 2200mah

[gimbleguy]

Originally Posted by Quad350qx3

I just bought a used 450 pro DFC with castle Phoenix ice 50 and a scorpion hkii 2221-10 3000 kv motor. It has the 3gx and a spektrum satellite reciever. Just wondering how many cells I should run on this? I need some quick advice before the hobby shop closes lol.

4S, just make sure you get the right pinion for your desired headspeed and flying style.

[Quad350qx3]

I tried 3s just cause I have plenty from my 450x... I'm gonna run 4s because it felt sluggish compare to my 360 CFX.

[dogbreath]

Since you have those batteries, it would be cheaper to change the pinion first and see how it performs. Dan

[Quad350qx3]

It will run better, more efficient and cooler with the 4s vs using bigger pinion. What do you guys think?

[gimbleguy]

correct

[Bladefx]

I would do 4S if you can get a 11:1 gear ratio

[RC/DC_5000]

4s is the dream on 325mm blades. It's so good. Your motor is also 600 Kv less than what I was using on my 4s DFC. So you should have an a pretty easy time finding the right gearing. My extra 600 Kv was spinning it fast and I had to switch over to straight teeth to get the small pinion I needed for a reasonable HS. I think it was 11:150. This was a couple years ago.

GOGO RC and Ebay are good places to find those extra small helical pinions or straight tooth pinions.

[boredom.is.me]

If you need parts, I get mine from Tarot-RC.

I'm running 11 pinion with a 121 spur (11:1) with a 3400kv motor. One of my two batteries bit the dust when my tail gave out in flight, so I need more. I technically have a 480 (Tarot stretch) swinging 360mm blades. I personally don't have the skills to need any extra power. 3s is also a lot cheaper than 4s. With that said, should I stick with 3s, or jump to 4s?

Sorry for the jack.

[satgod]

Did the 4s thing and if your going to change it up go on and make the move to 6s and dont look back

I liked the 4s setup but a 1750 or 1800kv 6s system is where its at

[Bladefx]

I'm running 11 pinion with a 121 spur (11:1) with a 3400kv motor. One of my two batteries bit the dust when my tail gave out in flight, so I need more. I technically have a 480 (Tarot stretch) swinging 360mm blades. I personally don't have the skills to need any extra power. 3s is also a lot cheaper than 4s. With that said, should I stick with 3s, or jump to 4s?

with the 4s and governed to 2700 rpm HS I am getting 7 min flights. ymmv

[gimbleguy]

Originally Posted by boredom.is.me

If you need parts, I get mine from Tarot-RC.

I'm running 11 pinion with a 121 spur (11:1) with a 3400kv motor. One of my two batteries bit the dust when my tail gave out in flight, so I need more. I technically have a 480 (Tarot stretch) swinging 360mm blades. I personally don't have the skills to need any extra power. 3s is also a lot cheaper than 4s. With that said, should I stick with 3s, or jump to 4s?

Sorry for the jack.

If you have a stretched 450 swinging larger and heavier blades(main and tail), longer boom, you're better of going the 6S route. Yes with the 6S setup you're motor will be heavier and probably your lipos too. The whole 450 Stretch is a heavy setup, so this is where the powerful 6S motor and 6S lipo will shine.

3S and 4S setups are ideal for stock 450s. IMO

[boredom.is.me]

Thanks Guys

[EjectEjectEject]

For what it's worth, I've run 3S, 4S, and 6S extensively on my 450 class birds.

Here are some thoughts ...

3S was good for learning.

4S was like bolting on a turbocharger (with blade speeds up to 3300RPM)

6S was in essence no real difference to 3S; yep - it's twice the voltage, but that setup is used with a motor that NEEDS twice the voltage to turn at the same equivalent speed. Yep - it's only 1/2 the current, but a battery that's the same size as a 3S battery can only deliver 1/2 the current for the same capacity. Yep - a 6S setup IS more efficient than a 3S setup as you lose less through the ESC as heat - but - if you compare what's lost through the ESC it's actually very minor compared to what's delivered to the motor - so it becomes an efficiency gain that's "good in theory" but "pretty much un-noticeable" in practice. The 6S killer for me was the batteries; because there are twice as many cells as a 3S battery I had to fly more conservatively time-wise so that I didn't under-volt any of the 6 cells due to cell imbalances (in essence 6S batteries give twice the opportunity for a weak cell) (never had that issue with 3S batteries).

Ultimately it came down to an energy management exercise; 3S and 6S were both lifting the same amount of energy whereas the 4S setup was lifting 33% more energy (each cell is 2450mAH, but 4S has 4 of them).

The 4S setup has insane performance (3500KV KDE Motor, 10T pinion); 140KM/hr+ top speed (straight and level) 2700f/m straight up. It is a little nose-heavy, but the FBL controller compensates seamlessly for that. It does make the bird a bit heavier - so a little harder doing things like tic-tocs etc.

Hope this helps someone.