Swift 16 6S Minimum Mah

[MicroHeli-Nut]

Hi all,

Been bugging Fred bonk awhile on rcg so decided to post here since there's so many swiftiers over here... :mrgreen:

From RR and RCG... I've picked up that 3700mAh are the lowest for 4S... okay... what if I can get 30C packs... can I use a 6S1P 3200mAh (30C) pack for the Swift 16? I'm trying to get the highest possible power at the lowest possible weight and headspeed.

I've at my disposal, these three choices:

A) get the Z20-1500 motor (the 550 motor) with 4S 4350mAh (413g) (25C)

B) get the Z20-1500 motor + 4S 4500mAh (450g) (30C)

C) get the Z30-1100motor + 6S 3300mAh (500g) (25C)

D) get the Z30-1100motor + 6S 3200mAh (550g) (30C)

Looking for USEFUL duration. I know I'm asking for too much... it's like trying to build a Dodge Viper with the fuel economy of a toyota... but I believe :hug: it can be done :mrgreen:

[Tim Tompkins]

After a six min hard flight I restore 3000+ mah's to my flight power 6S 4900 pack. I'm using the Z 30 1100 motor and 550 blades. I wouldn't want to try six mins with a pack rated for less. If you are just cruising around a smaller pack should be fine for six mins but if you want some poping and climbouts get the bigger battery and feel safe. TimT

[Coolice]

Hey,

I was getting 6 1/2 minutes of hard 3D with my 3700mah 6s Swift running 530mm mains and the 600 Outrunner. I have since switched to the 600+ and the same packs and conservatively get 5~6 minutes depending on what I do and put back in the pack just under 3000mah.

Battery size wise I feel for a 550mm main bladed Swift 4000mah is just right for hard 3D, as the bulk of any LiPo weight is on the bottom of the Swift and has be hauled around the head.
I have a new Over-Tec Kokam 30C 6s pack to try which will be ideal I think.

At the end of the day you just need to respect the 80% rule when it comes to LiPo's, only use 80% of it's capacity in a flight.
A bonus is that as soon as you land and remove the load from the battery the voltage rises slightly and so takes the pack further into a safer zone meaning no damage to the cells.

A good pack configuration to make up the 6s pack for the Swift is two 3s packs end to end in one long stick. This again raises the centre of gravity a little and makes the heli feel move lively carrying the weight.
.

[Greybird]

...

[MicroHeli-Nut]

Ok... I get the idea. Thanks for the headsup. Think I will either go with a 4S 4350mAh or 6S 4350mAh. 6.5 minutes of hard 3D sounds nice to me. Hopefully, this will translate to 9 mins for me as I don't do hard or real 3D.

[Coolice]

Hey,

Those packs you mention are a ncie compromise between weight & performance and so will suit the Swift well.

Let us know when you start using them.
.

[MicroHeli-Nut]

Seems I'm down to a 4S 4350mAh (25C)/4500(30C) or 6S 4350mAh (25C)/4500(30C). I'm more or less settled on getting the 1100kV Zmotor.

Any one with any ideas on whether a 5S will be in between or a complete waste of time? Seems not many have 5S setups.

I'm leaning toward a 4S for weight benefits, even thinking of increasing to 5000mAh if possible.

[RAV50]

For hard 3D we require a relatively high head speed in order to get "pop" collective and relatively fast cyclic on ANY helicopter. Consequently we gear our motors relative to their Kv rating and battery Voltage, to give a gear ratio that will result in the head speed we want (2000 to 2200). Head speed consumes a LOT of power.

As a pretty accurate rule of thumb, every 10% increase in head speed will require 30% more power. Or conversely every decrease of 10% head speed will require 30% less power. So to gear down from 2100 to 1890 will require 30% less power. So if we are using 560 blades and using 1200 watts, then we would only need 840. If we drop again to 1710, we would then only require 588 watts. We could be taking our flight time from a "yee-haw" 4 minutes to a more sedate 8 minutes. Just by changing he pinion gear.....while still running the ESC at its' most efficient setting of 100%.

I have also found in the 520 to 560mm blade class, every 10mm in blade length will require about 10% more power to operate at the same head speed.

So considering that, if you are mainly into sport flying with more gentle aerobatics or even less "pop" type of 3D (going for a more smoother type of 3D), then you can consider gearing for a 1600 to 1800 head speed and get more duration from the same power system (motor/battery).

And if you want even longer duration, for more scale type of flying, then gear for 1400 to 1600 head speeds (I have even done loops & rolls and flown inverted at 1500) using short blades (e.g. 515/520mm).

At 1500 you may find yourself easily getting 8 plus minute flights on your 4350's.

:)

[MicroHeli-Nut]

Thanks RAV50. It's exactly the answer I'm looking for. I read that higher headspeed uses higher current, but on the micros it was never that significant on flight time... Your explanation helped to clear up the picture...

Guess I'll be sticking to 4S 4350mAh(25C) or 5000mAhs... with teh Z-30 1100kV motor and try to hit a headspeed of 1700

[MicroHeli-Nut]

Somebody hit me. :lolol I was at the shop to buy a Z30-1100... then after hearing about how hurricanes and erappies are flying at 6S, I decided to get the 800kV motor instead... The main motivation was the need to future proof my Swift for battery technologies to come. There, I can't believe I will be getting an 8S setup at under 3Kg so easily. It's now in my hands...