Swift 16 550 Flight Videos

[FR4-Pilot]

Newly built Swift 16 takes to the air This one can run lower head speeds due to the 800kV motor, the assortment of pinions I have, and the active freewheeling capability of the YEP ESC.

I have the red/yellow fiberglass canopy to trim and put on, but need to find some grommets that fit first ....

[ame]http://www.youtube.com/watch?v=NhC70V2uLcY[/ame]

Build highlights: http://fr4pilot-swift16arf.blogspot.com/

[Digger1973]

It's looking smooth john. I have been eyeing a gopro pen cam to mount on mine.

Sent from my HTC One V using Tapatalk 2

[FR4-Pilot]

GoPro pencam (?). Now you've got me curious ....

[Digger1973]

Yeah. I been eyeing one. My boss is getting one for the coating station on one of the machines at work so I am waiting to see how well it works in a rough environment.

Sent from my HTC One V using Tapatalk 2

[FR4-Pilot]

I didn't see it on the GoPro website - is it new?

[Digger1973]

I call it a pen cam but it looked like an over sized pen. Once they get one at work I will try to get a picture of it.

Sent from my HTC One V using Tapatalk 2

[FR4-Pilot]

[ame]http://www.youtube.com/watch?v=avk3IIIVpnE[/ame]

Here's a 4 minute test flight with two 3S 2200 35C packs wired in series. 75% flat throttle curve. Standard 0-50-100 pitch curve. RPMs started out around 1510 and ended at around 1370 - extra blade pitch (& drag) required to compensate. Flew okay, but I think I can improve things with different throttle & pitch curves. Batteries, ESC and motor all came down barely warm. Managed to get 4 mins out of this setup. All cells around 3.83V after flight. (Need to see how many mAhs were used). Next will try blades with less drag (Edge 523 CFs), less steep pitch curve, a slightly sloped (up) throttle curve and see if overall flight response & flight time improve. No governor.

[ngin]

A pack made of of 2 x 3S/2200/35C packs is really a 6S/2200/35C pack. This is quite marginal a power supply to properly operate a Swift 16 at 1500 rotor speed, unless you want very short flights and a big chnage in rotor speed as the flight progresses, just as you have experienced.

That is simply because to turn blades of 520mm to 550mm in length at 1500 rotor speed will require approximately 420 to 440 watts. That amount of power is far to much for a battery pack of only 2200 mah.

[FR4-Pilot]

Yes, I'm only expecting a 5 minute (approx.) flight with these batteries, low RPMs and scale-like flying/hovering.

22.2V x 2.2Ah = 48.84Ah, which is the same capacity pack Century includes with it's RTF Swift - 4S 3300 (4 x 3.7V x 3.3A = 48.84Ah). Century claims 12-15 minute flights with a 48.84Ah 20/30C pack - the math says not, more like 5 minutes. Anyway, it got me thinking - time for a little experiment ...

I want to see if I can use two of my smaller batteries, one mounted below, and one inside the canopy on the tray, to avoid having to cut up the factory painted fiberglass canopy, which would be required if using a typical 6S pack. According to many happy Swift pilots, the heli flies great at 1500 RPM, and I used the figures from Leisure Tech's website that indicated 400W required for an average Swift at 1500 RPM.

Two 3S (11.1V) 2200 35C packs in series = one 6S (22.2V) 2200 35C pack

2200mAh x 80% = 1760mAh (1.76Ah Max capacity of pack to use - leave 20%)

400W / 22.2V = 18A (Average current during the flight)

Packs are 35C, so 2200mAh x 35C = 77,000mA or 77A (Max current from batteries - 18A should be fine).

1.760Ah / 18A = .0977h x 60min/h = 5.8666 minute flight.

So if above info is correct, I should be in the ball park for a 5 minute flight.

If 440W is the actual power required, then the calculated flight time drops to 5.325 minutes. Still in the ballpark for a 5 minute flight.

Again, just an experiment. It may just be that the fiberglass canopy will have to be cut since it cannot contain a 6S pack, I'd rather not though if there's an option. I hope I'm not missing something in my calculations (?) Some overhead rules-of-thumb perhaps ...

I would be interested to know how 12-15 minute flights are possible with a 48.84Ah pack on the RTF Swift, especially since it's geared for around 2000 RPM which puts it's power requirements around 800W ...

[MotorRotor]

Originally Posted by FR4-Pilot

Yes, I'm only expecting a 5 minute (approx.) flight with these batteries, low RPMs and scale-like flying/hovering.

22.2V x 2.2Ah = 48.84Ah, which is the same capacity pack Century includes with it's RTF Swift - 4S 3300 (4 x 3.7V x 3.3A = 48.84Ah). Century claims 12-15 minute flights with a 48.84Ah 20/30C pack - the math says not, more like 5 minutes. Anyway, it got me thinking ...
........

I would be interested to know how 12-15 minute flights are possible with a 48.84Ah pack on the RTF Swift, especially since it's geared for around 2000 RPM which puts it's power requirements around 800W ...

First your figuring is on the right track and it will take about 400 watts to hover a light Swift 16 if all is geared to give you a 1500 head speed when used at the most efficient settings in the power system, which would be at a 100% throttle setting outside of the governor mode. As soon as you start decreasing that setting in order to attain a specific rotor speed, then you are inducing inefficiencies. So depending on the ESC you are using you may be introducing a 5% to 15% inefficiency into the system.

Over the years, I have found the C ratings on may brands of batteries to be suspect for this type of calculations. They can serve as a guide line at best. So considering the above, I can see how a 5.8 expected flight time can drop to a 4.8 flight time in the real world.

As for the 12 to 15 minute flight claim by Century on their RTF - I certainly agree that it is impossible with the battery pack supplied etc. They may mean that the heli can get those flight times, if one gears for a lower head speed, and uses a much bigger battery pack as someone on RCGroups did a few years ago. If memory serves, I believe he was using 2 x 4S/5000 packs in parallel and getting 12 to 15 minutes.

[Dennis P]

There is only one way to find out FR4 and that is to try it.It will be interesting to see how the YEP governor with active free wheel effects the flight time.I really like how efficient the active free wheel is in the Kontronics ESC's. Keep us up to date on your experimenting.

[FR4-Pilot]

Flight #2 Followup

I just recharged the packs in series (as a 6S pack) and put 1180mAh back in.

This is great news!

Flight #2 was approximately 4 minutes & 5 seconds = .06805555 h

1.18Ah / .0680555h = 17.339A (Average current draw from batteries).

17.339A * 22.2V = 384.926 Watts (Required to fly the heli)

This results in a projected flight time of

1.760 Ah / 17.339A = 6.09 minute flight = 6 minutes 5 seconds (leaving 20% in pack)

I would say that 5 minute flight is looking very doable. Especially with some CF blades (less drag), warmer weather, and forward circuits with translational lift.

[MotorRotor]

Originally Posted by Dennis P

There is only one way to find out FR4 and that is to try it.It will be interesting to see how the YEP governor with active free wheel effects the flight time.I really like how efficient the active free wheel is in the Kontronics ESC's. Keep us up to date on your experimenting.

+1 - How did I miss the fact that he was using an ESC with an active free wheel? This will certainly effect the overall efficiency in a very positive way.

[FR4-Pilot]

Thanks for the replies Dennis & MotorRotor

Yes, the YEP ESC has active freewheeling, which I'm testing to see how well it works - so far looks good, very good. I haven't tried turning the governor on yet.

[FR4-Pilot]

So these two 3S 2200 35C lipos (in series) are working phenomenally. I changed from the stock 520mm wood blades to my Edge 523mm mains and 72mm tails and kicked the flight times up a notch while dropping power consumption.

Here's flights 5 and 6, with flight times of 5 and 6 minutes, respectively. RPMs in the 1500 range of course.

Flight#5: 1139 mAh put back in! 13.68 Average Amps. 304 WATTS! Estimated max. flight time of 7 minutes 43 seconds.

[ame]http://www.youtube.com/watch?v=yXWeTLsOD5A[/ame]

Flight#6: 1470 mAh put back in. 14.7 Average Amps. 326 Watts. Estimated max. flight time of 7 minutes 11 seconds.

[ame]http://www.youtube.com/watch?v=3hYFyQ2Lrvc[/ame]

There was plenty of wind and cold temps during these flights

These nano-tech batteries, YEP ESC with active freewheeling, EDGE blades, and Swift 16 are an awesome combination.The heli's power setup not changed - 800kV motor, 12T pinion, 96T main gear, 75%-82.5% throttle curves, governor not enabled, and of course the two 3S packs in series.

***

[phoenixheli]

Your setup is coming along quite well. The best amp draw I had was about 21A average with the same motor/gear setup. If I remember correctly, the lowest hs I used was 1700. The packs I used were fairly old and with new ones, the internal resistance is probably much better.

[FR4-Pilot]

1300 RPM Forward Flight (with a two-3S-2200mAh-30C-Lipos-in-series flight pack)

258 Watts !
Century 800kV motor
Century 12T pinion
Zippy 6S pack (two 3S packs in series)
YEP 100A ESC with Active Freewheeling ON
62.5% throttle curve in Dx6i transmitter

The heli handled way better than I imagined it would. I was totally surprised, and very impressed
All power electronics barely warm after the flight.

[ame]http://www.youtube.com/watch?v=d_vLW7Jgvn8[/ame]

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[MotorRotor]

Thanks for the video.

How did you find its cyclic rate through flips and such, or collective response rates through pitch pumps or tick-tocks at that lower head speed?

I found that such head speeds to be fine for my scale flying (e.g. in my Augusta A109A), but rendered the 3D cyclic and collective response to be relatively lethargic.

Basically, the trade off is more flight time (or less expensive/lower mah battery packs) for less response for better aerobatic capabilities.

[FR4-Pilot]

I don't know yet how slow it rolls or flips - I need to take it higher to try those maneuvers to get a feel and will need to get to a more isolated field for that. I don't want to try that where I've currently been flying, but it's on the list of to do items.

I realize the tradeoff - I also know that I don't always want to fly aerobatic style - especially at the smaller fields around here. Sometimes a slow relaxing flight (performance not being the goal) just before sunset is the ticket, and longer flight times wouldn't be a bad thing Being able to switch from Lo-N-Slow (and still flyable) to aerobatic by just changing a throttle curve is super awesomely convenient ! And, being able to use my existing Mini-Titan batteries (those 3S 2200s I have a dozen or so of) for slower flying is an unexpected treat. No doubt the light-weight of the heli is a major contributor to this.

A pair of 550mm asymmetric SpinBlades should be waiting for me when I get home today - I can't wait to see what kind of flight times and/or lower head speeds are possible with those blades

[FR4-Pilot]

1200 RPM!

Just a clip from yesterday's test flight. Put on a pair of SpinBlades 550mm asymmetricals. Lots of fun for sure. Sounds awesome.

[ame]http://www.youtube.com/watch?v=N1Vf5xw6lwA[/ame]

This is about as far as I'm willing to push the ESC (YEP 100A active freewheeling) and 800kV motor, with 12T pinion running 60-62.5% throttle curve. I'm going to change over to the 9T pinion and raise the throttle curves, then see how low I can go with this heli (RPM-wise).