I've been performing some flight tests using two batteries and I'm just not getting what i was expecting. I am hoping other Y6 users can chime in with their battery/flight times, and see if i'm really off.. or if this is what is expected. Lastly, most importantly.. what can I do to increase flight time? It would be a goal of mine to achieve 20minutes.

Battery 1: Turnigy nano-tech 5000mah 3S 25~50C Lipo Pack

Approx 8minutes.

Batttery 2: ZIPPY Flightmax 5800mAh 3S1P 30C

Approx 10 minutes.

Using 850kv 3DR blue motors. Long Range Telemetry module. Dragonlink for Radio. Carrying Tarot 2D gimbal (+200g) no camera for these tests.

Attached images of flight times and VCC/volt data.

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Hey Raph, what is your battery failsafe set to? I will try to replicate it here, and do some tests on my machine. I see that you are going really low, to just below 9V. That is a dangeously low area. I posted my last battery7 data in the Y6 group for you.

Hi Wessie. I actually have my failsafe

Sorry Raph, I dont understand your last post.

Weird didn't post properly. my apologies

meant to say - my fail safe is usually at 9.5, but for the above tests I turned it off to see how low I could take it. Also, it's dropping below 9.5 under load.. so after the above tests, when I plugged the batteries in to charge they read 10v (before charging)

Ok I will turn mine off too, and let you know what i get from fully charged to 10v in a hover.

@Ralp or Wessie,  have you tried running the numbers through ecalc to see if it is close?  Im not sure how well a Y6 vs hex compare for efficiency.  http://www.ecalc.ch/xcoptercalc.htm?ecalc&lang=en

 

What is your thrt value at when your are hovering?  you might be able to go up a prop size to increase your hover time (but decrease your max thrt time)  ecalc can give you an idea how this changes.  Just be sure you do not exceed your speed control, motor, or battery current limit.

 

If you do change your prop size, don't forget to redo your PIDs and hover point.

hi Dennis - thanks for the input. I have tried ecalc, attached are my results. Let me know if I inputted anything terribly wrong. It's saying 22 min hover time - definitely not getting anything close to that.. about half actually.

my Thr value is at 505 when hovering. I'm not sure exactly what that number means (505 out of?), so forgive my ignorance.

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Hi Raph

First I have to say that I believe any X2 config is inefficient. Only reason I would use it is, if you need redundancy.

why i don't like it is simple. The prop inside the stream of air is not doing the work it should but adds the full weight for motor, esc and cables to the config. Only way to go around that is to add a bigger prop to the bottom motor. You have to test that as you get no reliable number for power consume and thrust rate of such a setup. if you want to fly 20 min, make it a Tricopter.... you loose all redundancy... but gain quite a bit in weight you remove... so flight time.

Important is the prop you swing... there are huge differences to prop size/pitch, how efficient the motors power consume will be compared to lift. Slow flyer are best at 50% throttle and suck over 80%. E-type on the other hand get good over 70%. Depending how you fly and what pos is hover for your gear, choose your prop. Balance each prop, get good props!

All will add to make your craft fly smoother.... if you don't reach 20 min on indoor hover, you should rethink your concept... depending on weather... we tested a quad and hex in a good 25 knots wind on loiter.. the quad had 50% flight time drop due to heavy wind corrections... so how you measure... will change your results in flight time.

Cheers

J

Hi J,

Thanks for the insight! I'll definitely take into consideration the different prop types.. something to play with

 3DR's Y6, which I am using does have bigger props on the bottom and smaller on top (11"/10" respectively). They boast a 10-15% efficiency loss with the Y6 configuration, but who knows for sure. I really can't imagine using a remote control flying lawnmower without some sort redundancy.. so definitely is key for my peace of mind. 

Before the y6 i had a 3DR quad configuration with the same motors and 10" props. The difference in flight time was 2-3 minutes depending on 5000mah/5800mah. could this be correct?

I get about 10 minutes taking 6000mAh out of my 8000mAh 3s bats, mine is about 2500grams with graupner 11x5 props.

I think 8 minutes with a 5000mah batter is very reasonable with a Y6. I have a quad and get about 10-11 minutes flight time with my 5000mah battery and I have the alarm set at 10.5 volts.

 

If you're getting 8 minutes (.133 hours) with a 5ah battery then you are pulling about 5/.133=37.5 amps or 6.25 amps per motor which sounds about right. I didn't take into account the Peukert number but this would lower the estimate.

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