I Need More Flight TIme - How???

[teecee]

I have a new Carboncore Hex (specs in sig) but in this cold (-5 to -10C) I am only getting around 2.5 minutes with camera and gimbal before first level voltage protection LEDs kick in. Very frustrating as I hope to get far more flight time. I am going to add telemetry to monitor on board power more accurately but there has to be more to this. Some say bigger mah batteries. I currently have 2 X Hyperion 6S 35C 5400 mah. Should I be looking at 10,000mah+ batteries or??? What else can I try?

 

[jes1111]

Less weight, more efficient motor/prop setup, more battery. Given that you probably can't do much about the first two, the third is your only option - but there is a "law of diminishing returns" on adding batteries since they themselves are heavy.

Best is to get familiar with eCalc

 

[jbrumberg]

A koozie for your batteries to try to keep them warmer. Cold lipo's discharge very rapidly. Some hints on cold weather operations: http://www.multirotorforums.com/showthread.php?16449-Lipo-Use-in-Cold-Weather

There are all kinds of things to consider with cold weather flight operations.

 

[jes1111]

Oops - sorry - I skipped the temperature part of your question - as jbrumberg says - keep your batteries warm until you are ready to fly - I carry mine in a fireproof case which, coincidentally, provides great insulation. Alternative would be a regular picnic coolbox.

 

[Bartman]

I have a new Carboncore Hex (specs in sig) but in this cold (-5 to -10C) I am only getting around 2.5 minutes with camera and gimbal before first level voltage protection LEDs kick in. Very frustrating as I hope to get far more flight time. I am going to add telemetry to monitor on board power more accurately but there has to be more to this. Some say bigger mah batteries. I currently have 2 X Hyperion 6S 35C 5400 mah. Should I be looking at 10,000mah+ batteries or??? What else can I try?

those are some big honker motors....what props are you using? the voltage protections may be screwing you up...if you absolutely want to use that feature then I suggest you look at those settings more closely. what are your pack voltages at when you end a flight? 3.7 or more like 3.9?

 

[teecee]

those are some big honker motors....what props are you using? the voltage protections may be screwing you up...if you absolutely want to use that feature then I suggest you look at those settings more closely. what are your pack voltages at when you end a flight? 3.7 or more like 3.9?

I am using these props: http://www.rc-drones.com/gemfan-rcd15x5.php
I will start to track voltage at the end of each flight and report back.
This is what I get in eCalc...
View attachment 16331

 

[gm1]

Not sure about the A2 but the default voltage on the NAZA alarm is a volt too high. If you go in Assistant and set the voltage down, the flight time more than doubles before the alarm comes on.

 

[Quinton]

You really need to get some kind of telemetry set up to know exactly how many volts you have.
I have a Skyjib hex which is 1.5kg heavier than yours, ecalc gives me a hover time of 12 mins with my setup. (When I enter your props and motors on mine I get 9.7 mins)
I am getting 10 with the Zen 5D and 2X 8300 mAh lipos, 7 mins with 2 x 6200 Mah
I have 10.4A lipos as well, but I find the sweet spot to be the 8.3A lipos

I don't rely on the voltage level protections at all, i just land when it gets to 22v.

If you have a T14SG and a R7008sb rx you can buy a cable for a couple of dollars to set up voltage telemetry which is much better.

 

[sk8brd]

tecee- some things to consider for flight times, your lighter then a s800evo w/ a gh3 setup. the 5d setup weighs a little more but with a 6s 10k mah you should be close to 10 minutes. what is your throttle percentage at hover at in manual mode? make sure you voltage settings are correct on A2. one 5400 batt is not enough for any decent flight time at this weight. if i run an ecalc i get close to the times your reporting on 1 5400 batt. the hover amp draw w/15x5 is being reported at 70 amps at hover- that is very high. keeping everything the same and switching to u5 motors lowers amp draw to 57.92 The results that people are reporting w/u5's are even better then ecalc reports and flight times are not 100 percent just a guide-keep in mind.. if your hover at throttle is around 70 percent then there is the problem, to get closer to 50% which is ideal you will need 16X5 props. Another thing is your esc's are too big and are costing you weight. you motors at max amps produce less then 30amps w/ 15x5 props. a 40 amp esc will be more then enough and will save you over 100grams compared to the 55g weight of maytech's -not a huge deal but something to consider. run 2 5400's on 16's then report back your hover and flight time and batt usage and i can calculate your amp draw then we can see if other motors will get you better flight times. i am in the process of building a 950 as well w/ a gh3. Same setup as you but u5 motors or kde motors and 40 amp esc's. changing to 16X5 prop with two 6s 5400's will get you in the 50%hover range and close to 9-10 minutes. you have to test of course cause e -calc is off flight times and just a guide.

 

[Quinton]

Its pretty hard to get hold of the U5s Ive seen, I am using mt3515-15 along with 40A optos which is pretty close to them, but I would get the U5s if available.
I am also running 16x5.4 T-Props, I have just ordered the 16" Xoars to see how they will compare.

I posted some info the other day on tests I did with these motors/props which may help..

T-Motor 15x5 Props

25% 25.6W 1.11A 270g Thrust
50% 95W 4.2A 900g Thrust
75% 315W 14.0A 2000g Thrust
100% 480W 21.23A 2800g Thrust

Xoar 15x5 Props

25% 24.4W 1.05A 180g Thrust
50% 86W 3.75A 595g Thrust
75% 293W 13.11A 1600g Thrust
100% 434W 19.8A 2430g Thrust


T-Motor 16x5.4 Props

25% 25.5W 1.11A 355g Thrust
50% 110W 4.8A 1060g Thrust
75% 350W 15.3A 2370g Thrust
100% 536W 24.3A 3200g Thrust

 

[teecee]

tecee- some things to consider for flight times, your lighter then a s800evo w/ a gh3 setup. the 5d setup weighs a little more but with a 6s 10k mah you should be close to 10 minutes. what is your throttle percentage at hover at in manual mode? make sure you voltage settings are correct on A2. one 5400 batt is not enough for any decent flight time at this weight. if i run an ecalc i get close to the times your reporting on 1 5400 batt. the hover amp draw w/15x5 is being reported at 70 amps at hover- that is very high. keeping everything the same and switching to u5 motors lowers amp draw to 57.92 The results that people are reporting w/u5's are even better then ecalc reports and flight times are not 100 percent just a guide-keep in mind.. if your hover at throttle is around 70 percent then there is the problem, to get closer to 50% which is ideal you will need 16X5 props. Another thing is your esc's are too big and are costing you weight. you motors at max amps produce less then 30amps w/ 15x5 props. a 40 amp esc will be more then enough and will save you over 100grams compared to the 55g weight of maytech's -not a huge deal but something to consider. run 2 5400's on 16's then report back your hover and flight time and batt usage and i can calculate your amp draw then we can see if other motors will get you better flight times. i am in the process of building a 950 as well w/ a gh3. Same setup as you but u5 motors or kde motors and 40 amp esc's. changing to 16X5 prop with two 6s 5400's will get you in the 50%hover range and close to 9-10 minutes. you have to test of course cause e -calc is off flight times and just a guide.

I actually do have 2 X 5400 lipos on there. Will try 16X5 props and possibly 8-10,000 lipos and see what happens. The U5-400's might be worth considering too...

 

[Quinton]

I actually do have 2 X 5400 lipos on there. Will try 16X5 props and possibly 8-10,000 lipos and see what happens. The U5-400's might be worth considering too...

Just make sure you have the extra inch in between your props at the moment
You will notice a bit more heat in the ESCs and motors with 16" props.

 

[sk8brd]

Hey Quinton, nice info! i believe the 3515 have the same specs as the u5 performance wise so i think performance would be the same. u5's are out of stock where ever i look. i hear a lot of people like the xoar's curious to see performance vs the t-props.

 

[sk8brd]

tecee-if your running 2 batts i would check your voltage settings and make sure your battery's are ok. you could be getting voltage sag due to tired batts. i think the 16's w/help. those motors have some serious lift power but just check the motors after flight make sure there not too hot. on the 950 frame 16's fit ok i believe. you auw weight is not bad and lighter then similar s800 setups i would think you would get decent results like flight time even on 2 5400's. in the end if all is good with batts and voltage settings then props size and motor will make most difference. i'm sure you could sell the motors if you want easilly- a lot of cinestar heavy lift octo guys are running those motors just check out the freefly forum.

 

[sk8brd]

quinton- judging by your numbers and flightime assuming you flying with 20% capacity left in a linear draw like a hover it looks like you using about 13amps per motor-if my math is right of course..lol if we look at the u5 chart specs w/ 16 props and on 6s and look what 13amps lifts per motor is it's 2120 grams of thrust. if your auw is 9437g then you only need around 1572 grams lift per motor. on the u5's you can lift 1750g per motor with an amp draw of 9.4 amps w 16's props. So your amp draw will be less then 9.4 per motor cause you don't need to lift 1750g per motor.. Even if you were lifting 1750g per motor it would be less then 13 amps per motor. This is why ecalc is off on u5 motors i don't think the thrust per gram was right in the software. A guy on a cinestar got 21 min on a 24lbs octo w/ u5's that includes the simulated weight of an epic with two 6s 10k's i checked his gpx file cause he's on mk and it was true. he nearly doubled what e-calc was predicting of 12min and his hover was over 62%. i'm trying to sort this all out for my build..

when we look at the kde 4012 motors the numbers are even better less then 7amps per motor roughly for 1645 grams of thrust. any way- the predicted flight time with u5's with 9amps draw per motor is 14minutes. keep in mind that your amp draw will be less so even better time. the t motor spec sheet doesnt show exactly what the amp draw will be at your exact weight per motor so this flight time is conservative i'm using closest heavier number. on the kde motors at 7 amps draw per motor would be 18 minutes, but really better cause i don't have exact spec for your exact weight so the numbers are assuming you weigh in at 9.8kg. the kde spec is with 15' props btw. the required thrust per gram for your weight was closer to exact amp draw on kde spec sheet on 15's so i went with the closet heavier number as well. now if these numbers work in real life gotta test i suppose but theses flight times are assuming your only using 80% of the battery so they should be close as long as my weight of your copter was right.

if i use 13.6 amps per motor then i get 10.4 min with your current setup. do you have 20% remaining batt life after flight or used about 13,280 mah in that 10 min on the dual 8300's ?

 

[sk8brd]

tecee- when i calculate your numbers and amp draw for your motors you should be getting 10 minutes on two 5400's-easy. i was calculating before with two 4500's--error on my part. calcs are based on t-motor 15's. make sure voltage settings are right. i have a feeling that it's not calibrated to a fully charged battery,

 

[Quinton]

if i use 13.6 amps per motor then i get 10.4 min with your current setup. do you have 20% remaining batt life after flight or used about 13,280 mah in that 10 min on the dual 8300's ?

Wow my heads sore after reading that

I am very conservative, I always land at 22V under load (which goes up to 22.5V without load) and after charging I put back in 5200 mAh / lipo so just over 37% left.

 

[teecee]

tecee- when i calculate your numbers and amp draw for your motors you should be getting 10 minutes on two 5400's-easy. i was calculating before with two 4500's--error on my part. calcs are based on t-motor 15's. make sure voltage settings are right. i have a feeling that it's not calibrated to a fully charged battery,

OK, newbie question... How do I do this. I have been on that page in the assistant but I have always just pressed "calibrate" when I have a full charge.
Cancel that.... Just read the sidebar and did what it says to do. Will test and report back.

 

[sk8brd]

sorry Quinton when i looked at the kde motors i got a little excited lol.

 

[Quinton]

Ok the 16" Xoars came, anyone interested here is the results with the 4 of them for comparison they seem pretty good.
Will be interesting to see how they fly.

T-Motor 15x5 Props

25% 25.6W 1.11A 270g Thrust
50% 95W 4.2A 900g Thrust
75% 315W 14.0A 2000g Thrust
100% 480W 21.23A 2800g Thrust

Xoar 15x5 Props

25% 24.4W 1.05A 180g Thrust
50% 86W 3.75A 595g Thrust
75% 293W 13.11A 1600g Thrust
100% 434W 19.8A 2430g Thrust


Xoar 16X5

25% 27W 1.15A 310g Thrust
50% 102.5W 4.5A 910g Thrust
75% 335W 14.5A 2070g Thrust
100% 510W 22.1A 2950g Thrust

T-Motor 16x5.4 Props

25% 25.5W 1.11A 355g Thrust
50% 110W 4.8A 1060g Thrust
75% 350W 15.3A 2370g Thrust
100% 536W 24.3A 3200g Thrust