Need long flight times

kloner

kloner

Aerial DP
that's fine, but that's a consistent number that it becomes like leaving a light in 3rd gear....

The part about these things breaking up cause they can hover an hour in wind is crazy..... Efinerrz here has well past an hour and the things u8 on a cf frame similar to a cinestar.... the discos are doing 53 minutes and 30 kilometers, believe me, that's windy to cover that distance. MR's have come a long ways.

We have a big lifter coming out that carries dual reds and flies them 32 minutes at hover. The overhead is your friend and hovering throttles tickling the limits is how we do it. on all size airframes with all different payloads...

we run 450 size airframes with up to 16" props.... when the throttle gets down past 35 we hit walls.... it is my benchmark number to stay over
 

R

R_Lefebvre

Arducopter Developer
Any links to those machines? I'd love to see what they've done. 53 minutes with a payload is pretty amazing.

What I'm talking about are things like this:

View attachment 18055


Somehow that guy managed to claim an official world record at 1 hours 20 minutes.

Those motor mounts are actually glued and zip-tied to the tubes. And look at the motor wiring, 24 gauge or something. The thing is ridiculous, but this is what some guys are doing.
 

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R_Lefebvre

Arducopter Developer
Hmmm... hard to glean much info from that thread.

Yes, Panasonic 18650B LiPo's are the standard for long duration flight.
 


kloner

kloner

Aerial DP
theres a lot of people with alot of questioins, but that is where this "kit" is developing. it will be a rtf kit in another month

Pretty sure there on gens-ace, effinerz a member here is the MAN on efficiency around here to the best of my knowledge

They have gone through 13 motor winding configs, there is a major milestone coming shortly that is a 30 km flight to macao from Hong Kong and back..... on that no big deal kit....
 
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R_Lefebvre

Arducopter Developer
Hey, 60km starts to be a big deal. So I will love to see it when you do it. 25 minute at 60 km/h is pretty good, you're right, I shouldn't have dismissed that. My 500 heli does 20 minutes with an SX260 on board.
 

G

gadgetware

New Member
kloner said:
... in transition to changing over to all kde gear, hoping for more efficiency and performance....
Click to expand...

Curious how accurate the KDE manufacturer charts are. I'm looking to build a hex rig that's about 9000 grams total w/ batts (2x 6S Maxamps 11000 mAh) and based on the charts using a 4012 motor I calculate a 30 minute flight time with 16" props. Obviously that's not the real flight time but just trying to figure out how far off it is.
 

kloner

kloner

Aerial DP
you will see that in perfect conditions, then wind, another lbs or two, etc change things, never better unless those parameters include weight loss,,,, that seems to be the big factor that really makes a huge difference in efficiency. With enough overhead you can really tickle some sweet spots, but grams over a certain level translate exponetionaly to the loss of efficiency reaching deep down into the perfromace side of things.

I can tell you this, I've ran 3520 and 4014 kde on the same exact airframe and hovering the 3520 was about 4 amps less than the 4014 and that was a 12.8 amp hover vs 8.8 amp hover on identicle airframes at identical weight..... 6s.... the same exact frame but 2814 on 4s hovered at 22-24 amps and i could get it into 60+ amp relatively easily....fff of course
 

FerdinandK

FerdinandK

Member
If prop/motor/esc-data is available, the pediction of the flighttime can be done pretty accurate. Not all conditions make thins worse. To hover in calm air is not the most efficient status on multicopter, if you can hover for a certain time, you can fly longer at moderate forward speed (20-30km/h). Of course fff is more expensive, so 60km/h for 1h is pretty good.

Here one of my last results,
47min with 2kg payload in 20-30km/h wind.

best regards
Ferdinand
 
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R

R_Lefebvre

Arducopter Developer
Ferdinand, thanks for posting! You are the man. I was trying to remember your name because I know you had a quad that's flown a long ways too.

I've never seen that X8 with the camera before. That's simply amazing performance. I've never seen anything like that, or even close. Proof of what you can do with science and engineering.
 

Carapau

Carapau

Tek care, lambs ont road, MRF Moderator
And deep pockets!!!! At about £600 per prop/motro x8 that is an expensive rig but then the performance is pretty out there.
 

FerdinandK

FerdinandK

Member
@Carapau
If you do the math correctly (propellers are in pairs) and apply the correct currency-conversion the price per motor/prop is about half of your estimation.

Of course you can do something similar with smaller propeller and smaller motors, but then the flighttime is only 30min.

or you can scale down the payload, then the flighttime will increase accordingly.

There is no magic behind flighttime, range, it is just physics, but most people tend to ignore that.

That you need matching and correct Motor/Prop/ESC is mandatory (e.g. raising the voltage to become more efficient is a typical legend, a fori-tale)
Weight is most important, if we do not touch the payload, the frame the wiring and the placement of components remains, especially what people like as "neat builds" is something, where you can shave off weignt.
Battery is most important in type and mass, with small battery you get small flightimes, with "high discharge" batteries you get waste flighttime, you could have used a "high density" battery instead. 5C-average (and real) discharge rate is enough for 12min flights, there is no advantage having 60/90C stickers on the packs. As the mass of the battery is concerned, you should aim 1:1 (battery to copter) or 1:1:1 battery:copter: payload. At 10kg AUW you will not fly for long with 1kg battery (even with most efficient propeller/motors)
Heat is your enemy, what gets warm looses energy, so you should aim cool components (< ambient +10/15°C) an 80°C Motor after flight is for sure a NOGO, what is cool, needs no cooling.

But the most important point is to open your mind, and believe that flighttime of 10-20 min are NOT kismet, you have control over your flighttimes, everything is possible. If you start with that, the rest will follow.

best regards
Ferdinand
 
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sk8brd

Member
Ferdinand- Question--when your calculating your predicted flight times manually no ecalc how much does the actual amp draw differ when you have a gimbal/fc/esc's, fpv pulling off the batt compared to predicted amp draw by just using weight and spec sheets provided by motor manufacture. Say for instance tiger spec sheets tells me i can hover at 50% throttle using 30amps on 15inch props-(not my real numbers here just using as example) How much more amp draw will be used to account for a gimbal/fc/lights/fpv etc energy usage. Is there a number you use to get more accurate predictions or just go by what spec sheets tell and your auw weight. I know you can use a watt meter to test each component but i'm talking about predicting flight times before you have any components available. Do you just add say an extra amp into the hover draw to account for extra energy use or figure out how many mah the component will pull for a given amount of time then subtract it from the available mah on the batt?
 
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FerdinandK

FerdinandK

Member
@sk8brd
I am using this .xls which is based no a formula derived by a mate unfortunately his blog if offline ( www.flugst0ff.de )

Here you enter the parameters of the copter and the efficiency is "matched" if you have experience with the propeller ( /motor/esc) you can take that from other copter. Here the flighttimes can be predicted very accurate.

If you gimbal, ... draws significant amount of energy something is wrong, Even the Zenmuse Z15 almost takes nothing (compared to the motors), the same is valid for VTX. (Assuming it is a copter and not a flying floodlight)

best regards
Ferdinand
 

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sk8brd

Member
Thanks Ferdinand. I read a post about a guy getting 2 additional minutes by using a seperate small lipo for his lights rather then using the main. Not sure how many lights he was using but that seems like a big difference for just lights. I lost about 4 minutes by adding a gopro and zenhero to my small craft so loosIng 2 minutes for lights alone seemed strange.
 

FerdinandK

FerdinandK

Member
If you add a GoPro on gimbal you will loose the time because of the additional weight, not because of its power consumption. How you get more flighttime by adding an extra battery is not my expertise. Let me add, that if something on a brushless gimbal gets hot, something is wrong, or should be done different.

best regards
Ferdinand
 

H

haha49

Member
FerdinandK said:
If you add a GoPro on gimbal you will loose the time because of the additional weight, not because of its power consumption. How you get more flighttime by adding an extra battery is not my expertise. Let me add, that if something on a brushless gimbal gets hot, something is wrong, or should be done different.

best regards
Ferdinand
Click to expand...

Tarot 2d gimbal draws a max of 1 amp. I lost 1:30 adding it. I los 1:00 adding the gopro, mini osd, and boscam 5.8 ghz vtx. Then the landing gear took 1 minute off as well so my total lost time was 3:30 seconds.
 

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