Increasing Flight Time of Hexacopter

T

Theinventor10

Member
I have purchased a DJI F550 hexacopter kit, however its flight time is only about 4-5 minutes on a 3000mah Flourine 3cell lipo battery pack, I was wondering if there is anyway I can increase the flight time without increasing the batteries which I already purchased two more 5500mah Flourine lipo batteries which will hopefully arrive soon. First I was wondering if I got motors with less torgue would it reduce energy drain on my battery? My current motor specs are 1000KV and my propellers are 10inches long. However I cannot increase my propeller size because the propellers will crash into each other if I do, because of the frame type I have. Also I was wondering if a landing gear is necessary and if propeller guards are necessary because I would like to reduce the weight of my helicopter, finally I was wondering if there is any other way to increase flight time? Please note I use Mission Planner with amp2.6 flight controller, gps, and Turnigy radio controller. If you have any suggestions for me please let me know, or if you have any recommendations.

Picture of helicopter
http://imgur.com/aEHufFS
 

John Doecliff

John Doecliff

Member
I would defitnitely lose the propeller guards. You could lose the landing gear if you think its too heavy. You may want to experiment with a different propeller pitch.
 

T

Theinventor10

Member
I have recently heard about propellers with 3blades instead of 2, since I do not have anothe space for longer propellers could this be a solution as it would be increasing the propeller surface area without increasing propeller length, along with getting propellers with higher pitch maybe since my current propellers have low pitch?
 

John Doecliff

John Doecliff

Member
It could be a solution but I have never seen 10" 3 bladed props before. Hopefully the 5500 mah battery works out well for you. Do you know what your craft weighs and how it compares to other 550's?
 


Motopreserve

Motopreserve

Drone Enthusiast
3 blade props will likely lower your flight time. The advantage most turn to 3-blade for is increased thrust in a given diameter limit. But the added blade, along with the power it takes to spin it will lessen the total flight time.
 



T

Theinventor10

Member
I did some more research on props and I saw the people that got longer flight time with longer props and props with higher pitch also had more efficient motors, with a lower Kv rating and ones with more torque. If I got more efficient motors in the future and put on props with higher pitch and with 3blades would this increase my flight time or am I missing something here? If so should I not get more efficient motors at all or get the motors then and keep my regular props? Finally would 3blade props 10inc diameter be like 2blad props 15inches?
 

Motopreserve

Motopreserve

Drone Enthusiast
You're throwing a few variables around that all play off each other. It might be best to head over to eCalc to see how the relationship between various props, battery cell/size and motors have on one another. As mentioned, it is not always exactly accurate - but it's a great learning tool.

What are the specifics of your build? Whats the all-up-weight (AUW), motor type/brand and which props are you running? Have the props been balanced?

Also, I believe you may be out of luck with the 3-blade you posted, unless they all have a puller prop.

Give us some more details and we will be able to help you a bit better.
 

T

Theinventor10

Member
Here is a full list of parts:

Battery components:
#1 3000mah 11.1volt lipo battery Deans connector
#2 3000mah 11.1volt lipo battery Deans connector
#3 5500mah 11.1volt lipo battery Traxxas connector <just arrived>
#4 5500mah 11.1volt lipo battery Traxxas connector <just arrived>
#5 Imax b6 Lipo balance charge and necessary deans battery connector cable
#6 Traxxas to Deans connector <arriving soon>
#7 Traxxas parallel connector <arriving soon>

Flight Controller components:
#1 Turnigy radio controller
#2 Turnigy radio receiver
#3 Gps/compass module for apm2.6 flight controller
#4 apm2.6 flight controller
#5 Radio Telemetry for Mission Planner/apm2.6 flight controller receiver and transmitter 433MHZ
#6 6 Jmt 30amp 2-4cell lipo battery esc
#7 A2212/13t 1000kv motors/ these motors http://www.amazon.com/dp/B011I212LE?psc=1
#8 10inc propellers that look identical to these http://www.amazon.com/dp/B00OC8V5XC?psc=1

Other components:
#1 F550 frame
#2 prop guards
#3 landing gear
#4 screws and other parts/ zip ties and more



I hope this helps, also im not sure what a puller propeller is, well unfortunately I would have to say I never knew propellers had to be balanced, im not sure if they come balanced or if that is something you need to do? Could that be why im getting low flight times? Also the props are a bit damaged on the tips. Weight is approximately 2.5pounds without battery<sorry don't have a very accurate scale>. Hopefully there is a way I can increase flight time and thankyou for your help everyone.
 

Motopreserve

Motopreserve

Drone Enthusiast
Unfortunately, those motors seem a little "generic," considering that's the title of the page itself :).

No way of knowing what type of thrust they are providing unless you test them yourself. You could do a google search of other 2212 1000kv motors and try to get an estimate.

The props certainly need to be balanced - even very expensive ones. You need to grab a prop balancer. Dubro makes a good one. If the tips are broken, you are likely losing potential thrust, whatever that thrust may be. This will effect flight times. If you're chipping them due to crashes, might be best to get some cheaper composite props by APC or HQProp. They will stand up to a bit of haphazard flight.

Honestly, I think your best bet would be to get some decent quality motors. Many mentions on this forum of good options - and even DJI makes a propulsion kit for their f550 I believe. That way no guessing - and you'd certainly be getting FAR more flight time that 4-5 minutes.
 

T

Theinventor10

Member
I've been looking at good quality motors and they seem kinda of expensive, I was wondering if anyone knew any fairly good quality motors for a good price? Also just how much increased flight time would I get? For example if I got 750kv motors how much better is that then 1000kv motors?
 

Motopreserve

Motopreserve

Drone Enthusiast
Expensive is subjective. There are super cheap motors, like the ones you have. But they perform as expected, less than ideally.

I've had great experiences with sunnysky motors for reasonable prices. They also make several models that would be appropriate for your hex size.

Ecalc will help you get an understanding of the various effects for the different options.

Also, what are the specs of the batteries you are using? I saw mention of traxxas - which I only know of as an RC car/truck manufacturer. They may not have the appropriate thrust/weight ratio for these mumtirotors.
 

T

Theinventor10

Member
Flourine is the battery brand I use. Traxxas is just the connector on some of them which I got a Traxxas to Deans connector because my helicopter cable I put on is a Deans connector, the batteries only came with Traxxas connector at 5500mah.
 

Motopreserve

Motopreserve

Drone Enthusiast
I've never heard of flourine. You might want to head over to the thread that @Bartman wrote that explains all the in/outs of these lipos, if you haven't already. Great info.

If you're using Deans connectors - you can just solder those directly onto the battery. Have to be careful and do one wire at a time. That way you're not introducing another possible failure point at the main source of power to the craft.

Also, C rating (discharge rate) of these batteries?
 

T

Theinventor10

Member
Flourine lipo batteries I use are 35c discharge rate, I already checked out this website when I was considering my lipo batteries: http://www.rogershobbycenter.com/lipoguide,
it has a lot of detailed information on lipo batteries, but I will go ahead and take a look at the thread you suggested in case I missed something.

Also these are the exact lipo batteries I got:

http://www.amazon.com/Floureon-5500...825800&sr=8-4&keywords=5500mah+lipo+batteries

and,

http://www.amazon.com/dp/B00L2V09VQ?psc=1

You are proboly wondering why I got lipo batteries with Traxxas connector but that is because they were cheaper then buying 2seperate deans connector packs. For me I think Flourine is proboly a good balance between price and quality.
 

Motopreserve

Motopreserve

Drone Enthusiast
Not sure what you mean by "two separate dean connector packs," but I would suggest that you replace the Traxxas with a deans on the battery - so there are only 2 connectors, and no turnaround to deal with the traxxas plug. Raw deans plugs are cheap.
 

John Doecliff

John Doecliff

Member
A 2212 motor thats around 1000Kv seems right for that application. I have them on my flamewheel 450 and thought I could just change the frame and add 2 more (2212's)to make it a hex. The DJI 2212's that I have are 980 Kv I believe. So maybe you could do better but I think your where you want to be with a 10" prop and 2212 motors. I do agree that 4-5 minutes is a low flight time and something is amiss. Just to confirm because this happened in another thread, your batterys are fully charged to 4.2 vdc per cell or 12.6 vdc overall? Imbalanced props shouldnt have a huge effect on battery time. I think a 5500mah battery would be perferred to a 3000. Im not sure about the weight, it's probably no different then most frames but just to clarify again, what frame is it?
 


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