Jun 08, 2013, 06:33 AM
Registered User
300 grams 12Ah... verrry rrrreliable
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Jun 08, 2013, 08:14 AM
Registered User
EndOfDays's Avatar
@KWE
You have to look for the NCR18650B
NCR18650 -> 3100mAh
NCR18650B -> 3400mAh

If some other brands or types of batteries can be used, you have to find out. So if you order one pack, would be great if you share your experiences with it.

best regards

Ferdinand
Jun 08, 2013, 09:12 AM
Hamburger
hamburger's Avatar
anyone got experience with the tx lipos mentioned earlier? Are the specs reliable?
Jun 08, 2013, 09:32 AM
DJI Supporter
Sid3ways's Avatar
I'm hoping to find the sweet spot for a quad with a brushless gimbal to carry a Sony A65. I will continue to follow this thread and thank everyone who continues to contribute information!
Jun 08, 2013, 09:33 AM
Suspended Account
@renatoa
Higher pitch causes unwanted roll effect at 3D flight if you change the throttle fast.I guess it is the reason for 3D flight.
i find a thread about this.i also fly 3D . https://www.rcgroups.com/forums/show....php?t=1446206

@EndOfDays
i know the every props has got the different RPM which is most efficient and KV means rpm/v so here is what i understand(please correct me if thats wrong);
if we add some more payloads(like powerful motor,larger capacity battery,fpv parts) we need more rpm to hover so we pass the most efficient rpm range for props and our flight time decrease(turbulent flow on props), we cant add more payloads for a known motor,voltage and prop combination. right?

for motor ''kv'', we want motor with lower kv and high poles that means we get higher torque from motor and use larger props on it. So high torque motor can drive the larger prop very efficient.if it heats it's on heavy load(larger prop)

With all these assumptions i assume that there is different propeller airfoils which has different rpm range to drive efficient and max. efficient even if they have same length and pitch.
if i am correct , we should test one props (which is know totaly efficient others) and find out which paramaters are in harmony.
i could test the props at our student lab. and will share here when i receive my orders from foxtech.
Jun 08, 2013, 03:27 PM
QUAD-A-HOLIC
MOFO64's Avatar
Okay got my 360Kv motors and 15.65 props. Carbon fibre frame parts will be here this week. Will get larger props soon. Batteries are next.

Thanks again for this thread EOD

Jun 08, 2013, 04:30 PM
Registered User
EndOfDays's Avatar
@whiterabbit62
The efficiency just gets lower, the more load a prop/motor has to carry, the curve is monotone but nonlinear. So if you can lower the rpm (e.g. by less weight) you gain flighttime not only because of less weight needs to be carried, but also because of a better prop-efficiency, and possibly loose by a worse motor/esc-eta. Typically the prop-eta is the dominant part. You can always add payload (and get less flight-time) as long as you can take off with the weight (it is a reasonable setup).

Most of propellers we use are RC-propellers designed for airplanes, and they work quite well (e.g. the Graupner) the "typical" multirotor-props are nice for hovering, as they try to maximize thrust (but not efficiency). The optimal prop for endurance on multirotors is a prop with a diameter: pitch ratio > 2:1, high (very high) aspect-ratio, and possibly a thicker profile. So the Graupner would be a good point so start a CFD-optimization (I might start such a project someday). The problem with the Graupner-Props is, that 14x8 is the max size available as we need them CW and CCW.



@MOFO64
Nice quad, you got the message. If I can just make one comment, if you put the ESCs on the arms they get cooling directly from the airflow, and you are able to keep the wires shorter. I am sure you can get 50gr by that.

best regards

Ferdinand
Jun 08, 2013, 08:56 PM
Suspended Account
Thank you for these informations, Ferdinand!

For CFD seems like forever.I gonna use some energy equations and termal imagining to find out whats going on.Experimental methods are faster(cost more but its ok)

Have you tried 14x8 Graupner vs 17x5.5 from foxtech with same AUW-motor?

You have 50.5min flight time with 17x5.5 props and 39.4min with Graupner(NX4006 -from your exel datas) there is 100g difference in AUW but i guess graupner need more voltage because of 11min is slightly high for 100g difference.

You have replaced the motor for a 17x5.5 props with more torque motor and flighttime increase to 95min but AUW is changed to 1480g.it's hard to figure out which is more effective , lots of variable changes at the same time in these setups.
But you simply explain them,Thanks for this.
Jun 09, 2013, 01:19 AM
Registered User
EndOfDays's Avatar
@whiterabbit62
The xls-sheet is more a working sheet (to try out how the flighttime changes). The first rows are matched to the Graupner 14x8 / NX 4006 530KV setup, the battery entered is a maxamps.com (4S11000 Lips 11000 useable, 850gr), in the second setup it is the current one with the 17x5,5 props and the 390KV motors, here the battery is the Panasonic (4S4P NCR18650B 13600 nominal, 12500 useable, 770 gr)

If you compare with the same battery it is 45 to 50min (with 700gr payload on a quad)

The other lines are just what would happen if you scale up to a hex, octo, dodeca, hexdeca, the frame-weights are what I build and tried for the Graupner 14x8/NX 4006 setups, and this can also be done for the 17" setup.

For the 14x8 you need a motor with approx 500-600KV on 4S (for the range of 250-550gr a motor)
for the 17x55 you need a motor with approx 330-400KV on 4S (for the range of 250-550gr a motor)

best regards

Ferdinand
Jun 09, 2013, 01:52 AM
I Like Popcorn
flylite's Avatar
EndOfDays,
Thank you for such an inspiring thread - very informative and I hope you continue to get awesome results.

I was wondering at what % of throttle you get a stable hover on your quad (without FPV equipment), with the Naza in Atti I expect its 50% but on manual?

I have ordered some 17x5.5's to follow along and replicate your findings.

Kind regards

James
Jun 09, 2013, 02:22 AM
RC pilot by soul
Quote:
Originally Posted by EndOfDays View Post
Here a pic of my FPV-Module added to the quad:




@MOFO64
Hobbywing escs are compatible, as far as I tried, I could not get any ESC with simonk to run with these motors, big props and 4S. 66min is a great endurance, keep on pushing!


best regards

Ferdinand

what do you mean they are not running? no spinning at all ?
Jun 09, 2013, 03:02 AM
RC pilot by soul
Quote:
Originally Posted by EndOfDays View Post
update ...
current highscore: 95min46sec (video above updated).

@solars
The 14x8 with the NX are a good compromise. If you want to make your life easier, than I would take these motors instead (better mounting options for the propellers)
http://hobbyking.com/hobbyking/store...tor_Motor.html

best regards

Ferdinand
Ferdinand,

1. Can you please post a picture of how you mounted the props to your NX-4006?

2. for a heavier frame and longest possible duration, would you recommend the NX4004 / 14x8 combo on 4S over the RCtimer 5010 / 17x5.5 combo ?
Jun 09, 2013, 04:42 AM
Registered User
EndOfDays's Avatar
@i3dm
They do not start properly, and they do not run properly, so not useable on a multicopter since you cannot takeoff (without a flip), but this is possibly only on the escs I was using.

You will not like the way I mount the props:

but you can use the tunergy motors instead, they come with a prop adapter (on the bell).
http://hobbyking.com/hobbyking/store...tor_Motor.html

If you want to get longer flight-times, with more payload, you should go for "big" frames, but not "heavy" frames, and if the frame is comparably "heavy" you should mount as many motors on it as possible (coax-setup). What motor/prop-compo you prefer, depends on your taste, and if you can afford (in terms of size) 17" props (and okto becomes rather big).
Here is the thread of my X16 based on the NX4006:
https://www.rcgroups.com/forums/show....php?t=1763685

With the 17" props I did no heavy lifter up to now, but for the moment I would prefer the tunergy multi-star
http://hobbyking.com/hobbyking/store...Outrunner.html

Another possible setup would be:
these motors (T-Motors 340KV)
http://www.electronicarc.com/catalog...roducts_id=976
These props (Carbon 18x55):
http://www.foxtechfpv.com/1855-carbo...ccw-p-986.html
which is performing nice on a foldable X8:
Klappfixx X8 Maiden payload test and BL-Gimbal (5 min 35 sec)

here some more information:
http://www.multirotorforums.com/show...-18-quot-props

@flylite
I have not tried so far in manual, but you can fly normal up to 2,4kg with the quad (I have not tested more) with the rctimer-motors, with the tunergy (because of the higher KV) more should be possible.

best regards

Ferdinand
Jun 09, 2013, 12:11 PM
Registered User
Can someone suggest a brushless motor with arround 2000g thrust with 4S(14.8V) battery and 15"x? prop ?

Michael
Jun 09, 2013, 03:48 PM
Registered User
rimshotcopter's Avatar
@EndOfDays, I understand the general consensus is that two bladed props are more efficient than Three or four bladed props, What are your views on this subject?

thank you in advance.


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