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Old Aug 10, 2014, 10:59 AM
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Italy, Lombardy, Como
Joined Jul 2013
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too heavy? need advice

hello
I have just finished assembling a mini quad, taken from bangood: ZMR 250.
will mount the motors: rcx 1804 2400 kw, use a kk 2.15 and I wanted to use (since I already have) a 2200 mha 3s. now I have to get the motors, but I'm afraid that the quadcopter is too heavy. according to you I have to remove weight? or can I leave it like that?

here is the weight with the battery, FPV kit, camera, without 4 motors (add 80 gr)

(518 gr without motors)
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Old Aug 10, 2014, 11:02 AM
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Joined Oct 2013
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Lots of these built over in this thread http://www.rcgroups.com/forums/showt...180331&page=33

Mine with a 1400mah battery but without FPV gear is 444g

Ben
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Old Aug 10, 2014, 11:15 AM
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Joined Jan 2014
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It will fly at that weight - I'm using the same motors and with a 1800 mAh mine came in at 560g, it hovers at 60% throttle. There is enough power to have fun at this weight but I recon 600g is the absolute maximum for weight on these motors..

You could solder the motor directly to the esc's, that should save about 15g. If you shorten unecessarly long cables you will be suprised by how much weight you can save!!
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Old Aug 11, 2014, 08:11 AM
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United States, MD, Annapolis
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It will fly but sluggish with the 1804s in my opinion.
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Old Aug 11, 2014, 08:59 AM
Team WarpSquad
United States, PA, Doylestown
Joined Jan 2014
3,469 Posts
Quote:
Originally Posted by Waterbound View Post
It will fly but sluggish with the 1804s in my opinion.
Correct, If it flies at all.
The RCX1804-2400kv motors are pretty good but only for a MAXIMUM AUW of about 450grams.

The scale in the photo shows 519grams and four motors will add another 100grams for an AUW of about 620gram.
The RCX1804's are just too small. You will need at least 1806's or 2204's and preferably 1808's or 2206's.
Can that frame run 6 inch props? or only 5 inch?
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Old Aug 11, 2014, 11:42 AM
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I connected all the motors and it seems to work, but there is a problem.
while flying usually the motor 3 crashes and makes me drop everything. I noticed that warms slightly more than the other. now does not seem to do it again, but I'm not sure.
after several adjustments no longer does.
I let my values ​​kk2.15 stock 1.6 firmware.

roll (ailieron)
gain p 45
limit p 20
i gain 30
the limit 30

pitch (elevator)
same as above

yaw (rudder)
gain p 60
limit p 30
i gain 45
the limit 30

sel level
gain p 35
limit p 25

Now since I soldered the motor to the escs, would not that be a problem welding?. or the motor is defective?
or is it just a matter of adjusting ??
help me please.
(sorry for my bad english)
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Old Aug 11, 2014, 12:53 PM
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Its either underpowered and struggling (need more thrust), the draw on the ESCs is greater than the max (need bigger ESCs), bad soldering job (cold solder joint).
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Old Aug 11, 2014, 01:19 PM
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Italy, Lombardy, Como
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162 Posts
I tried to do a bit of flying at very low altitude. the quadricopter flies very well, he gets up at half throttle. I do not know what to do, the only problem is the motor number three, which also heats up even more.
Now I do not know whether to buy another engine, redo the welds.

in this video you can see the problem, suddenly flips. always the fault of that engine?

zmr 1804 2400 kw (0 min 40 sec)
(0:24)
I still dropped the weight. now it is about 550 grams with 2200 mha, I will take a smaller battery to fit under the 500 gr, but first I have to solve this problem.
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Old Aug 11, 2014, 02:27 PM
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those motors are crap, I don't trust them anymore, I had several go out on me in flight. You need to scrap them and get some proper motors..
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Old Aug 11, 2014, 02:29 PM
Team WarpSquad
United States, PA, Doylestown
Joined Jan 2014
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Take the camera off the quad and mount it on a stand. Then record what the quad is doing. I can not tell anything with a view from the quad.

Do re-check all the solder joint between the battery and motor.
Do reduce the AUW.
Which ESCs are you using? What firmware do they have?
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Old Aug 11, 2014, 02:29 PM
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I disassembled the motor number 3 and I discovered that there was a bad weld. I rebuilt and now it seems to work, but I can not trust to do FPV.
zmr 1804 kk2 (1 min 22 sec)
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Old Aug 11, 2014, 02:31 PM
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I still bought another motor, if the exchange rate. thanks to everyone for the tips!
i am using 12 amp afro escs
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Old Aug 11, 2014, 02:57 PM
Team WarpSquad
United States, PA, Doylestown
Joined Jan 2014
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The quad is now flying nicely and this is easy to see from the new video.
Go out to a large field and fly it LOS for a while to get used to how it flies and get confidence that it will not fail and crash.
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Old Aug 11, 2014, 03:03 PM
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Quote:
Originally Posted by waltr View Post
The quad is now flying nicely and this is easy to see from the new video.
Go out to a large field and fly it LOS for a while to get used to how it flies and get confidence that it will not fail and crash.
thank you very much for the help !!
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