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Jan 18, 2014, 04:18 PM
Registered User
Fred.'s Avatar
Thanks Obelix for that interesting information.

HS6MTU posted a new video with interesting data.
Battery is now 2200mah and flight time 22mn.

LittleDuck 2200mAh battery flight (33 min 55 sec)
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Jan 18, 2014, 04:56 PM
Registered User
EndOfDays's Avatar
@obelix662000
I try to stay out of the topic, but as you did some math, math is only helpful
when done correctly.

Mistake 1 AUW of the "extraterrestrial" quad is 1,1kg

Mistake 2 energy density of the batteries used are very different. About
260Wh/kg in my case and 180Wh/kg for the "extraterrestrial" quad.

Mistake 3 There is no 15" prop on the market that would give 70-75% efficiency
(to reach 63% overall system efficiency) the most we get out with props
available (and seen in the video) is about 35-45% (which leads to 30-40% overall
efficiency). If you redo your calculation with the above corrections the prop efficiency would need to be close to or above 100%.

best regards
Ferdinand
Jan 18, 2014, 05:04 PM
Registered User
Quote:
Originally Posted by EndOfDays
@obelix662000
I try to stay out of the topic, but as you did some math, math is only helpful
when done correctly.

Mistake 1 AUW of the "extraterrestrial" quad is 1,1kg

Mistake 2 energy density of the batteries used are very different. About
260Wh/kg in my case and 180Wh/kg for the "extraterrestrial" quad.

Mistake 3 There is no 15" prop on the market that would give 70-75% efficiency
(to reach 63% overall system efficiency) the most we get out with props
available (and seen in the video) is about 35-45% (which leads to 30-40% overall
efficiency). If you redo your calculation with the above corrections the prop efficiency would need to be close to or above 100%.

best regards
Ferdinand
LOL

You forgot that with the Net Maths and the YouTube Maths ... everything is possible

Including some magic from pulse ESC

Jan 18, 2014, 05:06 PM
Registered User
Quote:
Originally Posted by Fred.
Thanks Obelix for that interesting information.

HS6MTU posted a new video with interesting data.
Battery is now 2200mah and flight time 22mn.

http://www.youtube.com/watch?v=CfSy0wWmc-U

He made the "2 hr" flight video private so it is no longer viewable. Shows a lot of confidence in his work.
Jan 18, 2014, 05:15 PM
Registered User
Quote:
Originally Posted by milo12
He made the "2 hr" flight video private so it is no longer viewable. Shows a lot of confidence in his work.
If does 22min with 2200mAh, no way he can do 120min with 9000mAh

Anyhow, I feel is a waste of time to discuss about it .. there is nothing to learn from, if not how to badly cheat ...
Jan 18, 2014, 05:24 PM
Registered User
Quote:
Originally Posted by e_lm_70
If does 22min with 2200mAh, no way he can do 120min with 9000mAh

Anyhow, I feel is a waste of time to discuss about it .. there is nothing to learn from, if not how to badly cheat ...
Read description. His quad use 1905 mAh at 22 min . I think him change parameter and I like obelix662000 analyzed
Last edited by dragonui; Jan 18, 2014 at 05:32 PM.
Jan 18, 2014, 05:40 PM
Registered User
EndOfDays's Avatar
I am sorry guys, I cannot support the world being told to be a disk, since we know that it is not. Also this looks like that I am a bad looser, which is not the case I do really respect everyone performing work on this topic, but if 50-60% of the energy needed for a copter to fly do not come from the system battery but from somewhere else you can discuss this in every detail, but not here.

Was nice to discuss with you, looking forward to meet you all again in some other thread.

best regards
Ferdinand


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