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Sep 25, 2016, 08:52 AM
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QX90 and others with F3 brush, benefit of 2S transformation possible?


A lot of people are asking if a upgrade to 2S is sufficient on a QX90 and others with the same FC. Same with me, so i modified my thrust test stand to be able to measure coreless 820 motors.

All measurements were done with constant current up to 3.7 V resp. 7.4 V. The following calculations are based on:
1S spare Motor QX90
http://www.banggood.com/Eachine-Tiny-QX90-Micro-FPV-Racing-Quadcopter-Spare-Parts-8_5x20mm-Coreless-Motor-p-1079157.html
2S Motor X600
http://www.banggood.com/MJX-X600-RC-Hexacopter-Spare-Parts-CW-CCW-Motor-Assembly-p-991790.html
JJRC 1000A Propeller
http://www.banggood.com/JJRC-1000A-RC-Quadcopter-Part-Propellers-1000A06-p-928073.html

I also did measurements with stock propeller, but due to their unbalance and resonance effects i did not use these.

Having a look on the following diagram we see the 2S System has about 8% more thrust at the same electrical power. Maximum thrust is almost 20% more.



But what about overall performance?
The following table is summarizing the results. The flighttime is just an assumption based on hovering power and no addtional power draw...


So adding a second 600mAh battery adds 15g to flight weight, so each motor has to have 17.6g thrust for hovering. This configuration adds some flighttime but only 20% additional thrust.
It might result in flying a bus with extended range.

I also calculated two additional battery configs, 2S 150mAh and 2S 350mAh.
The 150mAh has almost the same weight with 20% more thrust, so it might turn into a aggressive shorttime racer.
With 350mAh you add some weight at the same flighttime with 20% thrust gain.

Keep in mind the camera is only capable of 1S and has to be resoldered from the battery connector to a 5V output.
Last edited by Mephi; Sep 25, 2016 at 03:11 PM.
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Oct 08, 2016, 01:56 AM
Here and there...
Thread OP
reserved for additional measurements...
Oct 14, 2016, 07:16 PM
MODDED MICRO MULTIS FPV
MONOAMORE's Avatar
Awesome work Mephi! I'm trying to pair a 2s lipo with my 55g hex.
Oct 14, 2016, 08:21 PM
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MONOAMORE's Avatar
What about current? How many amps does the 2S system draw at hover?
Oct 14, 2016, 08:32 PM
We are not men, we are DEVO 7e
xanuser's Avatar
Quote:
Originally Posted by MONOAMORE
What about current? How many amps does the 2S system draw at hover?
doesn't sound like that's data is possible with OP's testing procedure.
Quote:
Originally Posted by Mephi
...so i modified my thrust test stand to be able to measure coreless 820 motors.

All measurements were done with constant current up to 3.7 V resp. 7.4 V.
Latest blog entry: MY notes/ Ascent 2"build notes
Apr 03, 2018, 03:41 AM
Registered User
Good work! Any considerations regarding possible benefits of higher voltage available to power up the receiver?


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