A tiny FPV quad review : QX90 with modded electronics for FrSky compatibility


Here a shared review of a quite cute and tiny FPV quad, the QX90.

It was unfortunately delivered to me with a built in DSM type receiver so I could not use it with my Taranis radio.

I therefore modded the electronics with another tiny board that is incredible : it integrates a F3 flight controller with all bells and whistles plus an integrated FrSky compatible receiver !

I still have some stability issues with the receiver and Taranis. I am troubleshooting with the maker of this board and will post a follow up later on.

Views: 982

Comment by Tony Kenward on January 1, 2017 at 8:05am

Hola H,

Yes, I have a QX95 that I built up from the components you mention.  I started with the raw frame, then added hotter motors and an improved FPV camera/VTX unit.  I have a steep learning curve with brushed motors and Cleanflight, but I am getting in some quality flight time indoors with this little 'Whoop' machine.

I am intrigued about your 2S setup.  Did you order that directly?  I know the F3 board has a solder jumper to select 1S or 2S, but the QX90 and QX95 typically ship as a 1S-powered quad.  They ship with a 1S 600 mAh battery.

Have you flown a 1S for comparison?, I am curious to know if twice the voltage is worth the weight.

Comment by Tony Kenward on January 1, 2017 at 8:06am

Addendum:  link for the 1S QX90 here:     http://www.banggood.com/Tiny-QX90-90mm-Micro-FPV-Racing-Quadcopter-...

Comment by Hugues on January 2, 2017 at 1:45am

yes it came with a 2S battery. And yes you have to solder the 2S jumper on the F3 board

2S surprised me too but it flies great even with the extra weight.

Comment by Tony Kenward on January 2, 2017 at 9:05am

I recommend using high quality batteries like these from Turnigy:  https://hobbyking.com/en_us/graphene-750mah-1s-w-2pin-molex-connect...

Also, I like the separate receiver unit for FrSky.  I went with the long-antenna version here:  http://us.banggood.com/Wholesale-Warehouse-Tiny-Frsky-8CH-Receiver-...

There are a lot of parts now available from Bangood's US warehouse now.  There are a ton of hotter motors for these little machines on the 'net too.  One disadvantage of the DIY F3 board is that the motors must be soldered to the board;  no connectors like the BNF package.  That makes replacing motors a bit more tedious.  And, YOU WILL BE REPLACING MOTORS.

Comment by Hugues on January 2, 2017 at 12:58pm

thx for the battery reference. What brushed motors are best in your experience ?

Comment by Tony Kenward on January 3, 2017 at 8:42pm

Well, it all depends on how fast you fly and how often you're willing to replace motors.  These little brushless wonders are only good for 1 to 2 hours total.  If you push a 35C battery with a hotter motor, you're sure to puff them out.

The 'standard' motors are rated at 39k RPM.  If you are not pushing hard the 'Chaoli' 8520s have a good reputation.  http://www.banggood.com/4X-Chaoli-CL-820-8_5x20mm-Coreless-Motor-fo...

I run the 53500 RPM 'RacerStar' motors currently:   http://www.banggood.com/4X-Racerstar-8520-8_5x20mm-53500RPM-Coreles...

If you are 'insane', then you want to consider a 73 thousand RPM motor set like these from Micro Motor Warehouse: http://micro-motor-warehouse.com/collections/all-motors/products/cl...

I have no experience with running these with 2S voltage though.  I would be interested to hear what kind of life you're getting out of them with twice the voltage.


You need to be a member of DIY Drones to add comments!

Join DIY Drones

© 2020   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service