Eachine Tiny QX80 customization … by David HK September 2016

Eachine Tiny QX80 customization … by David HK September 2016

I am new to the quad hobby for less than 1 year, within this short journey, been with

•          MJX X101, bought this was thinking to put a gopro cam, but my friend told me no one will put a US$400 gopro onto a US$80 quad, luckily i didn't, as it flied away within 2 months,
•          JJ1000, bought 2, ported 1 of the FC onto a 110mm X frame, flied great in the field, but after a few weeks, it eats each battery within 1 minute, IDKY.  The other one in original frame, now only fly it inside the house when I am bored, but it is still a great little quad
•          Emax NH280 Pro, lost 1 in the field within 3 months, luckily bought the 2^nd one during Gearbest flash sales in Jan 2016 for around US$100, this is still going strong and is my primary play toy,
•          Syma x5s, bought it when I lost my 1^st NH280 and feeling down, was thinking lets learn it from the basic, but couldn’t get any excitement out of it.  Only play it for 2 weeks then sold to a friend.

So now, a month ago I saw the Eachine Tiny QX90 and QX80, read and watched every piece of material about them in the web.  I decided and bought the QX80, because:

•          Having previous experience of the JJ1000 FC board on a raw X frame just like the QX90, I know the motors will be easily shifted (ie not 100% vertical) after crashes, and if using the motors as the frame legs, hitting the ground first, it may cut the motor wires at the bottom and sometimes may even open up the motor bottom cover.  Although JJ1000 uses 720 motors while the Tiny quads use 850, but I think the design is basically the same.  The QX80’s motor housing will hopefully prevent the above concerns.
•          The QX90 fpv view is obstructed by the motor and some props right in the middle, while QX80 only see a small bit of props at the top fpv screen.
•         The QX80 frame seems to be much more robust and tough, but the down size it is a few more gram heavier.

I bought my QX80 from China Taobao site (I can read Chinese and I live in HK), because Banggood refuses to ship anything with battery in it even though gearbest and hobbyking are shipping it all the time, also a month ago, for international sites, only Banggood sells these tiny quads. So if you want to buy your QX80 or QX90, you can get it from Banggood in below URL:
http://www.banggood.com/Eachine-Tiny-QX80-80mm-Micro-FPV-Racing-Quadcopter-PNP-Based-On-F3-EVO-Brushed-Flight-Controller-p-1073903.html?p=3629013638443201601A

http://www.banggood.com/Tiny-QX90-90mm-Micro-FPV-Racing-Quadcopter-BNF-Based-On-F3-Flight-Controller-FrSKY-Taranis-X9D-p-1069614.html?p=3629013638443201601A

However, in Taobao shops, the QX80 (or QX90) only carries either the DSM2 receiver or no receiver, but my radio is 9XR Pro with a DJT module, so I bought one without receiver.  They have the option of assembled (for extra US$5) or kit version, so I bought the assembled version because the shop already warned it is difficult to assembled because the frame is very tight, needs sanding + lubricant to assembled the frame.

For the receiver, I originally ordered the same tiny frsky compatible rx used in Banggood’s BNF version, but it was in back order for 2-3 weeks.  In the end, I bought the KS-Servo AC810, also from Taobao in another shop but within the same consolidated shipment.  I felt lucky I bought the AC810 (you can get AC810 from hobbyking and F801 from banggood, they are basically identical), as it turned out, I can flashed an open source firmware and able to get RSSI and voltage telemetry from it (see my other blog for details).

Now back to the original subject, the customizations (or fixes) I did to my QX80 are:

1.       Leveled the legs

The assembled frame as received did not quite level upin 3 of the motor housing legs, as you can see, there is still 1 to 2 mm gap, making 3 legs not leveling up when put it on a table.

To fix it, I took out the motors and the plastic rings, applied some WD40 to the joints, then used a bent nose pliers, hold the frame in one hand, and the pliers in another, really used some force on the pliers, don't be afraid, the frame will not break!

You will hear a clear and loud ‘click’ sound, and then the joint parts will be in perfect alignment and level.

2.       Moved the F3 EVO board right in the middle of the frame, I don’t know whether this will make any difference, I just want to make sure the board is placed symmetrically as in a brushless quad.

3.       Applied some hot glue to the vtx antenna joints, to absorb some impacts.

4.       Added a buzzer, and a buzzer switch in cleanflight / betaflight.  This proved to be very useful when flying outside, found the quad much easier after a drop.

but it continuously beeping even when inserted a fresh battery and armed.  I think it is something to do with the voltage detection somewhere is not right.  So now I temporary disable the VBAT feature in cleanflight and use it as a lost quad buzzer switch.  I planned to flash to betaflight soon, which I saw in youtube that one can stop this continuous beep sound in CLI using the beeper command (betaflight only)

5.       Built an anti-roll T-bar using 2 zip ties and a heatshrink, and also hidden the rx antenna inside one of vertical sections.

Need careful placement of the zip ties and just manage to avoid the props!

6. Added a prop guard by cutting an old one, used it for a few times, but the QX80 feel heavy at 51g before battery! So now need to rethink on how to reduce weight.

7. Flashed to betaflight 3.0 - basically follow the instruction from the the betaflight install link below:
https://github.com/betaflight/betaflight/wiki/Installing-Betaflight

1. download Zadig then open Zadig
2. short the boot pins while connect the usb cable to your PC, once connected, can leave off the boot pins as the board is now in bootloader mode, ie no LED flashing.  if flashing, try again until you get no flashing
3. in Zadig screen, click Options -> List all devices
4. select STM32 BOOTLOADER in the pull down list
5. select WinUSB (v6.1.7600.16385) as the driver to install, click Reinstall Driver.  Done!
6. run Betaflight configurator, disconnect the usb cable, select SPRACING F3 EVO, version 3.0, Full Chip Erase, No Reboot Sequence.  load firmware online.
7. now also need to short the boot pins while connecting the usb cable
8. in Betaflight, click flash firmware, then you are done!