Small indoors FPV Quad Project

by Hasi | February 26, 2015 | (7) Posted in Projects

I wrote a blog on RCGroups about my micro sized FPV Quad project, which became very popular, so I thought I'll post it on flitetest. I wanted to have a small FPV Quadcopter, so I can also fly indoors. My goals were small size, some crash resistance, reasonable flight times and performance, good video quality, good flight characteristics, reasonable range, and I wanted to use my existing transmitter which is a Taranis with a FlySky (same protocol as the Turnigy 9X) module in the back.


Small size & crash resistance: There are some frames out there, but I chose one of the 100 sized platform frames from picnicquads.com. It is made out of a sandwich composite material, so it is tough, yet very lightweight. You can also choose from different motor sizes, because the motor mounts are separate.



Flight times & performance: To accomplish these I did some research on RCGroups about the best motor/prop combo. Next I calculated the MTOM to be about 50g with a bigger (750mAh 1S LiPo) battery, which meant I need to have 100g+ thrust. RCG member woodsturning did a lot of micro quad equipment testing and for my needs the Chaoli CL-0720 motors with the Hubsan propellers seemed to be the best.

Video quality: After watching some DVR videos of small cameras I decided to use a 520TVL MC900 with a wide angle lens from FPVHobby. It has a really nice image and also works in low light conditions. I have a Fatshark Base with a built in receiver, which is fixed on 5705Mhz, so the VTX also had to have this frequency. The TX5810-100 also from FPVHobby has this Frequency, so I bought it despite the unreasonably high price. It also turned out, that the channel memory doesn't really work. It only works if I disconnect the battery for a few seconds. Otherwise I always have to cycle through all 8 channels to see a picture in my goggles. I also had to use a Pololu 5V step up voltage regulator to get rid of the noise from the motors.


Flight characteristics & range: This was the complicated part. Because of the size and weight limitations a separate RX and FC was out of the question. Since there is no available Frsky or FlySky micro FC on the market I had to build my own. RCG member midelic already had an ongoing project to build a Multiwii board with integrated brushed controllers and FlySky RX. He wouldn't build me one, so I built my own. Since 1 piece would have cost me a fortune I ordered parts for 18 pieces and decided to sell the rest later. I built my own and did some testing. There were some bugs in the code first, but midelic fixed them for me and now it works flawlessly.



Conclusion: All together the quad cost me $175. Despite the problematic and expensive VideoTX it all came out working very nicely. Range is very good. Indoors I flew about 50m with several walls between me and the quad while maintaining good control and adequate image quality. Currently I am using 500mAh 1S LiPos, because I already had them. I get flight times of about 8 minutes, so there is really no need for the bigger battery. T/O weight including the battery is 45g, which is lower, than calculated. The performance is very nice and the control is very precise. I can fly through holes that are twice as bis as the quad.

Ad: If you ever have the same problem like me with the small FC, contact me and I will sell you one of the boards. I build and test each one myself. The dimensions are 43x25mm (including PCB antenna) and it weighs only 2.7g. I sell them for $30 including worldwide shipping. I of course have midelic's permission.

COMMENTS

Rust15 on March 3, 2015
Cool article and nice micro quad!! Would your board be compatible with a Spektrum compatible transmitter? Sorry if that's a dumb question, but I'm not very familiar with the different radio brand compatibilities.
Log In to reply
Hasi on March 4, 2015
No. It's only compatible with the FlySky system (radios like FlySky/iMax/Turnigy 9x/Eurgle 9CH, Turnigy i10, HobbyKing T6A).
However there is a board similar to this, but for Spektrum on HobbyKing: http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=42255&aff=395981
Log In to reply
spastickitten on March 5, 2015
I would love to see more and might buy a board can you give me a parts list?
Log In to reply
Hasi on March 6, 2015
There are links to the parts I used in the article if you look closer.
Log In to reply
FTprime on March 6, 2015
I would love to see a video

Log In to reply
spastickitten on March 6, 2015
So I am thinking of making a mini tricopter so any ideas or help?
Log In to reply
Hasi on March 7, 2015
Not this small, but I already have built a small tricopter: http://www.rcgroups.com/forums/showpost.php?p=29600988&postcount=6948
Log In to reply
spastickitten on March 7, 2015
I have seen some stuff that will be perfect like lemon rx's ppm receiver and the naze mini and the cc3d racing edition and the flip32 racing edition and these https://www.sparkfun.com/products/9457
Log In to reply
spastickitten on March 6, 2015
I also would like to see where you got the esc components to make my own. I can't find any escs for the small motors and i would love to see how you did it!
Log In to reply
Hasi on March 7, 2015
The ESCs are integrated into the board.
Log In to reply
spastickitten on March 7, 2015
also if you make a board with an output for the servo part I might get it!
Log In to reply
Hasi on March 12, 2015
I think we can arrange that. PM me on RCGroups, or on the flitetest forum.
http://www.rcgroups.com/forums/showthread.php?t=2367903
Log In to reply
IronKane on March 12, 2015
I'd like to buy one of those boards. How do I get one?
Log In to reply
Hasi on March 12, 2015
Contact me on RCGroups: http://www.rcgroups.com/forums/showthread.php?t=2367903
Or on the flitetest forum.
Log In to reply
fastfred529 on May 1, 2015
I want one.
Log In to reply

You need to log-in to comment on articles.


Small indoors FPV Quad Project