This is a blog that on how I do my Multi-rotor builds, use this info at your own risk and if you buy the stuff that I document, then it is at your risk. I like to explorer buying things that sometimes don´t work as desired or need tweeking If you are looking for stability buy branded products, they are tested and tried. If you go cheap, then expect to be dissappointed at times and buying unbranded products require extensive testing before being put to use
Some time ago, my usb connector on my Multiwii Pro got accidently ripped, when i tugged on the cable, this is a common issue with many boards with the usb connector. I purchased a new FC and parked the Multiwii together with everything else that was buggered.
Just a few days ago I stumbled on an article on how to connect the board to my PC using a FTDI basic adapter. I have on of these adapters as they are very useful when working with quad building. They are relatively cheap and can be purchased her on Ebay.
Grab your FTDI basic
Connect the cables
Find J2/serial port
GND on the basic goes to GND on the FC
VCC on Basic goes to +5v on the FC
TXD on the basic goes to RXD on the FC
RXD on the basic goes to TXD on the FC
DTR on the Basic goes to DTR on the FC
Connect the usb cable from the PC to the USB port on the basic, Remember to download the drivers for the FTDI controller from her and install them.
Your flight controller should fire up,
Choose the correct com port and you can again update your firmware using the FTDI basic
Now you can start mission planner, choose the correct COM port and press connect, you are now able to use your board like you did before
As i mentioned earlier, my first experience with building quads was short lived, I got carried away with the endless possibilities of the more advanced flight controllers like the Crius AIOP, with its many features, like bluetooth connectivity, gps and waypoint navigation, telemetry, OSD. So i went ahead and purchased a Cruis AIOP with the above mentioned equipment. This was very short lived, the first board I had purchased I smoked because of a misunderstanding in the manual. I toasted the board by applying 5 volts to the wrong section of the board. I purchased a replacement board from RCtimer and while waiting for it to arrive I actually managed to solder the missing copper strand on the circuit of the board using a 28 gauge wire.(Thats why i never throw out, what i assume is busted). I had previously upgraded the firmware to version 2.9r1. I tested the board and it worked fine, so I was actually now left with two working Crius boards. It took me a while to wire my quad as I didn't want to repeat my mistake.
After setting up the board, flying and setting up the board was a hassle, the quad was unstable, flipped at times, had a whole lot of oscillation and was generally very unstable. I tried adjusting the PID and this only added to my growing frustrations. I searched the internet for help on PID tuning but after a few months i decided to give up on my Crius board and purchased the KK2 board. After installing the KK2 board i practically loved it. It was no nonsense, simple and after upgrading the firmware to version 1.6, I flew from dag 1 using the autolevel feature. The board is cheap, easy to adjust using the on screen display and as it does not present the same upgrades/features like the Crius I had to settle with just learning to fly, which in part was an excellent thing. I flew with the KK2 a couple of months and gradually learnt the basics of flying. The last couple of months have been almost crash free.
Just the other day i found my Crius board again and mounted it on my Talon together with the GPS, bluetooth, telemetry and OSD. I had to spend hours upon end wiring it together, the GPS and the telemetry share the same serial port and to be sure that i got everything right si I took my time.
My initial test didn' t work well as one of the ESC was not working so I had to wait 14 days for a cheap ebay replacement from China. When i finally mounted the new ESC, I adjusted the PID values to a value I saw on RCjoses Youtube channel just to see if that could get me started in stabilize mode. If I could get it to fly, then i could use the autotune feature of the Arducopter 3.1.5 R2 firmware.
I eventually tested the PID values manually and came up with the following on my setup
I was surprised to see that the quad took off and was rock solid. It did drift quite a bit, but that I found was quite easy to fix by using the Autotrim feature of the Crius board (well i think it is). This feature is present on the Arducopter and is mentioned on different forums, so i did the same procedure on the Crius and it worked pretty well. When arming the Crius you can use the same feature as described in the video below.
When arming the board (left stick - bottom right) and the board initiates and begins the arming process, i kept the stick in the arming position. The board finished arming the red LED becomes constant/solid, meaning that the board is armed. After 5 or so seconds with the arming stick still in the arming position, the board initiates again and this time into the autotrim sequence, the LED's begin a blinking sequence yellow and red. I took off and held the quad in stabil hoover for about 25 seconds, the autotrim will stop automatically and the board writes these new trim values to the board. This to my amazement gave me a well trimmed and very stabil quad. I have now tested some of the features like loiter, altitude hold and this board rocks. But like i previously stated, if you new to quad building go with the easy choice first, the KK2 will get you up and running in no time. It will give you immediate success, but will limit your possibilities in regards to waypoint navigation, osd, telemetry and so on. Once you have learnt the basics, then the Crius board will offer you the ekstra fun. This board is far superior and its features are fun to explorer and use. It requires a lot of patience in the building process, the wiring can be a bit confusing, but hopefully if you start simple, then with the basic knowledge you gain, wiring the Crius is more simplified.
One of my Turnigy Multistar 20a ESC´s started playing up, I wanted to purchase a new Afro ESC with the simonK software pre flashed, but Hobbyking had the item on backorder and it often takes time to restock. I decided to try a cheaper Ebay esc to see if they were any good. So I purchased a 30 amp ESC for $8.40 with SimonK preflashed. Rather than wasting a bunch of money buying four and then finding out that they are useless. I ordered a single ESC to see how well they cope, if they are ok, i may purchase a few more.
The 30 amp ESC came packed in a sealed antistatic bag
There are no bullet connectors mounted, so some soldering will be required, the wires are pretty flexible and the shrinking/finish is quite neat.
I had to solder three female banana connectors on for the motor side and heat shrink the connections
Two male connectors for the power side.
Connect the motors
Plug in the power to the power distribution board and the signal cable. I am currently running 20amp ESC' s on the quad, mixing different amperage ESC's should not be a problem as long as they can handle your battery and motor setup.
Inital test seems ok, will have to see how it copes in flight and how the ESC holds up.
Well took a test flight with the cheap ebay esc and well it works pretty ok, I am not an expert on such matters and I hear talk on the different forums that these cheap ESC's are in actual only cable of pulling a max of 20 amps even though they are sold as 30 amps, I am not at all able to test this as my electrical knowledge does not go that far, all I can tell you is that they work fine on my setup running 4000 3s batteries, my other esc' s on this quad are turnigy multistar 20 amp and even with this mix in esc the whole setup is balanced. Buy at your own risk, how i do things is how i learn, buy original branded products and pay that bit more extra if you want something that works out of the box. If you are like me and like to play around testing different things, then well here is an option.
Verdict Been running on these ESC for a couple of months and so far flawless using 3s batteries, have now mounted on booms and the ESC's function without even getting warm. If you are looking for a cheap Ebay ESC alternative, then this you can count on. But be aware, these cheaper Ebay alternatives are not tested before they are packed and shipped, so you might receive one that does not function properly, the Ebay seller i use just usually sends me a new one without complaining or having me send the useless one back and shipping is relatively fast so within a week i get the replacements. So thats why you pay the extra dollars for the Hobbyking ESC's, I received 8 working esc's before i received two bad of the replacement that i arrived one was bad and now expecting that to rearrive shortly. But as i mentioned in a working state, these function flawlessly. Update - oktober 15: Well after many months of flying, these ESC are still solid, though i must mention the last shipments i received were faulty, for every 4 i bought, at least two malfunctioned, took a while to get replacements from the seller and i guess he must be pretty tired of me, claiming that they don´t work.
What not to buy
I also purchased a single version of this cheaper ESC, this is one of the most common ESC' s on Ebay, so i thought i would give it a go. Priced at $7.60 it is just under the price of above 30 amp ESC
The specifications for the given ESC are :
So roughly the same specs. This ESC was a massive disappointment. The first that arrived was mounted, throttle range was configured and I flew a full battery, with no issues. The next battery was mounted, the motor spun once and the ESC died. I was sent a new replacement ESC and practically the same issue. The ESC flew one full battery and on the second battery, the motor started choking and white smoke appeared from the ESC. The ESC smells burnt, so I would definitely not recommend this ESC, The red ESC' s mentioned above are still stabil and have now run 10-12 batteries without any issues whatsoever.
