Quad Build Blog
DJI Phantom 3 Snapshot
Snapshot: Beautifully made. Like Apple products in design and packaging. White. Clean. Simple. Transmitter is
How can you monitor all these things while flying? Easy, because in P (position hold) mode the craft
My Quad Build Blog
by Earle Levine
05/11/14 FAA Head Shows Understanding of Model Aircraft Status
With what feels like an unending strream of bad publicity and calls for regulation of "drones", FAA Administrator Micheal Huerta has show a good understanding of the difference between hobby model aircraft and the "drone" regulation talk. Click HERE for his recent statements.
I have been tinkering with multicopters (four motor ones called quadcopters or quads) for about a year now. While I never caught the helicopter bug, these odd combinations of flying machines and computers got my interest. Until very recently there were really no ready to fly quads. They were in the realm of the hobbyist and tinkerer. There was a lot to learn, but if you are not learning, things get boring. So off I went. First I will give the listing if my current machine, which is very stable and reliable.
05/08/14 NEWS: Hobby People is advertising a 480mm size quad semi-kit RXR similar to the discussion below. The frame looks like a DJI Flamewheel clone. It is advertised at $199.95, significantly higher than the X525 kits listed below, but if you want to buy locally, it is an option. And they claim to have spare parts - it is nice to have a local source of props. I don't know what control board they have. It does not have GPS but may have GPS capability as most boards do these days. The biggest deal breaker I see is the requirement / suggestion to by a "4 ESC battery power adapter" for $24.95. In the quad kits listed below this is a small INCLUCED PC board that makes all the required connections (soldering required). Bought separately these cost about $6 - 8 (search for power distribution board" on eBay. These can certainly be made to work, and the soldered connections will eliminate the voltage loss at the connecters of the HP board.
Perhaps a better option is the HeliPal Flamewheel F450 combo. You get DJI Naza M Lite controller, DJI motors and props and a DJI Flamewheel frame for $309. In my opinion better components all around.
Click picture for HP website info.
Interesting series comparing DJI Flamewheel F450 with clone
Here is a link to another persons build log on the X525. It is very good and I recommend it! (The KK flight control board described is pretty basic and requires tinkeriing, read my article below for more information on flight control boards)
CURRENT QUAD BUILD:
My current quad is a 525mm (20") size with aluminum arms and a multi-deck fiberglass center section. It is very stable, simple, rugged and good size and confidence inspiring. A good choice for (legal) aerial photography and learning. Here is a link to get everything you need in one package ($129.95 free shipping)
The flight controller with this kit is a MultiWii SE 2.5, which has gyroscopes, accelerometers, magnetometer (compass), and barometer. This allows good flight stabilization, orientation control, and some altitude control. A GPS can be added for even more capability, User should be comfortable using the computer interface to make necessary adjustments. Buy a number of extra Gemfan 8x4.5 sets of propellers and some extra motor mounts, the most common crash damage. See below for link.
I am currently using the NAZA M LITE flight control ($169 with GPS at Goodluckbuy.com). This is highly stable and allows good "hover in position" ability, and a good degree of maneuverability but no wild aerobatic tricks. The cool looking dish on top is the GPS and compass module. All needed items can be ordered from goodluckbuy.com in China, with FREE SHIPPING and relatively fast delivery. Plus if you browse around their site you will find LOTS of other cool stuff - they have everything! I have had very good luck (pun intended) dealing with them.
PROPS: Order at least 3 sets of each of each color.
I recommend ordering 60 LED per meter LED tape in white and another color for orientation. These run fine off the 3S 2200mAh (or higher) Lipo. HobbyKing is cheaper but I order the 4 color strips from Goodluckbuy so they would all arrive together, The strips are long enough that you can cut on in half to have the same color on two arms.
Another handy gadget for all lipo users it the very loud low voltage alarm for 1-8S lipos, with digital readout. Get several. $6.07
Your choice of 6ch+ radio and 3S 2200 mAh or higher battery. Don't use 4S to start - you have enough power and it will complicate hooking up the LEDs.
Your choice of plastic bowl or container inverted to use as a "fuselage" on top.
If you order the above kit, the NAZA M LITE flight controller with GPS, and the 8x4.5 props listed above, you will have essentially the same set-up I have. The only difference is that I used the 4 in 1 Q Brain ESC instead of the four separte ESCs. It has worked well but the frame needed to be customized by adding another layer to accomodate the unit.
ESCs: The ESCs that come with the above sets are fine. I am currently using the Q Brain 4 in one ESC, which mounts in the center of the quad. This makes a neater installation, but I had to add another "deck" to make a place for it.
Q Brain 4 x 20A Brushless Quadcopter ESC 2-4S 3A SBEC
Also good are the Hobby King Afro series that are designed for multicopters. They are "flashed" with "Simon K" software that is more responsive for the quick changes that multirotors require.
Afro Slim 20Amp Multi-rotor Motor Speed Controller (SimonK Firmware)
PROPS: I would order a good supply of Gemfan 8x4.5 props (orange and green for orientation, clockwise and counter clockwise). They will break and you don't want to be grounded for lack of a $1 prop. Order from Goodluckbuy.com if you are ordering the X525 combo. If not you can order from Hobby King USA.
Hobby King USA
FLIGHT CONTROL: NAZA M LITE flight control system. This is a commercial grade software at a hobby price. You can order this with or without GPS. GPS ads accurate Position Hold, Return-To-Home and Intelligent Orientation Control functionalities. GPS is worth the money.
LEDs: LED strips for the bottom of the arms, necessary for orientation, in my opinion.
Orvac Electronics, 1200 S Shamrock, Monrovia CA
Turnigy High Density R/C LED Flexible Strip-Red (1mtr)
Aluminum Square Tube DIY Multi-Rotor 12.8x12.8x250mm X525 (.5Inch) (Red)
RADIO: The more channels the better up to 7. End point adjustment and a 3-position channel switch is helpful. A 2.4 radio with a small receiver is best.
BATTERY: 3s lipo, 2200maH or higher. 20C seems sufficient.
READ: Visit RCGroups multicopter forums and read everything you can.
My History with Quads
Searching eBay and the internet, he coolest looking quad at the time was the IFly-4 by Ideafly. These are still available with more modern controls, from Hobby King.For $219 still not a bad deal. I bought one on eBay with some extra parts and a "Rabbit" control board. I had to dig to see how the board worked. It had an intimidating
row of LEDS at the front, that flashed in mysterious patterns and colors, that seemed do convey some meaning. Remeber the lights on the space ship from Close Encounters? I was able to find some badly translated documentation. I learned early that best source of information for all things quad is RCGroups.com.
Flight Control Board Background
This is probably a good point to talk about flight control boards (referred to as FC). They are the heart and brain of the quad, and what makes multirotor flight possible. Most of us are at the point that we have some understanding of LiPo batteries, brushless motors and ESCs, volts, watts and amps. Those are the airframe of MCs. (See what I mean about learning new things - how many of us knew about these things five years ago?). Anyway the control boards (FC) are a fortuitous convergence of technologies.
The computing power of the FC is provided by various micro-computer chips. Imbedded computers are in everything from wristwatchs to stoves and our cars. Everywhere. Many are made by a company called Atemel and they make lots of different kinds.The thing they have in common is that 1) they are programmable, 2) they take electrical inputs and 3) process the inputs to create useful outputs. Some clever Italians installed one of these on a small circuit board with easily accessable inputs and outputs, and developed a computer interface that made it possible, and relatively, easy for hobbyists and artists to program. Usefulness is only limited by the imagination.
This system is called Arduino (Italian for something like "little worker"). Go to http://www.arduino.cc/ to learn more about that fascinating world.
Other hobbyists found various sensors to provide real world input. To fly a multicopter, certain movements must be sensed. What commercial technology could the hobbyists tap into. Wii game controllers! The "nunchuks" contained tiny accelerometers and gyros! And they were cheap! So, hobbyists took these out of the nunchuk and installed them on a board with outputs that could be linked to the Arduino. The Arduino now could sense movement.
Flight Control Programs
Now that the Arduino had the input sensors for movement, these inputs had to be processed into output that could fly an MR. Again the hobby and Open Source programming community to the rescue. Smart progrmmers with time on their hands adapted control theory programming to provide the necessary corrections to the motors. Movement sensed in an undesired direction or rate was counteracted by speeding up or slowing one or more of the motors. The theory used is commonly known as the P.I.D. system. Changes are sensed, and control reactions in the form of speeding or slowing motors are output, while compensating for over or under-reacting. The resulting Arduino program was named MultiWii based on the use of the Wii controller sensors. This is an open source program, meaning the no one owns it, anyone can modify it and distribute it (not for profit). Background, help and the latest version may be found at the MultiWii.com wiki. Other similar programs are BradWii, and APMP. Each have their own features and fans. Some commercial controllers such as DJI NAZA , Hoverfly, and APM use their own proprietary programming.
The Quest Continues