Monday, 14 September 2015

Multi Rotor Part 2 - Quadcopter Construction - Step 1

Scratch Building a Quad Copter.
How to approach - There are lots of ways you can build a Multi Copter.

Be wise, slow pace is better than running on both feet, you can easily get discouraged by trying to do things too fast.
  1. You can have a good experience if you start with a simple, small Quad Copter, with an All Inclusive Kit.
  2. For your first Multi Copter, DO NOT initially try to build a Photo / Video or First Person View copter, just build a good Quad Copter.
  3. Even if you know that’s what you really want to do, it will take you some time to tune up the copter and flight controllers.
  4. Don’t start the build from frame unless you have good confidence and skill in you.
  5. It is very important to NOT start out with a big (dangerous) multi copter with photo or video equipment on it, you will regret it.
  6. A small, agile Quad Copter is always a lot more fun to fly than a big, ponderous and slow Hex or Octo Copter in any case.
  7. Leaving the professional people who uses big cameras you are always better off thinking to build a small, light and agile.
  8. Try to build an inexpensive and small Quad Copter.
  9. The easiest way to build is to buy a single kit that has all the parts necessary in one box and a set of instructions for each step.
  10. A good all inclusive kit is the most reliable and straightforward way to construct a quality Multi Copter.
  11. Usually all of the components are well balanced with each other and the entire craft can be expected to perform well.
  12. For an all inclusive kit, assembly is just nuts and bolts and possibly some soldering.
  13. The assembly procedure is usually well explained in the supplied instructions.
  14. The drawback is that quality kits are a bit more expensive and customization has to be done to meet your needs.
  15. If you are not ready to take a risk or not willing to do some hard work, a good all inclusive kit is definitely the best place to start.
  16. Note that some ARF kits that are cheaper are not nearly as sturdy and the components can fail much more frequently.
  17. There are more expensive high quality ARF kits available and they will give great service and have very high performance.
  18. If you want to keep initial cost to a bare minimum, start with a simple Flight Controller then graduate to high end controller when you are ready.
  19. Once you are going to build your own Multi Copter based on scratch built frame kit you have to be cautious, this is really tricky business.
  20. The exception is if you are carefully following a specific and highly detailed build.
  21. Scratch Building is often attempted by those who have never used a multi copter.
  22. In the simplest level a functioning Quad Copter can be built out of sticks or dowels and plywood that will fly.
  23. But it requires a careful construction and lot of turning to fly well or to be serviceable or to well tolerate less than perfect “landings”.
  24. Sometimes this is not the way to save money, RTF, Kits and ARF include high quality matched components sometime actually cost less.
  25. Even if you are an experienced model builder, machinist or engineer,you have to apply full effort.
  26. Multi copters have their whole own set of flight dynamics and structural demands.
  27. Until you have studied them in detail you stand virtually no chance of designing and making a worthwhile Multi Copter.
  28. If you are not very experienced, you will certainly need to make several attempts before you can make a good quad copter and fly it well.
  29. Think about which approach will be right for you.
  30. It is very important to match your approach to your capability level, if you overact you can end up with a negative experience.
  31. It is also much more important to take a robust and conservative approach than to try to do everything the first time out.
  32. A good ARF kit plus some carefully chosen components can also result in an outstanding copter.
  33. The ARF approach can often cost somewhat less and enable you to construct a copter that is specifically tailored to your needs.
  34. The Frame Kit approach presumes that you have sufficient knowledge about the specific components that will work together.
  35. But it does let you put together a copter that is specifically optimized for your needs and desires.
  36. If you find a comprehensive article detailing a specific “build” a Frame Kit can be your first copter.
  37. Actually it is not that hard to build a Multi Copter frame.
  38. But the overall process and component matching and turning to make it work well is really a tough job for a new builder.
  39. There are expensive, high end Multi copters, which are generally oriented to commercial photo or video use and that is not for a beginner scratch builder.
  40. All of the Copters I have and the one I am going to explain are based on cheap and capable flight controllers available and they have good community support.
  41. What should be your Quad copter building goals
  42. Cheap - If you wanted the budget to be near Rs.10,000/- for everything needed to fly. That includes all the basic elements: Frame, ESCs, Flight Controller, Motors, Props, Battery and Radio, etc.
  43. Strong - As for the frame, I aim at something rigid and strong, but not too heavy. I wanted to stay away from the inexpensive ready made frames because if they break I loose my money.
  44. No Soldering - Many people found soldering job messy, unfortunately, ESCs and Motors with bullet connectors already soldered are very difficult to get.
  45. Easy to Tune - The quad copter should be easy to configure and tune. The LCD flight controller which I am going to explain is easy to setup and tune.
  46. There will not be any ground control systems and no complex code to change and flash.
  47. Material selection - For this project I chose to build the quad with PVC pipes because that is one of the most common item avialiable in all local hardware shops.
  48. When we do the construction one of our first and main concerns is weight and most of the weight can be reduced or added just by the frame itself.
  49. With that being said you can't go for powerful motors and any other material because the motors can rip the material apart.
  50. If you want a light weight frame then, you have to consider the box method where you build the arm out of a box shape instead of just a flat piece of material (pipes comes under box).
  51. Another benefit of the box is that you can take your wires inside the pipe leaving less exposed wires.
  52. For using other materials you'll also need to decide what kind of motor and prop system to use.
  53. This can often take some time to select a proper combination as you don't want props that are too big and take to much energy to spin but also not too small where you don't get enough thrust.
  54. Along with the motors you need ESCs, depend on how much current your motors draw.
  55. After the motors and ESCs, select a correct Lipo based on the motor and max AUW you can have.
  56. Then you requires a power distribution board or harness ( you can buy a ready made one or can make one yourself).
  57. The next step would be to select your transmitter and receiver (If you don"t have one).
  58. For the most basic multi-rotor you need 4 channels. These four are for all the basic commands like throttle, yaw, pitch, and roll. Now if you want to add autonomous functionality or control LED lights or any such things on your quad then you need 5 channels or more depending on what you want to do.
  59. The final part you'll need is the flight controller, the microprocessor board fitted with gyro and accelerometer that controls every function in the quad copter from flying to stay stable while hovering.
  60. They're are many different choices for board but the one I chose was KK 2.1.5 LCD Flight Controller.
  61. This board is an easy one for a beginner because of the simplicity of turning.
  62. If you had gone through all the chapters of my blog, then you're welcome to go and try and mix and match parts on you're own.
  63. If not and would like some help you're most welcome to copy my build .
If you understood all the above mentioned points and you want to build your own Quad Copter from scratch, then read the Next post -  Construction of a 550 mm Quad Copter from PVC pipes.  

No comments:

Post a Comment