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+ | ~~NOTOC~~ | ||
+ | |||
+ | <note important> | ||
+ | |||
====== 3S Quadcopter ====== | ====== 3S Quadcopter ====== | ||
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===== The brain ===== | ===== The brain ===== | ||
+ | |||
+ | <note tip> | ||
==== Assembly ==== | ==== Assembly ==== | ||
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- get and install Arduino 0022 (or later) from [[http:// | - get and install Arduino 0022 (or later) from [[http:// | ||
* note that you'll need to have also Java installed | * note that you'll need to have also Java installed | ||
+ | * Arduino 1.0 has been released and seems to contain changes that might break compatibility so it might not hurt to use version 0022 or 0023 instead | ||
- check that your FTDI<> | - check that your FTDI<> | ||
* I'm using [[http:// | * I'm using [[http:// | ||
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- extract the " | - extract the " | ||
- after starting the Arduino SDK, MultiWii should be visible in the load sketches menu | - after starting the Arduino SDK, MultiWii should be visible in the load sketches menu | ||
- | - open the config.h and configure it based on your needs | + | - open the config.h and configure it based on your needs (changes compared to 1.8p2 defaults for FreeIMU v0.3.5_BMP and my setup) |
- | * //this step will be written in more details// | + | * #define MINTHROTTLE 1180 |
+ | * %%//#define INTERNAL_I2C_PULLUPS%% | ||
+ | * %%//#define FAILSAFE%% | ||
+ | * #define FREEIMUv035_BMP | ||
+ | * #define ITG3200_LPF_98HZ | ||
+ | * #define SERIAL_SUM_PPM ... %%// Futaba%% | ||
+ | * %%//#define VBAT%% | ||
- run Verify to check for errors | - run Verify to check for errors | ||
- select the correct Arduino board: Tools -> Board -> Arduino Pro Mini (5V, 16 MHz) w/ ATmega 328 | - select the correct Arduino board: Tools -> Board -> Arduino Pro Mini (5V, 16 MHz) w/ ATmega 328 | ||
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==== Assembly ==== | ==== Assembly ==== | ||
+ | |||
+ | Building the frame starts with cutting four 20 cm pieces of 1 x 1 cm square aluminium tube. Round the sharp edges once cut. The 20 cm length is calculated for a 8" propeller but up to 10" will fit. Accuracy is important while working with the motor arms. Any deviation may result in arms that aren't straight which in turn places the motor in asymmetrical position. This will cause correction need during software tuning and may some times even result in a quadcopter that isn't possible to tune into flying well in all conditions. However, don't worry if the lenghts of the arms don't come exactly identical. Getting the lengths withing few millimeters is enought. It's more important that the holes have equal distances in each arm and are correctly aligned. | ||
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+ | The table below shows the distances for the 3 mm mounting holes that are needed for attaching the baseplates (first 3) and the motors (last 2). All measurements are made from the beginning of the arm so slight deviations in arm lenghts will not matter as long as all arms are at least 20 cm in lenght. One 6-8 mm hole may need to be drilled between the two motor mount holes if the motor shaft doesn' | ||
+ | |||
+ | ^ 3 mm mounting hole distances ^^^^^^ | ||
+ | | 10,8 mm | 21 mm | 40,5 mm | --- | 160 mm | 192.7 mm | | ||
+ | |||
+ | Note that I'm using the cross shaped mounting piece for the motors. The reason is that the mounting holes in that piece are symmetrical resulting in free orientation of the motor. The other mounting holes that are directly in the motor aren't in a symmetrical pattern and the orientation seems to be random. Because I want to have the motor wiring point to a specific direction (=away from the front), using the direct mounting holes isn't an option. The cross shaped mounting piece appears to be somewhat standard since my other motors also have exactly the same spacing. Additional, it may provide a little bit of extra protection for the motor bell. Any hits from the sides will first make contact with the mount instead of the motor. | ||
+ | |||
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+ | |||
+ | ^ Screw and nut list ^^^ | ||
+ | | 4 | 20 mm M3 metal screw| inner baseplate | | ||
+ | | 4 | 40 mm M3 metal screw| outer baseplate, landing gear, something 15-20 mm longer can also be used | | ||
+ | | 8 | 18 mm M3 metal screw| motor mount | | ||
+ | | 4 | M3 metal washer | for the landing gear screws | | ||
+ | | 16 | M3 metal nut | replace with locknuts during final assembly | | ||
+ | | 28 | M3 nylon nut | use with nylon parts, replace with metal nuts if not available | | ||
+ | | 4 | 30 mm M3 nylon screw| MWC shield mount | | ||
+ | | 4 | 20 mm nylon standoff | optional, for the cover plate | | ||
+ | |||
+ | Now is a good time to do a test fit. Connect the arms to the baseplate with two M3 screws (first and third mounting hole) for each arm. Use normals M3 nuts instead of locknuts in order to ease the eventual disassembly. Attach the MWC shield with M3 nylon screws using few layers of nylon nuts to rise the shield slightly from the baseplate. Connect the cover plate with polyamid stands or something similar. Before attaching the motors, check that the frame doesn' | ||
+ | |||
+ | ==== Power distribution ==== | ||
+ | |||
+ | The baseplates sold by [[http:// | ||
+ | |||
+ | Disassemble the frame and take the power distribution plate in view. Notice the layout of the connection pads. From the motor arm point of view, the positive and negative pads aren't always on the same sides. As a result, in order to connect the ESCs correctly, 2 ESCs will have the wires crossing each other while 2 ESCs will have wires going straight to the pads. Shortening the wire may not be necessary. It's better to have the wires doing an S shaped figure instead of going straight to the pads without flexibility. Solder the ESCs in place and also add power wires for the battery starting from the bigger pads in the center of the plate. Orientate the power wires going for the battery towards the back and use two zip ties crossing each other to connect the power wires to the outer rim of the baseplate. That way, pulling the wires will pull the frame instead of the solders. | ||
+ | |||
+ | Using one motor arm with the motor attached as a template, figure out how much the three ESC wires going to the motor need to be cut shorter. With the Hobbywing 10A ESCs, I had to shorten the ESC wires by 7 cm each. I did a test about using the bullet connectors that came with the motors but found that those connectors are some loose and somewhat overkill considering the size of the wires. I ended up using much smaller [[http:// | ||
+ | |||
+ | The ESCs should now be connected to the baseplate and connections to motors ready. | ||
+ | |||
+ | ^ ESC setup ^^ | ||
+ | | Brake | OFF | | ||
+ | | Battery Type | Li-xx | | ||
+ | | Cut Off Type | Soft-Cut | ||
+ | | Cut Off Voltage | Low | | ||
+ | | Start Mode | Normal | ||
+ | | Timing Mode | Middle | ||
+ | | Music | OFF | | ||
+ | | Governor Mode | OFF | | ||
+ | |||
+ | While playing with the motors (without propellers!), | ||
+ | |||
+ | Balancing any rotating parts is one key element in getting a well flying quadcopter. Remember to also balance the propellers. So far I haven' | ||
==== Let there be light! ==== | ==== Let there be light! ==== | ||
+ | |||
+ | This is an optional step. Lights help keeping track of the orientation of the quadcopter especially when flying high or in poor visibility. | ||
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