While I was poking around about what kinds of cool things people do with an Arduino, I stumbled across AeroQuad. It’s a site and community for folks who are developing an open-source multi-rotor RC helicoptor.
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| An AeroQuad (pic courtesy AeroQuad.com) |
Now that’s awesome.
As soon as I saw that, I thought to myself “Dude, you totally have to make one of them!”. Cue the research frenzy, cost analysis, and wife justification strategies (love you, snookums). And guess what, it looks like it’s pretty viable, and should make a great project to get me back into electronics and also leave me with something totally awesome at the end of it.
So, in order to make a Quad, there’s quite the number of items that are required. Later posts will detail just how I’ve gone about actually getting those items and putting everything together into a (hopefully) working quadcopter;
- A work area. My shed’s a storage disaster. So the need for a work area has triggered off a cleaning frenzy of throwing out lots of stuff, installing shelving to get boxes off the floor, and I also charged out and bought all the stuff to build a (wooden) workbench. The bench I’ll discuss in brief later.
- A variable power soldering iron or a 15W and a 30W iron. I only owned a 40W iron, which is a bit hefty for delicate electronics on sensors, so I picked up a $99 soldering station from Jaycar. According to the salesman, the “temperature control” actually just varies wattage, so it can stand in for a 15W iron.
- Arduino UNO. You can also use an Arduino Mega for more sensors, but I want to start small and simple. I got a Uno with my Inventor’s kit, but I’ve ordered a second off eBay.
- AeroQuad Shield. This is a board that sits on top of the Uno and provides connectivity to the sensors. It’s not technically required, but I just got the v1.9 board from the AeroQuad store to get it over and done with.
- Nintendo WiiMotion Plus. The WMP has a 3-axis gyroscope in it, which is useable with AeroQuad, and is pretty damn cheap. I picked up one from eBay, and am planning to use it in the build. There’s been reported issues with AeroQuad 2.4 software and Wii components, but it’s a work in progress and being fixed.
- Nintendo Wii Nunchuk. The Nunchuk has a 3-axis accelerometer in it, which goes with the WMP and the shield to make a 6DOF IMU (inertial measurement unit). These three items make the navigation heart of the AeroQuad. The Mega can also take a barometer, magnetometer and such for even better navigation.
- Miscellaneous Cabling & Stuff. Various connectors and stuff are required, I’ll get them as I need them.
- Frame. I haven’t bought the frame components yet, since they aren’t needed in the early stages. But I’m planning on using a X of square-section aluminium tube for the arms, with a plastic case for the electronics. Motor-to-motor diameter will be about 20-24 inches.
- Battery. Not required just yet, but a main 3S1P LiPo (lithium-polymer) battery is required to drive the motors. I’ll probably aim for a 4000mAh version. Most advice seems to be to pick a 3S1P battery (11.1 volts) which weighs about the same as the rest of the quad.
- Charger to suit Battery. Not required yet, but a charger with an automatic balancing feature is pretty key, especially with LiPo’s which tend to explode if they’re badly charged.
- Propellers. Not required yet. They have to be balanced and in counter-rotating pairs. I’ll probably be going with cheapo 10x6 inch props, since I’m likely to break heaps.
- ESC’s. Not required yet. Electronic Speed Controllers drive the main motors at a speed as governed by the servo connection on them. They’re basically like a relay, but variable. The DC brushless motors used in a quad can draw a lot of current, and given the motor/prop combo I’m probably going with, I’ll likely be getting Turnigy Plush 25A ESC’s.
- Motors. Not required yet. Motor/Prop combination is a bit tricky, and also relies on the size and mass of your quad. I figured out that the Turnigy 2217-20 motors should give me the thrust I want (3kg, which will be a bit more than double the weight of the quad), while not overdriving the ESC’s.
- Transmitter and Receiver. I wound out ordering a HobbyKing HK-7X radio and receiver. Honestly, I would have preferred a Spektrum DX7, but they are very expensive, and I just can’t justify the money on a first quad. As long as the HK-7X actually works, it should be $60 well spent. I can go with the Spektrum later, if I wind up getting more models or need the better quality.
I’ve ordered in all the electronics - so that’s the controller, IMU components, and Tx/Rx. I’ll wait until I’ve settled on a frame and have a better idea of weight before I start ordering ESC’s, props and motors. I’ll have plenty to play with in the meantime.
So as you can imagine, I’m impatiently awaiting my parts arriving.