Here 's a handy tip for you quad builders

[G+_Donald Burr]

Here's a handy tip for you quad builders.  If you are afraid of firing up your quad for the first time... maybe you accidentally created a short circuit somewhere while wiring things up, accidentally created a solder bridge between two things that should NOT be connected, etc., and you're worried that you might end up setting your LiPo pack on fire, here's a tip for you.  If you can, find yourself a lab-grade switching DC power supply, especially one with overcurrent and overvoltage protection.  If you have a friend who's into electronics he/she probably has one, or you can usually find one in a reasonably well equipped electronics lab (e.g. at a university or community college)  Hook your quad up to it instead of your LiPo battery, set the power supply's output voltage to the same as your LiPo pack (should be written somewhere on your pack, typically 11.1 volts for a 3-cell pack) and dial in the overcurrent protection to something like 500 mA, then fire up your quad.  If all is well then you should be able to exercise some of its functions (rev some motors, talk to your flight controller, etc.)  And if you screwed up in your wiring somewhere, the overcurrent protection should kick in and hopefully prevent any damage to your quad.  But, at the very least, at least you won't blow yourself up if you ended up wiring something wrong.

 

BTW if you're at all interested in electronics, a power supply such as this is really handy to have.  It lets you apply power in a controlled manner to a circuit you are working on.  There are some really fancy ones that run in the hundreds of dollars, but there are also some really good basic units that may not have all the bells and whistles of the fancy ones, but do the job.  I got one new on Ebay for about $60; search for "CSI3003SM"  It's a basic no-frills unit capable of delivering 0-30V and 0-3A, with overcurrent and overvoltage protection, and is more than enough for the basic hobbyist.

 

Also, it's probably obvious, but having a multimeter around while building is REALLY handy, especially if it has a "continuity test" function.  Basically this causes the multimeter to beep when there is a valid electrical connection between whatever you're touching the multimeter's probes to.  This is really handy to use as you're building your quad, so that you can test to make sure that things that are supposed to be connected are connected (e.g. your solder joints are right and proper), and more importantly, things that SHOULDN'T be connected to each other aren't.  Multimeters are pretty inexpensive nowadays (you can get some no-frils models that have all the basic functions for under $20).

[G+_Eddie Foy]

I rarely use the beep function.  With moderately high resistance, it won't beep but still be bridged.  I always check the actual ohms.  Been bitten early on in my career.  Also touching both probes (the metal tips) at the same time will give false readings since your body is creating a parallel resistor network thus reducing the actual resistance of the measured 'device'.

[G+_Eddie Foy]

Also spend the extra $ and get auto-ranging DDMs. Having it set to the wrong range can let all the smoke out (That's ok, if you have a smoke re-installation kit handy, but I never seem to :P )