This flyer was only getting 3 minutes of flying time on his batteries. It turns out he had telemetry readout of his instantaneous battery voltage, and he had set the alarms at too high a voltage. Here is his description, and my response. Your thresholds are set too high. 3.7 volts is too high - that's roughly the 80% discharged level of a Lipo. 3.5 or 3.4v is considered the "fully discharged" level. Take a look at this thread for voltage versus discharge curves.

Second, your measurement includes the voltage drop when you are pulling amps. That voltage drop is not accurately representing the true battery voltage. When you are at full power, the V drop could be 1.2volts (0.3 volts per cell equivalent). That means the voltage at the battery is 1.2 volts higher than it is at the measurement point. So a few beeps when you goose the throttle does not mean it's time to come down. (...Continue Reading

Here's what I wrote in response to a review of a kit of parts from RTL fasteners. I'll try to supplement it with a specific list of exactly what I got, and what I wish I had gotten.

After reading a review of RTL's non-metric assortment, I was able to put together my own (metric) collection for about $70, from http://www.trimcraftaviationrc.com. I got sizes from M2 to M4, with a variety of ends and lengths. I also combined it with a set from Harbor Freight that had a storage box and large sizes - M5 and up.
Trimcraft charges only $3 for any amount of shipping, and for small amounts they send it First Class mail.
A few comments, wherever you source from. Others with more building experience than I have can probably do better.

• The metric numbering system is even better than you suggest. Mn means diameter is n millimeters. So an M3x8 weighs and has strength roughly 2.25x an M2 x 8. (3 squared = 9; 2 squared = 4)
• I should have gotten a few M1.5s (1.5 mm)
• I got both Phillips head bolts, and Socket head cap. Phillips are easier to use, but for some reason I feel more secure with the socket head. There are various other kinds of heads available.
• It's more useful to get a wide range of lengths than to get every possible length in a range. Usually you can make something fit if it's a few mm too long, but if you need 30mm and you only have 25, you are out of luck!
• I should even have gotten some Phillips M4 x 40 and possibly M4 x 50. I was trying to use plywood on the inside of a fuse to brace something fastened to the outside.
• Keep the parts in the bags and cut a hole in the corner.
• I followed RTL's list and got some non-metric screws such as Servo Mounting Screws #2x7/16" . For some reason it's harder to find metric screws than bolts. The screws are very useful e.g. for cowl mounting.