SINCE THIS HOBBY REQUIRES SO MUCH BUILDING, NATURALLY THERE IS A WIDE VARIETY OF TOOLS THAT MUST BE OWNED in order to be able to build and maintain a helicopter. Even though there is a vast number of tools that can be used, there are only a core few that required to get the job completely done. Those core sets of tools are widely seen at every flying field and shouldn’t be left out of the anyone’s toolbox. In this Tools of the Trade, we will break down seven very important tools that will help build and maintain your helicopter at all time. The Hex drivers is one of most important tool to maintain your helicopter. It is perhaps the most important set of tools in your toolbox. Hex drivers are used for just about everything. In most modern-day helicopters, all bolts have a hex head on them that makes them easier to tighten and remove. The most common sizes are 1.5mm, 2.0mm, 2.5mm, and 3.0mm. It is very common to see 2.5mm heads on almost all applications on larger helicopters. 3.0mm heads are used for items such as spindle bolts and blade bolts. 2.0mm heads are seen on specific applications that vary from helicopter to helicopter. 1.5mm heads are usually the universal hex driver on micro-helicopters.