If you're reading this there's a good chance you've spent a good part of your life with your hands on any number of joysticks. A lot of players are now dreaming of their own custom sticks. When placing orders or discussing changes it's important to know the proper terminology. This is the anatomy of a joystick, with the part names used by Japanese joystick manufacturers Sanwa and Seimitsu.

Sometimes called lever ball, or knob. Almost always removable, and they all share the same thread so they're swappable. If your ball can be removed there's very little chance it can't be replaced with any other. There are several sizes, ranging from a tiny 30mm to a ridiculous 49mm. The standard size is 35-40mm. There are different shapes available, the most common alternative being a bat handle (called a Nasubi lever ball, made by Sanwa), and you can also use the SNK ball or the weird SNK teardrop shaped knob from the CD-style stick.

The shaft tends to be matched to the mechanism. You'll rarely be able to swap one shaft with another from a different mechanism, even from the same manufacturer.

Also called a dust disc. This is the bit that keeps you from cutting chunks off your finger when you move the stick against the panel hole. Most disks will fit most shafts, and the outside diameter rarely changes (normally about 40mm), except for large, Virtual On-style sticks. The VO disks also have a very large inner diameter, so they're useless for normal sticks.

This is the fulcrum, and when your stick starts sticking in one direction or another, this is the part you should clean and add some lithium grease to.

This is usually little more than a plastic shell to which all other parts are clipped or screwed. There are several compatible patterns and spacing for the screws mounting the base to the panel, but as a rule you should assume the new mechanism will be different just to irritate you. Many bases have additional mounting plates. Most home sticks mount the base from below so there are no holes in the panel. This makes it near impossible to exchange one base for another without drilling holes where there weren't any before.

In the Sanwa catalogue the top cap is an S.P. Pipe, the bottom is a P.S. Pipe. I prefer to call them the top and bottom spring caps, since in English the word 'pipe' conjures up a rather different looking part. The bottom cap can sometimes be called an actuator, since it's the part that actually contacts the switches.

Usually microswitches, but often leaf switches and occasionally optical. You'll rarely find analogue joysticks except in specialized arcade applications.

The gate limits the movement of the bottom spring cap and determines the range of movement of the stick. Many joysticks have adjustable gates, rotatable to select four or eight way stick movement. Some sticks from Seimitsu have a single guide that can select two, four or eight way movement. Sanwa sticks that can select at all are usually limited to four and eight, though Sanwa sticks without an adjustable guide often have replacement guides available.