Controls explained
Arcade Trackballs and Spinners Explained: Which Games Need Them and Should You Add One?
Joysticks and buttons get most of the attention, but a whole category of classic arcade games was built around rolling a ball or spinning a knob. Play them with a joystick and they feel wrong.
This guide explains what trackballs and spinners do, the main features to compare, how they connect to a home cabinet, and whether they are worth the room on your control panel.
Quick answer
- Trackballs give fast, precise two-axis movement for games like Centipede, Missile Command and Marble Madness, plus golf and bowling games.
- Spinners are endless-rotation knobs for games like Tempest and Arkanoid.
- On a PC-based cabinet, both usually connect over USB and act like a mouse.
- Add one only if you play those games. They take panel space and change your layout.
What they are and why games used them
A trackball is essentially an upside-down mouse: a large ball sits in a housing, and sensors measure how far and how fast it rolls in two directions. Players can make big sweeping movements or tiny adjustments, which is why games involving aiming or rolling objects used them.
A spinner measures rotation in one axis and turns endlessly with no stops. Its speed and direction are what matter. Many spinners have a weighted flywheel so a quick flick keeps them turning, which suits games where you sweep a paddle or ship across or around the screen.
A paddle control, used by some very early games, looks similar but is different: it is usually a potentiometer with a limited range and a fixed start and end point. A spinner can stand in for a paddle in many setups, but the feel is not identical.
Which games want which control
| Control | Classic examples | Why it matters |
|---|---|---|
| Trackball | Centipede, Millipede, Missile Command, Marble Madness | Fast aiming and smooth rolling movement a joystick cannot match |
| Trackball | Arcade golf and bowling games | Swing power and direction come from how you roll the ball |
| Spinner | Tempest, Arkanoid | Precise rotation speed for moving around a tube or across the bottom of the screen |
| Spinner + joystick | Tron | Spinner aims while the stick moves |
If none of these games are on your must-play list, you probably do not need either control. If one or two are favorites, the improvement is dramatic. Play the games you have the legal right to play, such as official collections, original boards or titles you own.
Trackball features to compare
Ball size
Arcade trackballs commonly come in roughly 2.25-inch and 3-inch sizes. Larger balls tend to feel smoother and are good for golf and bowling-style games; smaller balls suit cramped panels and quick aiming. Check the exact diameter and the panel cutout required for any model you consider.
Rollers and bearings
The ball rests on rollers, and the quality of those rollers and their bearings decides how smoothly it spins and how long it keeps spinning. Better units feel free and consistent; worn or cheap ones feel gritty or drag.
Sensors
Most modern units use optical sensing. What matters in practice is how responsive and consistent movement feels, which you can tune in software on a PC cabinet.
Mounting style
Trackballs mount either from below the panel, which hides the mechanism but needs a precise cutout and enough depth, or from above with a bezel, which is often easier for DIY panels. Measure your control panel thickness and the space underneath.
Illumination and ball material
Some trackballs use translucent balls lit from below. It looks great, but it is cosmetic. Solid balls are equally functional.
Spinner features to compare
- Flywheel weight: heavier wheels keep spinning after a flick; lighter ones stop sooner and feel more direct.
- Resolution and smoothness: look for consistent, fine-grained movement rather than steppy jumps.
- Knob size and grip: a larger, knurled knob is easier to control quickly.
- Push-button knob: some spinners let you press the knob as a button, which suits certain games.
- Mounting depth: spinners need clearance under the panel for the shaft and flywheel.
How they connect to a home cabinet
On a PC-based cabinet, the simplest route is a trackball or spinner with a built-in USB interface. The computer sees it as a mouse, either two axes for a trackball or one for a spinner, and front-end and emulator software maps that movement to the game.
Some USB encoders and interface boards also accept trackball or spinner inputs; others do not. Check the specifications of your encoder before assuming it will work. Our USB encoder guide explains the common board types.
Two practical tips once it is connected:
- Tune sensitivity per game. One global setting rarely suits every title. Adjust in the emulator or front end until movement feels natural.
- Keep the desktop cursor out of the way. Because it is a mouse, a trackball can move the system cursor. Most front ends handle this, but set it up deliberately so the pointer does not appear mid-game.
Dedicated home cabinets with a trackball built in are a different matter; they work with the cabinet's own software and usually are not meant to be modified.
Where to put them on the panel
Panel space is the biggest cost of adding these controls. Common layouts:
- Trackball centered between the two player areas, below or between the joysticks, so either player can reach it.
- Spinner on the left of player one, or between the players, so the right hand stays on buttons.
- Leave enough gap between the trackball and the joysticks so a hand on one does not bump the other.
Mock up your panel at full size on paper or cardboard before cutting anything. Our guide to control panel mounting patterns and the complete DIY parts list help with planning a full panel.
Desktop trackballs and spinners in their own small boxes exist, and some people simply use a good desktop trackball mouse to test whether they enjoy those games before committing to a panel rebuild.
Buying checklist
Before ordering a trackball or spinner for a home cabinet, run through these questions. They prevent the most common returns and re-cut panels.
- Which specific games will I use it for, and do I already have a legal way to play them?
- Does it include its own USB interface, or does it need to connect through my encoder?
- What size panel cutout does it need, and is my panel thick enough for the mounting style?
- How much depth is under the panel for the housing, shaft or flywheel?
- Where will it sit so both players can reach it without bumping a joystick?
- Can the ball, rollers or knob be replaced if they wear?
For a dedicated retro cabinet built around one trackball game, ball size and smoothness matter most. For a multi-game PC cabinet, ease of mounting and USB compatibility usually matter more.
Care and maintenance
Trackballs collect skin oil and dust on the ball and rollers, which makes them feel sluggish. Occasionally remove the ball as the manufacturer describes, wipe the ball and clean the rollers with a lint-free cloth. Spinners rarely need attention beyond keeping the shaft area clean. If either control stops responding entirely on a PC cabinet, check the USB connection and the software mapping before suspecting the hardware.
FAQ
Do I need a trackball for Centipede and Missile Command?
You can play with a joystick or mouse, but a trackball is how those games were designed, and most people find it far more accurate and fun. If those are favorites, a trackball is worth adding.
What size trackball should I get?
Common arcade sizes are around 2.25 and 3 inches. Larger balls feel smooth and suit golf and bowling games; smaller ones fit tighter panels. Check the panel cutout and depth for the specific model.
Is a spinner the same as a paddle?
Not exactly. A spinner turns endlessly and reads speed and direction. A paddle is usually a potentiometer with a limited range. A spinner can substitute for a paddle in many setups, but the feel is different.
Will a trackball work with my USB encoder?
Many trackballs and spinners have their own USB interface and work as a mouse without an encoder. Some encoders accept them directly and some do not, so check your encoder's specifications.
The bottom line
Trackballs and spinners are specialist controls, and that is exactly why they matter. If the games you love were built around them, adding one transforms how those games feel at home. If they are not, keep the panel space for buttons and joysticks. Decide based on the games you actually play, mock up the layout before cutting, and check that the interface works with your setup.