Spinners and Dials

What is a Spinner?

You might remember the spinner from games like Tempest and Arkanoid. The player turns a knob to move the on-screen character. But what's going on behind the scenes; what's that knob attached to?

Underneath the control panel, the shaft comes down from the knob above. Mounted on the shaft, is an optical encoder wheel- a flat disk with notches cut around the outside edge. These notches pass though a set of infra-red optics, that detect the notches as they spin by. There are two sets of optics, spaced such that they see the notches spin by just a little bit out of sync. The combined signal from both of these optics tells the game which direction the disk is turning, and how fast. This is also how a trackball works, as well as a ball-type PC mouse.

Varieties of Spinner

There have been lots and lots of different spinners manufactured over the years. A few of the more common, or more interesting ones are listed below.

1. Tempest- The spinner against which all others are compared. 72 teeth on the encoder wheel, with nylon upper and lower bearings on the shaft. This was the model for the Oscar Vortex.

1. Arkanoid- The "geared" spinner. Rather than mounting the encoder wheel directly to the shaft, the Arkanoid spinner used two sets of gears between the knob and the encoder wheel, to make the spinner extremely sensetive. While the encoder wheel only has 24 notches, the gearing causes 486 notches to psss through the optics for every turn of the knob! The Arkanoid spinner also has no weight to speak of, so it stops the instant you take your hand off the knob.

1. Discs of Tron- This spinner used a giant 128-notch encoder wheel. But the really interesting part is the up/down feature. When the player pulled up or down, a leafswitch was activated. This was used to control the aim of the disc in later levels of the game. Oscar made a Push/Pull spinner with a slightly different design, and a smaller 72 notch encoder wheel. Zwackery also used a Push/Pull spinner, and Forgotten Worlds used a push only (no pull) spinner. The Oscar V2 had a Push option, and a Pull kit was rumored to be in the works before Oscar Controls closed down.

1. Oscar- Oscar isn't a specific spinner; Oscar Controls was a manufacturere of spinners to the hobbyist market until recently. Several models were produced over the years, including the Model One, Pro, Vortex, Push/Pull, and V2.

1. SlikStik Tornado- Billed as the "longest spinning" spinner on the market, the Tornado is now the spinner that's been on the market the longest. With an extra-small footprint, and dual-bearing design, the Tornado is very well made. Several knob options are also available. The Tornado comes with it's own USB or PS/2 interface. Plans to sell the Vortex with a plain-jane optic card have also been announced.

1. GroovyGameGear TurboTwist- New to the market, the TurboTwist also has a small footprint and a dual-bearing design. The TurboTwist has an extra-high resolution encoder wheel, and comes with it's own USB or PS/2 Opti_Wiz interface. The interface can be configured to put the spinner on the X, Y, or Z mouse axis, and will control other optic devices on the remaining two axes, such as a trackball, or additional spinners/steering wheels/optical rotary joysticks. A plain-jane optic card version has also been announced.

1. ArcadeGames4U Cyclone- Also new to the market, the Cyclone has a dual-bearing design, with a lower resolution encoder wheel. The Cyclone ships with an optic card, but no interface.

1. Build Your Own!- Many users have build their own spinners from whatever parts they had available- Hard drive bearings, skateboard bearings, whatever. Use your imagination!