Editing Stabiliser (section)

==Design==
Many stabiliser designs have been used over the years. The common varieties are as follows:

===Wire===
The most common design is the wire stabiliser. A stiff wire runs from one end of the key to the other, connected to the keycap at each end, and to the keyboard plate or PCB via some form of restraint. The wire pivots against both the keyboard and keycap; pressing one end of the key rotates the wire, and the other end of the wire pulls its end of the keycap down accordingly. More than simply keeping the keycap moving vertically (important to prevent [[binding]]), this method actively keeps the keycap level.

This forms the basis of the stabiliser designs used by Costar, Cherry, SMK, and some of those from Alps and IBM.

The compound stabiliser design used in the [[Zenith Supersport SX]] for the enter key (shown below) is subject to Alps patent [https://www.google.com/patents/US4771146 US 4771146], filed in 1987 and with a priority date of 1985.

<gallery widths=250 heights=187>
File:Stabilised key.jpg                                            | Wire-stabilised key
File:NTC 6752-EA -- caps removed.jpg                               | [[NTC KB-6752EA]] internals, showing stabiliser wires
File:Zenith Supersport SX -- Enter key stabiliser.jpg              | Zenith Supersport SX enter stabiliser, Alps-patented
File:Zenith Supersport SX -- Enter key stabiliser disassembled.jpg | Zenith Supersport SX enter stabiliser disassembled
</gallery>

===Dummy switch===
This design pairs a normal switch with a dummy switch. This approach has been used by Micro Switch for their Hall effect keyboards, as well as in [[ITW magnetic valve]] keyboards.

In the case of the ITW design, the stabiliser dummy switch feels quite light and seems to have low [[preload]].

===Guide shaft===
Some manufacturers such as Alps and Fujitsu used guide shafts for some or all large keys. A plastic insert is fitted, bearing a guide shaft, and a plastic post within the keycap fits into this shaft. This approach is not always successful; the Fujitsu FKB4700 is infamous for the poor quality of its stabilisation. However, this approach works well in IBM Model M keyboards.

<gallery widths=250 heights=187>
File:Apple M0118 Return.jpg                                        | [[Apple M0118]] return key, with guide shaft stabiliser
File:Fujitsu FKB4700-152 -- supernumerary traces and domes.jpg     | [[Fujitsu FKB4700]] enter key switch and guide shaft insert
</gallery>

===Dual switch===
The SMK-made "Type 2" keyboard for the [[Acorn BBC Microcomputer]] has been found with a pair of light weight switches under the return key. [[Matrix layout]] [[POS]] keyboards allow keycaps to span multiple switches in 1×2, 2×1 and 2×2 arrangements; here, the keys will be substantially heavier as a result.