Editing Futaba MA series

{{infobox dswitch
| image name          = Futaba_switch.jpg
| manufacturer        = [[Futaba]]
| switch type         = Clicky, linear, alternate action
| switch mount        = [[Plate mount]]
| keycap mount        = Proprietary<br>[[Cherry MX mount]]
| actuation force     = 60±25 gf, 80±25 gf
| travel              = 3.8±0.5 mm
| lifetime            = 50M, 10M with LED, 100K(Lock)
}}

'''Futaba MA series''' (formerly '''Futaba clicky switch''') is a series of keyboard switches produced by [[Futaba]] and [[Sejin Electron]]. The most common form taken is that of a medium stiff, tactile, clicky [[stacked spring]] switch. The series encompasses light and heavy weights, click feedback, illumination and alternate action variants.

==Nomenclature==
Discovery of several model numbers shows the common portion of the codes to be "MA", and as such this is being taken to be the series name until such time that documentation surfaces. The previous name of "Futaba clicky switch" was chosen to distinguish MA series from the various first-generation types collectively classified as [[Futaba linear switch]]. While MA series remains conjecture, it provides a name that covers the apparent linear types (heavy momentary) and alternate action types.

==History==
The Futaba clicky switch (provisional name to differentiate it from their earlier [[Futaba linear switch|linear switches]]) was a keyboard switch produced by the Japanese company Futaba. It was in many Korean keyboards, mainly by [[Sejin Electron]]. In the foreign market, the keyswitch was first sighted in a 1986 keyboard made by [[Datacomp]] in Taiwan. Many Japanese keyboards also made use of the Futaba keyswitch. The last keyboard known to be produced with Futaba switches was the [[Sejin Electron SKM-1040]] left-handed full-size keyboard, which has been re-branded under many different names. Futaba keyboard switches are no longer in production, and Futaba believe that no records remain of any keyboard switch types.

==Details==
MA series switches are branded "Futaba" on the bottom. Confirmation of identity requires de-soldering the switch from the keyboard. The switch shell is held closed by melted pins; the switch would require glue to reassemble it once the pins have been destroyed. The switch has three legs, in an asymmetric arrangement relative to the branding, with two legs on the left (top-left and bottom-left) and one on the centre right. The top-left and right legs are connected together.<ref name="KBT-EAT-1010" />

The same keycap mount and slider design was later used for the [[Sejin Futaba-mount dome]] switch, which used [[rubber dome]]s over membrane.

The clicky versions use a [[stacked spring]] arrangement.

==Variants==
[[File:Switch recognition--Futaba--Clicky U mount.svg|right|thumb|Futaba [[keycap mount#Cherry MX mount|Cherry MX-mount]] variant]]

Known variants include:

{| class="wikitable variants-table"
! !!Sub-type!!Type!!Keycap mount
|-
|[[File:Futaba clicky switch, old -- front.jpg|175px]]|| ||Momentary, clicky||Futaba (old?)
|- 
|[[File:Futaba clicky switch, old, heavy -- side.jpg|175px]]|| ||Momentary, clicky||Futaba (old?)
|-
|[[File:NEC PC-8801mkII -- latching action switch, close-up.jpg|175px]]|| ||[[Futaba MA series alternate action|Alternate action]]||Special
|-
|[[File:Futaba MA41 Futaba mount variant.jpg|175px]]||MA-41||Momentary, clicky||Futaba
|-
|[[File:Futaba MA41 MX mount variant.jpg|175px]]||MA-41||Momentary, clicky||Cherry MX
|-
|[[File:No photograph.svg|175px]]
|MA-42
|Momentary, linear
|Futaba
|-
|[[File:No photograph.svg|175px]]
|MA-42
|Momentary, linear
|Cherry MX
|-
|[[File:No photograph.svg|175px]]|| ||Momentary, heavy||
|-
|[[File:Futaba lock -- top.jpg|175px]]||MA-4A||[[Futaba MA series alternate action|Alternate action]], Lock||Special
|-
|[[File:No photograph.svg|175px]]||MA71||Illuminated, clicky||
|-
|[[File:No photograph.svg|175px]]||MA72||Illuminated, linear||
|}

Most Futaba clicky switches have an inverse cross mount, i.e. the cross is on the [[keycap]], and the slot is in the [[slider]]. The keycap stem and the slider each have a two-stage mount, with a smaller cross followed by a larger cross. These switches have been found with white and cyan sliders. Sejin-made keyboards typically use this slider.

There is also a much less common variant with a Cherry MX-compatible slider; these are found in several Chicony keyboards (including some [[Chicony KB-5161|KB-5161]] and some [[Chicony KB-5181|KB-5181]]) and in some Focus keyboards.

The keycap mount is not believed to be indicative of any difference in keyfeel.

The slider colour does have significance, but the details of which are not well documented. Cyan and blue are reported to feel and sound different.<ref name="KBT-EAT-1010" /> At least two keyboards have been found with a stiffer switch used for the space bar, with a dark grey slider<ref name="ScarFace" /><ref name="Microweb" /> or a cyan slider<ref name="Packard Bell XT" />.

There is also what appears to be an older variant with a different slider. This variant is welded closed along the sides, and is found in the [[NEC PC-8801-KI]].

==Specifications==
Four series, model or part numbers have been recovered, along with their specifications.<ref name="ePartsHub-MA41-MA42" /><ref name="ePartsHub-MA71-MA72" />

The keycap mounts for these switches are neither described nor depicted, and the well-known latching version is not listed.

{| class="wikitable row-headings"
!Characteristic!!MA-41!!MA-42!!MA-71!!MA-72
!MA-4A
|-
|Action|| colspan="4" |Momentary
|
|-
|LED|| colspan="2" |No|| colspan="2" |Yes
|
|-
|Tactile feedback||Yes||No||Yes||No
|
|-
|Operating force|| colspan="4" |60±25 gf, 80±25 gf
|
|-
|Travel|| colspan="4" |3.8±0.5 mm
|
|-
|Pretravel|| colspan="4" |0.8 mm or more
|
|-
|Overtravel|| colspan="4" |0.7 mm or more
|
|-
|Bounce time|| colspan="4" |5 ms max (throughout lifetime)
|
|-
|Mounting pitch|| colspan="4" |19.05 mm
|
|-
|Lifetime|| colspan="2" |50M|| colspan="2" |10M
|
|-
|Specification||FS-6015A4||FS-6016A4||FS-6007A7||FS-6016A7
|
|}

The MA-41 [sic] switch specifications are also found in the [[:File:Sejin Electron SKM-2040 User's Manual.pdf|Sejin Electron SKM-2040 User's Manual]]; here the switch lifetime is given as 10 million cycles, and the bounce time as 10 ms.

The specifications are written out as unformatted text, which loses some clarity. As a consequence, the distinction between MA41 and MA42, and MA71 and MA72 isn't clear. Since the heavier space bar switches in keyboards do click, the reasonable interpretation is that both weights apply to each of the clicky and linear switches.

The existence of a momentary linear version of the switch has long been in dispute. [[Sejin Electron SKM-1040]] is specifically reported by a reseller to be linear, and this would fit in with the interpretation of MA42 as the linear equivalent to MA41. Most reports of linear<ref name="Linear" /> and tactile<ref name="GH_nctactile" /> versions of the switch are likely referring to worn switches that no longer click.<ref>YouTube — [https://www.youtube.com/watch?v=VJwxug4DNj4 Sejin 2040LH Futaba Switch]</ref> Such switches have never been examined internally as they cannot be opened non-destructively.

The [[Futaba MA series alternate action|alternate action version]] is however confirmed to use a different contact arrangement that appears to be linear, and this may be what is used inside MA42 and MA72.

==Keyfeel==
The Futaba switch design typically encountered is a clicky and tactile switch. The keyfeel has high hysteresis, with the actuation click occurring around 2.5 mm into the approximately 4 mm travel, and the release click occurring at 1 mm from the home position. The switch is very smooth, with a gentle rise in force, and only a small decrease in force after actuation. The switch has been demonstrated to have a loud ringing sound on a variety of pitches, like a higher-pitched [[IBM Model F]].<ref name="YouTube-SKM-2001" />

==Keyboards==

===Early type===
*[[NEC PC-8801-KI]]
*[[NEC PC-8801mkII]]

===Later type===

====Clicky====
'''Proprietary / White Inverse Cross mount'''
*Some [[Chicony KB-5160]]
*[[Datacomp DFK-501F/502F]] (cyan for space bar, grey for enter)
*[[Datacomp DFK555 | Datacomp DFK-555]]
*[https://deskthority.net/f-o-r-s-a-l-e-f58/datacomp-with-plate-mounted-clicky-futabas-t17597.html Datacomp DFK-777F]
*[[Microweb Touch-1]]
*Olivetti M15 Laptop<ref name="olive"/>
*Packard Bell XT keyboard (Sejin Type #: M7US02X-20, FCCID: GJJ4AKM-8700DE)<ref name="eBay-Packard-Bell-XT" />
*[[Sejin Electron EAT-1010]] (cyan/grey for space bar)
*[[Sejin Electron SKM-1040]] & SKM-1080<ref name="Sejin_1080"/>
*[[Tatung TCS-5000]]

'''Cherry MX mount'''
*Some [[Chicony KB-5161|Chicony KB-5161/5162]]
*Some [[Chicony KB-5181|Chicony KB-5181/5182]]
*Some [[Chicony KB-5191|Chicony KB-5191/5192]]<ref name="Chicony KB-5191" />
*[[Focus FK-1001]]
*Some [[Focus FK-6000]] & [[Focus FK-8000|FK-8000]]
*Some [[Leading Edge AK-1012]]
*Sigma APO System AFK-7711<ref name="sigma"/>

====Linear====
*[[Sejin Electron SKM-1040]]

==Gallery==
===Futaba mount variant===
<gallery widths="250" heights="187">
File:Datacomp DFK555 Futaba switches.jpg                                  | Futaba switches in a Datacomp DFK555 keyboard
File:Futaba clicky switch -- disassembled (1).jpg                         | Disassembled switch
File:Futaba clicky switch -- disassembled (2).jpg                         | Additional view of the internals
File:DataComp DFK-700F2 keyswitch close up.JPG                            | Cyan space bar switch in a [[Tatung TCS-5000]] keyboard
File:Sejin_Electron_EAT-1010_spacebar_switch.jpg                          | Grey space bar switch in a [[Sejin Electron EAT-1010]] keyboard
</gallery>

===Cherry MX mount variant===
<gallery widths="250" heights="187">
File:Futaba clicky switch, Cherry MX mount.jpg                            | Cherry MX mount variant
File:Futaba clicky switch, Cherry MX mount -- base.jpg                    | Base showing branding and asymmetric leg arrangement
File:Futaba clicky switch, Cherry MX mount -- rear.jpg                    | Rear
File:Futaba clicky switch, Cherry MX mount -- left side.jpg               | Left-hand side
File:Futaba clicky switch, Cherry MX mount -- side with exposed metal.jpg | Right-hand side with exposed metal
File:Futaba clicky switch, Cherry MX mount -- keycap 1.jpg                | [[Tai-Hao]] Cherry [[double-shot molding|doubleshot]] fitted
File:Futaba clicky switch, Cherry MX mount -- keycap 2.jpg                | Bottom view of switch and keycap
File:Futaba clicky switch, Cherry MX mount -- keycap 3.jpg                | Switch and keycap
</gallery>

===Early version===
The following is not confirmed to be the same switch as the regular Futaba clicky switch, as the internals are not known to be documented.

The switch is designed to support an external conical spring to provide extra weight.

<gallery widths="250" heights="187">
File:Futaba clicky switch, old -- front.jpg                               | Front
File:Futaba clicky switch, old -- side.jpg                                | Side
File:Futaba clicky switch, old -- heavy and normal, top.jpg               | Heavy and normal, top
File:Futaba clicky switch, old -- heavy and normal, front.jpg             | Heavy and normal, front
File:Futaba clicky switch, old, heavy -- side.jpg                         | Heavy, side
File:Futaba clicky switch -- early design -- side.jpg                     | Side view, showing welded shell
File:Futaba clicky switch -- early design -- base.jpg                     | Base view
File:NEC PC-8801mkII -- external key springs.jpg                          | Two different gauges of external spring (ca. 0.25 mm and 0.5 mm) giving 20 gf and 190 gf extra force respectively (from an [[NEC PC-8801mkII]] keyboard)
</gallery>

==References==
<references>
<ref name="ePartsHub-MA41-MA42">ePartsHub — [http://www.epartshub.com/company/companyForm.do?method=getCompanySeries&cmpyCd=00001257&seriesCd=SR0002191&classCd=XEA1252000&parentCd=XEA0540000 MA41,MA42]</ref>
<ref name="ePartsHub-MA71-MA72">ePartsHub — [http://www.epartshub.com/company/companyForm.do?method=getCompanySeries&cmpyCd=00001257&seriesCd=SR0002190&classCd=XEA1252000&parentCd=XEA0540000 MA71,MA72]</ref>
<ref name="YouTube-SKM-2001">YouTube — [http://www.youtube.com/watch?v=FxaQ9Gte-oY SEJIN SKM-2001 ADB KOREA FUTABAスイッチ キーボード] Dated 2012-06-01. Retrieved 2015-07-26.</ref>
<ref name="eBay-Packard-Bell-XT">{{dead|eBay — [http://www.ebay.com/itm/190796348454 Vintage Packard Bell XT Keyboard Made in Korea Works]}}</ref>
<ref name="KBT-EAT-1010">KBtalKing — [http://kbtalking.cool3c.com/article/6404 ■鍵盤史的遺跡SEJIN EAT-1010(FUTABA軸)■] (Chinese only) Dated 2009-01-08. Retrieved 2015-07-26.</ref>
<ref name="ScarFace">ScarFace Keyboard — [https://m.cafe.naver.com/sfkey/375 리딩엣지 - AK 1012] (Korean only) Dated 2010-02-05. Retrieved 2015-07-26.</ref>
<ref name="Linear">Deskthority — [http://deskthority.net/keyboards-f2/futaba-or-modern-equivalent-t6411.html Futaba or modern equivalent]</ref>
<ref name="GH_nctactile">Geekhack — [http://geekhack.org/index.php?topic=8187.30 new in box alps] Posted 2009-12-20. Retrieved 2015-07-26.</ref>
<ref name="Microweb">Deskthority — [http://deskthority.net/photos-f62/microweb-touch-1-t8619.html Microweb Touch-1]</ref>
<ref name="Packard Bell XT">Reddit — [http://www.reddit.com/r/MechanicalKeyboards/comments/2frk9q/old_packard_bell_xt_keyboard_that_i_found_in_my/cki1ofx Old Packard Bell XT] Dated April, 2014. Retrieved 2015-07-26.</ref>
<ref name="Chicony KB-5191">Reddit — [https://www.reddit.com/r/MechanicalKeyboards/comments/71n4ur/where_has_this_switch_been_hiding_all_my_life/] Dated September, 2017. Retrieved 2017-09-23.</ref>
<ref name="Sejin_1080">egloos — [http://egloos.zum.com/curio/v/343671 Sejin SKM-1080]</ref>
<ref name="sigma">Imgur — [https://imgur.com/a/OXO5ZjL Sigma APO System AFK-7711 (Futaba MA)] Uploaded 2022-06-09.</ref>
<ref name="olive">Imgur — [https://imgur.com/a/jv0Gyn9 Olivetti M15 Laptop (Futaba MA, Inverse Cross Mount)] Uploaded 2022-12-24.</ref>
</references>

[[Category:Futaba switches]]
[[Category:Metal contact switches]]
[[Category:Clicky switches]]
[[Category:Illuminated switches]]
[[Category:Stacked spring switches]]
[[Category:Keyboard switches with Cherry MX mount]]
[[Category:List of all keyboard switches]]