First ever keyboard with Tokai MM9 switches discovered

[subcat]

One of many from my Japan haul. This is, as far as I know, the only full keyboard to date with these switches. They use an alloy metal ball as part of their contact mechanism. wiki/Tokai_MM9_series

Still figuring out how to open them without seriously damaging them.
As usual bear with me while I take photos in weird lighting conditions with a smartphone camera

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Looks like Geekhack have been around longer than we thought! :P

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CLER

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Keycap mount

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One of many from my Japan haul. This is, as far as I know, the only full keyboard to date with these switches. They use an alloy metal ball as part of their contact mechanism. wiki/Tokai_MM9_series

Still figuring out how to open them without seriously damaging them.

[Chyros]

Super awesome! I have a few of these switches and even after opening I still haven't got a clue as to how they work. They're the weirdest switch design I've seen so far xD . Really cool to finally see a keyboard of them!

How do they feel? xD

[subcat]

Super awesome! I have a few of these switches and even after opening I still haven't got a clue as to how they work. They're the weirdest switch design I've seen so far xD . Really cool to finally see a keyboard of them!

How do they feel? xD

They are a novel switch design indeed! The travel is quite short and they have a moderate tactile bump (of course, you know this already ) What's interesting to me is that if you press the switch really slowly, the tactile bump has like... lots of smaller tactile bumps? I don't really know what the best way to describe it is, but you know how when you zip up a zipper or something you get that continuous bumpy feedback? ...kinda like that, I guess.

[paecific.jr]

Wierd, whats the weight like on them?

[subcat]

Wierd, whats the weight like on them?

I could try doing a makeshift ripometer with Australian 5 cent pieces :p
Edit: done, it appears to be 50-55g - take that with a damn good helping of salt though, my testing methods were pretty janky.

[Findecanor]

have a few of these switches and even after opening I still haven't got a clue as to how they work.

Hmm.. My guess from looking at the images in the Wiki is that actuation is reversed, I.e. the switch is closed when the slider is up. When the slider is pressed down, a protrusion inside the slider pushes the ball away from one pair of contacts.

Edit: MouseFan's page says that the actuation is not reversed..

[seebart]

Very nice find subcat! Your pictures are fine, thanks for sharing.

[emdude]

Very interesting, I recall seeing this keyboard when you posted live pictures on Telegram.

Haata also has a keyboard with Tokai MM9 switches, though his possibly uses a different variant. Intriguing that his keyboard appears to use the same sort of relegendable keycaps:

https://www.flickr.com/photos/triplehaa ... 743289012/

[Chyros]

Super awesome! I have a few of these switches and even after opening I still haven't got a clue as to how they work. They're the weirdest switch design I've seen so far xD . Really cool to finally see a keyboard of them!

How do they feel? xD

They are a novel switch design indeed! The travel is quite short and they have a moderate tactile bump (of course, you know this already ) What's interesting to me is that if you press the switch really slowly, the tactile bump has like... lots of smaller tactile bumps? I don't really know what the best way to describe it is, but you know how when you zip up a zipper or something you get that continuous bumpy feedback? ...kinda like that, I guess.

Well I have a few loose switches but that really isn't an indication of what they feel like in the flesh, hence why I was curious . Sounds like a weird keyfeel xD .

have a few of these switches and even after opening I still haven't got a clue as to how they work.

Hmm.. My guess from looking at the images in the Wiki is that actuation is reversed, I.e. the switch is closed when the slider is up. When the slider is pressed down, a protrusion inside the slider pushes the ball away from one pair of contacts.

Edit: MouseFan's page says that the actuation is not reversed..

Yes, they are definitely a sense-high design, I measured it with my multimeter a while ago. That said, I sacrificed one of the normal switches and one of the clone switches, which appear to be identical inside, but they feel and sound completely different. Moreover, I genuinely have no idea how the hell they work, or why they are so different while looking the same. I've seen some seriously weird switch designs in my time but this is way more of an enigma to me than Hall effect or magnetic valve xD .

By the way, they're also a very short-lived switch; as I recall, they were specified to have a lifetime of just 1 million operations xD .

[Daniel Beardsmore]

Those will be MM9-1 (tall keystem). The force curve is odd:

https://plot.ly/~haata/166

It suggests that you instantaneously reach the tactile point, which seems very odd, as you don't. It feels as weird as the graph suggests, but not specifically what the graph suggests.

The reason behind the design is to avoid contact wear: the ball rotates, presenting a fresh surface to the contacts with each stroke. That is according to Tokai's website; at some point I'll record the details on the wiki — I found them while digging up information on their optical switch. A 1 M lifetime seems very odd, and I have to doubt it — nobody would make anything this bizarre when a cheap and nasty switch lasts longer.

The exact operation remains a mystery. The spring sits above the ball and below the slider, so it pushes the slider up while pushing down on the ball, yet somehow still lifts the ball clear of the contacts. Sadly the design doesn't permit testing it; you'd need a 3D printed clear plastic replacement shell (if that's possible) to see the parts in motion.

Thomas has clones — there are at least two physically different clones. One type is "G" branded and the other type is not branded at all.

[Daniel Beardsmore]

耐久性能 2,000,000回 （負荷DC20V, 1mA）
・接触抵抗 ： 3Ω以下。
・バウンス　： ON 5mSec以下、OFF 10mSec以下

2 million, with 5 ms make bounce and 10 ms break bounce.

Wow. What on earth were they thinking?

Google's being frivolous today, too:

2億 = 200 million
2億回 = 200 million times
億回 = Million times
億 = Billion

Not sure how that works. 億 is one hundred million.

[subcat]

Could well be that some of these are all used up, if that's the case.

[Daniel Beardsmore]

You could buy MM9 directly from the Tokai website. In both 2007 and 2016, the prices were as follows:

MM9-1 20個パック ￥1,500.-(￥1,575.-)
MM9-2 20個パック ￥1,400.-(￥1,470.-)
MM9-3 10個パック ￥1,100.-(￥1,155.-)
MM9-4 10個パック ￥1,300.-(￥1,365.-)

Google figures 20個パック is "20 packs", but I assume at that price it's going to be a pack of 20. Currently that's US$13.30 for MM9-1, or 67¢ each. (They didn't ship outside of Japan or accept VISA, otherwise I'd have bought some.)

What I really wanted was to compare the price with SPT-0101, their optical switch. Sadly that was never available for sale from their website, so I have no idea about the pricing.

By comparison, a RAFI RS 74 M switch (3.13.002.502/0000), MOQ 25, was €1.33 from a particular distributor in 2016 (currently US$1.43). If you bought 3000 of them, you'd pay €1.24 each. Those have five times the lifetime at 10 M.

Mechanical Keyboards price for 10 Cherry MX Black (50 M lifetime!) is US$10, so $1 each. For 10+ packs, they're $5 each, or 50¢ per switch. For 3000 (as with the RAFI pricing I was given) that's $300, vs $4000 for the same number of RAFI switches.

It does seem that these Tokai switches were cheap, but Cherry is so much better value for money.

I have both MM9-3 and MM9-4 to hand (the non-keyboard types) and I'm coming to understand these better.

MM9 is progressive rate with knee. This is how I perceive it:

Perceived force curve of Tokai MM9

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In reality there's a force wall to catch you, that you saw in Jacob's graph. It's curious that I mentioned RAFI, as RAFI make the only other known progressive rate with knee design, RS 74 M illuminated; that doubles the bounce time to 10 ms, but still offers 10 M lifetime.

I also have two MM9-2 clones. One may be Kwanda; I can't tell. That one feels more like a stiff Cherry MX Brown: linear with a bump. There's no sense of progressive rate with that type. The "G" type however is very different:

Perceived force curve of "G" vs MM9

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There's a huge wall to overcome first.

So, Tokai's advantage is having progressive rate. MM9 feels so much better than the clones: lighter and smoother.

[Daniel Beardsmore]

BTW, as for the keytops:

「キートップはTOBシリーズ(1倍：TOB-S1B、2倍：TOB-W1B)とクリアカバー付きのMTBシリーズ（1倍：MTB-S1B、2倍：MTB-W1B）を用意しています。」

It appears that TOB series is just the bases, and MTB series has the clear covers.

http://web.archive.org/web/200710110414 ... detail.htm?

[subcat]

Great info! "Actuating force: 100 ± 30 g" is very interesting to me, that's quite a wide parameter
They really have some info there, I never considered a switch's operating temperature before.

[Daniel Beardsmore]

Their specs are fairly normal actually — any good manufacturer will provide at least that much detail.

[DeChief]

You could buy MM9 directly from the Tokai website. In both 2007 and 2016, the prices were as follows:

MM9-1 20個パック ￥1,500.-(￥1,575.-)
MM9-2 20個パック ￥1,400.-(￥1,470.-)
MM9-3 10個パック ￥1,100.-(￥1,155.-)
MM9-4 10個パック ￥1,300.-(￥1,365.-)

Google figures 20個パック is "20 packs", but I assume at that price it's going to be a pack of 20. Currently that's US$13.30 for MM9-1, or 67¢ each. (They didn't ship outside of Japan or accept VISA, otherwise I'd have bought some.)

Yes, you're right; that does indeed say "a pack of 20" (more or less). If I'd been browsing this forum earlier, I could've bought some and shipped them for you.

[tronic307]

This is the primary switch type used in Japanese arcade buttons. Sanwa uses snap-together clones of this switch with linear feel, while Seimitsu uses the original riveted tactile TKC MM9.
https://www.akishop.jp/button-parts/149-sw-68.html##
https://www.arcadeworlduk.com/products/ ... inals.html
https://www.arcadeworlduk.com/products/ ... witch.html
https://www.akishop.jp/button-parts/151 ... witch.html##
https://www.akishop.jp/button-parts/152 ... witch.html##

Another button from HORI that uses clones of this switch type:
https://www.arcadeworlduk.com/products/ ... utton.html

A bit off-topic, but here is a mod that allows for the installation of MX switches in Sanwa arcade buttons:
https://paradisearcadeshop.com/755-obs-mx-button-system

S̶e̶i̶m̶i̶t̶s̶u̶ ̶J̶B̶-̶3̶5̶-̶T̶ ̶A̶r̶c̶a̶d̶e̶ ̶B̶u̶t̶t̶o̶n̶ ̶s̶e̶e̶m̶s̶ ̶t̶o̶ ̶b̶e̶ ̶a̶ ̶g̶o̶o̶d̶ ̶s̶o̶u̶r̶c̶e̶ ̶f̶o̶r̶ ̶s̶o̶l̶d̶e̶r̶-̶l̶u̶g̶ ̶T̶K̶C̶ ̶M̶M̶9̶-̶2̶ ̶s̶w̶i̶t̶c̶h̶e̶s̶.̶
Edit: Seems only JB-35 buttons with 2.8mm terminal MM9-3 switches are available at the link now.

[Daniel Beardsmore]

How did you know that this is TK-80? Is there any way that we could see (and preserve) or reference that fact? (Since we have no other model information and Tokai are no longer around to ask.)

[tronic307]

How did you know that this is TK-80? Is there any way that we could see (and preserve) or reference that fact? (Since we have no other model information and Tokai are no longer around to ask.)

I have a few MM9-3 with the diamond TKC logo from old Seimitsu arcade buttons. That and the rivets visually distinguish them from clones. The MM9-1 seems to be the only true rarity.

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On the Seimitsu website, directly referred to as MM 9-2, MM 9-3 and MM 9-4 respectively:

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http://www.seimitsu.co.jp/botan.html#麻雀

Teardown pics here with comments (Japanese):
http://www5f.biglobe.ne.jp/~silencium/k ... /hori.html

Lots more info here including keycaps and mechanical drawings. Looks like there's an order form too.
https://www.jw-shop.com/P-keyboard-mswi ... detail.htm

[Daniel Beardsmore]

I have a few MM9-3 with the diamond TKC logo from old Seimitsu arcade buttons. That and the rivets visually distinguish them from clones.

The clones I have of MM9-2 have the same "rivets", although they may not be identical.

On the Seimitsu website, directly referred to as MM 9-2, MM 9-3 and MM 9-4 respectively …

The one thing that their site does indicate is that MM9-4 can take up to two LEDs. However, according to the MM9-4 drawing this does not seem to be possible. The website's tiny image doesn't offer enough clues.

Teardown pics here with comments (Japanese):
http://www5f.biglobe.ne.jp/~silencium/k ... /hori.html

That's where we need a willing translator. Having called for people to translate things from Chinese, Japanese etc for years without success, I doubt that will change now. I do see that he mentions the Tokai optical switch, but even as a Japanese speaker, there's less information on his page than there is on the wiki.

Lots more info here including keycaps and mechanical drawings. Looks like there's an order form too.
https://www.jw-shop.com/P-keyboard-mswi ... detail.htm

The keycap families and the switch drawings (MM9-1 to 4) are all on the wiki already.