Found keyboard with White Mitsumi Mini Mechanical (Cherry MX mount)

Cavemanthe0ne · 27 Oct 2017, 05:16

Not entirely sure where to post this but thought this was fairly close for adding to wiki possibly?
Some pics:

It's a Unitek K151L.

Daniel Beardsmore · 27 Oct 2017, 09:29

That is indeed the only type on the wiki without a photo. I don't recall if there are any other types that are missing from the wiki entirely. This is a tactile switch, right? White is less common than yellow but we see it from time to time, and I don't know how it differs from yellow.

Cavemanthe0ne · 28 Oct 2017, 01:10

Its tactile, rather odd tactility however. The bump is at the very beginning of the switch actuation so is... Interesting. Can almost be mistaken for linear switches.
The keyboard itself is rather well made, seems to be a lot better than the yellow mini mitsumi keyboard that Chyrosan did a review on from what I can tell by typing on it. Pretty good build and keycaps, decent otherwise. Not very smooth though compared to alps or cherry blacks.

Daniel Beardsmore · 28 Oct 2017, 12:48

If you want the same kind of feeling but without all the scratchiness, you want a keyboard with [wiki]ITT ETL18[/wiki] switches, which is unfortunate as only one has ever been found!

The problem with those little Mitsumis seems to be off-angle binding, similar to Cherry ML — I'm guessing it's due to how little of the slider is supported by its guide shaft.

Cavemanthe0ne · 28 Oct 2017, 21:40

The only real issues ive noticed is that the "D" and "Caps Lock" keys seem to magically press themselves randomly. Seems to be a short or something. Will have to take the board apart to see what's up. Other than that they are pretty nice switches and everything.
Definitely and interesting add to my collection though lol... My other project atm is converting my AEK II with white damped alps to something useful instead of ADB. Ordered an adapter from one of the guys on geekhack, will see how that goes.

Daniel Beardsmore · 29 Oct 2017, 01:11

It certainly wants to be a good switch. Maybe I'll get to try them out before I die, as well as Futaba MA series.

Cavemanthe0ne · 01 Nov 2017, 08:09

More pics for those interested.
https://imgur.com/a/ynDDF

Daniel Beardsmore · 01 Nov 2017, 09:45

Yellow switches for caps lock and tab — are those likely to be the result of repairs, or does it appear to have been made that way?

From the spring on the space bar switch it seems like Mitsumi didn't offer a heavier weight switch, but then I have to wonder just what is the difference between white, yellow and green anyway? Very roughly, how heavy are these switches? I got approximately 65–75 g for yellow.

Cavemanthe0ne · 01 Nov 2017, 20:14

Daniel Beardsmore wrote: Yellow switches for caps lock and tab — are those likely to be the result of repairs, or does it appear to have been made that way?

From the spring on the space bar switch it seems like Mitsumi didn't offer a heavier weight switch, but then I have to wonder just what is the difference between white, yellow and green anyway? Very roughly, how heavy are these switches? I got approximately 65–75 g for yellow.

It appears that the switches were on there stock, though I have no idea why. There doesnt seem to be a lot of difference between the two switches other than that the yellow switches are less tactile.
Switches aren't smooth compared to MX blacks but they aren't that bad either. Not too sure what to compare them to lol. Still a better tactility than MX brown, if less smooth (but maybe thats because I dont like MX browns much)

Have no idea on the weighting, it's definitely more than 55g and seems to be less than 65g for the tactile whites.
The yellows are a few grams heavier though its hard to tell for both because of the odd switch design.
Space bar is a bit heavier, sounds like a mix of an MX stabilized space bar and a spring design one (because the spring). Massive 10u size is interesting.

Daniel Beardsmore · 02 Nov 2017, 01:20

Even simple coin stacking would give a very rough idea of weight. Curious that white is more tactile … yellow is one of those strange switches whose tactility apparently evaporates when you type on it, something that force curve analysis may explain.

They are indeed scratchy, presumably from how the spring wraps around a post inside as the switch is pressed.

Cavemanthe0ne · 02 Nov 2017, 04:47

Thats what I did and the coin stacking which usually works fairly well for MX and alps, is hit or miss with these because of the odd tactility means i couldn't really tell where the weighting was for sure. Definitely is somewhere in the 55-70g range.
Yellows are a bit different but similar weighting. Main difference is in the level of tactility between the yellow ( less) and white switches (more tactile) so the similar weight makes some sense.

I will say that in the case it's in the switches sound very nice. Might do a video on it lol. But this also reminds me, the PCB is *insanely* thin, I think I know why keyboards that are in plain plastic cases with these sound and feel so crap. The PCB is by far the thinnest and flimsiest I have ever seen.... the metal case makes up for it a fair bit in this keyboard.

I wonder if I can pull these from this PCB and mount them into a 60% or 75% layout PCB thats a lot better and see what that does for the sound & feel of the switches. Have no idea if any new PCBs will work though.

Daniel Beardsmore · 02 Nov 2017, 09:26

These need six holes in the PCB, so the PCB has to be fully custom.

I assume one day we'll see force graphs for some of these Mitsumi types and then we may start to understand what's going on.

Rayndalf · 03 Mar 2021, 07:12

Not sure if this is still relevant, but I found one with green/blue Mitsumi switches as well.

My XT only model has MX blacks but AT/XT models have been seen with MX blacks or Mitsumi switches (my guess is like many Tawainese OEMs they used what ever they could find).

If the wiki still needs some better photos I have 2 (and a third is just a chassis someone else harvested) K151L boards.