Lubed Mitsumi MM Review

[Thorogrimm]

After my last review of the Silitek dome with slider keyboard, a kind fellow from Germany (you may know him as Keybug) reached out to me to review a keyboard he appraised for having an overlooked typing feel once lubed. That being the tactile Mitsumi Miniature Mechanical switch or MMM switch. Keybug mentioned that he'd spray lubed these switches which gave them an unprecedented smooth and sharp tactility that I may enjoy very much. So I took him up on his offer and here we are!

I was in fact sent two boards with these switches (both by the same brand) being Chicony. One KB-5191

with entirely tactile green MX mount MMM switches (paired with abs dye sumblimed caps inc. red German legends). And one KB-5192

with both white linear Alps mount and yellow tactile MX mount, which I found very bizarre because they also used only the linears for the alphabetical legends (paired with abs doubleshot keycaps), and tactile for all the other keys (having abs screen printed caps with uv coating).

The keycaps on both these keyboards are pretty thin but the ones on the primarily tactile board are much nicer and consistent with a smooth satin-like feel. But for some reason the E, R and T keycaps on the 5191 kept coming loose and popping off during typing. This might have been due to the lubing process, so I solved this by cramming a tiny square cut from a dry anti-bac wipe into the keycap, which held it on just fine afterwards.

Onto the build quality of these boards, they're not amazing by any stretch; they both flex a lot and feel very cheaply made and they're very light--likely for lack of any metal backplate. However, the KB-5192 seems much worse, either because of how it's been treated over years of use or because the manufacturing got even cheaper. In any case, it's got weirdly mis-alligned switches

and the screws which hold the lower corners of the keyboard together have broken away from the case

Already these keyboards are seeming like a mixed bag. The flip-out feet appear to be pretty bog standard and creak like a motherfuck so I had to lube them to try and help them flip out a little smoother. Both these keyboards have coiled 5-pin DIN cables that are a little bit loose in their case, as when I recieved them, the KB-5192's cable was moving uncomfortably freely in it's socket. So I had to open it up and make sure it was securely crammed between some standoffs.

Now you're probably thinking "these keyboards sound pretty bad, can the switches redeem them?" Well I'm sure that's what you're all here for. And I will answer that in a 𝙡𝙤𝙣𝙜 𝙖𝙣𝙙 𝙘𝙤𝙣𝙫𝙤𝙡𝙪𝙩𝙚𝙙 𝙛𝙖𝙨𝙝𝙞𝙤𝙣.
Just kidding...
The tactile switches are the reason why Keybug sent me these keyboards, and I mentioned earlier that what improved them was the lube spray he had applied to them. And, I must say... these are in fact probably one of, if not, the most tactile switches I've used. They're incredibly snappy and (after just coming from BTC dome w/ sliders) you have literally no choice but to bottom out. They produce a very thocky sound and are pretty smooth as tactile switches go. As a fan of tactile switches I enjoyed these a lot! I could even compare them to my click-modded Dell AT102W and BTC 5140.

The linear switches on the other hand are a bit on the scratchy side and produce a pinging noise. But otherwise, not the worst switch I've used and they're at least responsive and come with doubleshots.

See the typing demosntrations below.
https://imgur.com/a/hz6dq18

Overall, the MMM tactile switches are definitely something everyone (especially those who enjoy tactile switches) should try if they can get their hands on a board with them! However, if possible, look towards another brand as you're not getting amazing quality with the Chicony models.

I will be selling the Chicony KB-5192 (with the linears + tactiles) to whoever wants to own it. So just send me a PM with an offer!

[Jan Pospisil]

Hah, I have the exact same Chicony with Czech legends, NOS.
So the lubing does improve the off-center binding?

[Thorogrimm]

Hah, I have the exact same Chicony with Czech legends, NOS.
So the lubing does improve the off-center binding?

It does, I haven't noticed much, if any binding

[TNT]

Wow, that sounds great! I have a Unitek K151N with yellow MMM, which is dreadful to use due to the binding and so on. I was discouraged to try to improve them due to Chyros' reviews of the switches, but I'm eager to try this out now, since I like the chassis so much. What lube did Keybug use and how exactly did he apply it? I can probably get the exact same one, since I live in Germany too.

[Thorogrimm]

Wow, that sounds great! I have a Unitek K151N with yellow MMM, which is dreadful to use due to the binding and so on. I was discouraged to try to improve them due to Chyros' reviews of the switches, but I'm eager to try this out now, since I like the chassis so much. What lube did Keybug use and how exactly did he apply it? I can probably get the exact same one, since I live in Germany too.

This is what he wrote.

[TNT]

Haha, alright. Thanks for the info!

[Thorogrimm]

Haha, alright. Thanks for the info!

Careful with the caps, though. I mentioned in the review that the lubricant may have caused some of the caps to slide off. So I had to remedy that.

[TNT]

Yeah, I'll make sure to keep those as dry as possible. My caps don't seem to be loose or even just kinda loose to begin with tho, so I'll see whether that is going to be an issue or not

[Rayndalf]

This is what he wrote.

I did basically the exactly same thing recently. Except it was the WD40 silicone based lube. I probably put it on a little tii much but at least the ones that had started making noise stopped. They definitely bind less but I can say much else, I ruined the keyset trying to whiten it (I have a spare set though)

[TNT]

Ok, my room smells like WD40 now, but you were right, it's a massive improvement. Some of them are still kinda bindy on the very offcenter presses, but the rest of em work great. Makes me wonder what the optimal lube to use on them would be.

[Thorogrimm]

Ok, my room smells like WD40 now, but you were right, it's a massive improvement. Some of them are still kinda bindy on the very offcenter presses, but the rest of em work great. Makes me wonder what the optimal lube to use on them would be.

I hear that SuperLube spray is a good option for spraying switches.

[headphone_jack]

Very interesting. I was under the impression that MMM were super hard to disassemble in a non-destructive manner. How is it done? I was also doing a little investigating of my own on why exactly they bind so much. I have a loose Mitsumi Standard switch that I got from a lot on Taobao. My theory is that there is a small discrepancy between the width of the plate cutout and the width of the switch housing, causing the rails to compress against the slider. Even just squeezing my fingers together on either side of the housing caused a significant decrease in smoothness. I was considering trying to make a plateless MMM custom, to see if this solves the issue, but that is a long way in the future.

[TNT]

That's an interesting theory. However, my board is plateless and it still has (or now had) severe binding issues.
I have not disassembled a switch yet, but I'm willing to try.

I hear that SuperLube spray is a good option for spraying switches.

Interesting. What product of theirs are you exactly referring to? The wet PTFE, or the silicon based one? Also, I'd have to clean out my now WD40'd switches first, right?

[Keybug]

I think what happens is that the metal of the top housing (silly choice of material!) corrodes and thus become rough and / or interacts with the plastic of the slider hence I considered WD-40 to be ideally suited as:

WD-40 isn't actually a true lubricant. WD stands for "water displacing" and its main use is as a solvent or rust dissolver. The lubricant-like properties of WD-40 come not from the substance itself, but from dissolving components. And the effect doesn't last.
WD-40 can be a good substance to start with — it can help clean up rust or other grime. But depending on what you're working with, you should probably follow up WD-40 with use of a true lubricant such as one based on silicone, grease, Teflon, or graphite.

So far, I have only ever applied WD-40 to my MMMs, just spraying into and onto the switch from the top (I know...). Maybe if one went the extra mile and introduced some proper lubricant, the vestiges of binding might disappear.

I find mine to be extremely snappy tactiles now and really like their thocky sound. I have begun to wonder whether they might have slightly progressive springs in them, at least the linears, as I can type faster on them than on pretty much anything else and they do feel somewhat bouncy to me. By the way, those linears were desoldered from two numpads that came with them and then substitued into the board that came with yellow tactiles (my least favourite breed) I gave to Thorogrimm. The misalignment of the keys is simply due to shaggy soldering.

I have two Chicony 5160s with them - and the experience is much nicer in those sturdier boards. My 5160 with white tactile MMMs is one of my favourite vintage boards with regard to typing feel.

Anyway, I really do hope more people are going to look into them now thanks to Thorogrimm's effort - there is a lot to like here for tactile afficionados.

[TNT]

Just ordered some WD40 branded silicon lube. Not really a tactile guy tbh, but I really like those Mitsumis and wanna try this out. What's the difference between the yellows and the whites? How does the clicky version feel like?

[Thorogrimm]

Just ordered some WD40 branded silicon lube. Not really a tactile guy tbh, but I really like those Mitsumis and wanna try this out. What's the difference between the yellows and the whites? How does the clicky version feel like?

The yellows are the tactile and the whites are linear. I've never tried the orange clicky versions though.

[TNT]

Hmm, but the Wiki (and Keybug) mention(ed) white tactile switches, so I was wondering in what way the white tactile ones are superior to the yellows. I just realized btw that my board got a linear version of MMM for the spacebar switch that is not listed on the wiki. Do the colors even mean anything besides probably production date?

[Keybug]

The board that Thorogrimm is now selling has white Alps-mount linears on the alphas that I took from two numpads.

All the examples I've seen in full keyboards were tactile: yellow, green and white. The difference between them is not terribly significant, probably just the weighting and possibly the more or less progressive quality of the spring (if my gut feeling is correct).

[TNT]

Lube arrived, will try today.

[Bjerrk]

Lube arrived, will try today.

Fingers crossed! Looking forward to the results!

And also very interesting in hearing how they fare after a while. The WD40 magic could easily wear off

[TNT]

I already realized a difference just two days after I applied WD40, for the better in this case. My guess is a lot of the excess stuff evaporated, leaving only the oily components behind. That would explain why it smelled noticeably less intense and the key feel was different, more "even" if that makes sense.

[TNT]

Ok, I'm going to be honest: I don't feel that much of a difference. They're maybe a tad bid smoother, but that's it. I'd still advice for it because of the longevity issue with normal WD40.

Furthermore, after trying out the board for a longer time I think they're not really for me. Mostly because I like linears and light clickys more and they're a tad bit too stiff for my liking. But I guess that's only an issue if you're typing like me: I tend to have my hands really flat on the board and don't strike the keys directly "angular" from above. Rather with very little force and flat fingers, if that makes any sense. Therefore, the little binding that is left on mine is still noticable for me.

But still, lubing them makes a whole lot of a difference and my board only has yellow Mitsumis. I urge everyone who has one neglected Mitsumi-Board to try this out.