Switches: Advertised Lifespan vs. Real Life - SOLVED

[paperWasp]

[problem solved - see the end...]

My Cherry G80-3000 S TKL keyboard with brown switches has been used (quite intensely) for about 4 years. Recently I've noticed that right ANSI Shift has more pronounced tactile bump (feels like 3 times more compared to other keys). Only occasionally, probably when pressed under a specific angle. Mildly annoying.

My another TKL used at work with Kailh Brown switches (about 3 1/2 years in use) is worse. B key does not snap too often, causing typos. Again maybe just a specific angle/speed/whatever but definitely fully pressed down and no output.

The Cherry switches should withstand 50 mil. to 100 mil. presses but according to my calculation, even the most used keys must be under 2 million.
The most used Kailh switches most probably under million 1 (should last 50 million).

So is that advertised lifetime just a marketing BS?

[xxhellfirexx]

The lifetime count is the average number of presses until the keyswitch no longer actuates. Even if the keyfeel is scratchy, loses the click, or loses the tactile feel.

[paperWasp]

So the usable life can be just a fraction of the advertised life (the number on the box)...

That Cherry is still fine - the randomly tougher right shift (at the moment it looks cured ???) isn't a big problem a and the typing experience is still very good.

On the other hand, the unreliable 'B' on the keyboard with Kailh switches makes me want to replace the board. You don't buy a mechanical keyboard for the clacky sound while typing, do you? You want a typing experience better than with rubber domes.

[vvp]

I have some Gateron switches a keyboard of mine. I needed to replace 3 switches on it. The approximate number of presses on each replaced switch was around 3 mil. The other switches on the keyboard are still ok.

[paperWasp]

I have no experience with Gaterons but even they should also last more that that:

Gateron switches are built to withstand a high number of key presses. The keystroke lifespan for each switch is typically rated for tens of millions of keystrokes. This durability ensures that the switches remain responsive and reliable throughout their lifespan.

When I was young, I used to have at least below the average amateur soldering skill (D-sub 15 pin successfully re-soldered has probably been my best work ever) but I've lost them all with the age. I would have to ask someone to do the replacement for me. Then probably another switch and so on.

I wonder if the old switches (not the modern ones, made in China) used to last longer? I don't mean a keyboard conserved for three decades in a box, but a keyboard actively used for typing with tens of millions actuations?

[vvp]

Well, if helps you then here is another data point.
Kinesis Advantage, Cherry MX Brown, produced & bought in 2002 in USA. I do not know where the switches were produced. Two switches turned bad in around 2014. Estimated number of presses on them was about 6 million.

I do not have more experience with original Cherry MX. Anyway my experience with Gateron is very similar to the experience of my brother with Gateron. He had some switch failures as well. It is not a big deal for me. I have Gaterons in a custom built keyboard (K84CS) and I can replace a switch in about 20 minutes.

[tron]

I've noticed the updated "V2" or recent Kailh box switches are now claiming 70 to 80 million. It's safe to assume most switch brands have updated their QC since ~2018 and the new molds, upgraded materials and lube could help reduce wear and extend life. Also, consider the environment the switches will be in, if you're just using the board in a house or office space, the soft dust shouldn't cause much wear, it's the gritty industrial dust in factory environments that causes issues in the long run. I always buy ~10 to 20 extra switches, rotate in different boards and cover the board when not in use so I've never had a switch go bad on me since joining this hobby over ten years ago.

[AndyJ]

I've used the same IBM Model F keyboard for forty years. Despite discrete mechanical bits flapping around under the keycaps, it still works just fine.

[paperWasp]

I've created a Python program (OK, ChatGPT has created it for me) that counts keypresses from all running applications. Space bar is the most used key (as expected) but it looks like even my estimates from the original post have been probably too much.
The right shift on my Cherry G80-3000 S TKL seems still fine - maybe it just was some dirt, causing mild problems for a couple of days. But the problem with unreliable B key (Kailh switch) persists.

Six millions isn't a bad number but still far from 50 millions to 100 millions. I don't trust those Kailh claims anymore. I was pretty naive to believe those numbers. If this isn't just a marketing number based on marketing numbers from similar products, the laboratory testing "press" won't probably do all those out-of-the-keycap-centre pushes, finger pivots and wobbling, too strong presses etc. but actuate the switch in a very standard and moderate way.
That Model F used for forty years is a good point, but it's a different tech. Not sure about new Model F keyboards.

I do like mechanical keyboards and will probably buy another one again but a cheap Microsoft where I completely brushed off F J homing bars and was still performing in an acceptable way or an old Logitech from my wife who is a linguist and types a lot make me wonder if rubber domes don't last longer than those much more expensive switches.

[vvp]

It is probably switches with some kind of defect which go wrong. E.g. one of the letters which failed for me was C. It is used less than the average. I think E and T were OK too. I'm sure space bar was OK.

[xxhellfirexx]

Six millions isn't a bad number but still far from 50 millions to 100 millions. I don't trust those Kailh claims anymore.

I do like mechanical keyboards and will probably buy another one again but a cheap Microsoft where I completely brushed off F J homing bars and was still performing in an acceptable way or an old Logitech from my wife who is a linguist and types a lot make me wonder if rubber domes don't last longer than those much more expensive switches.

To further inflate numbers, some switch manufacturers list switch mechanical lifetime and electrical lifetime.
https://metrol-sensor.com/solution/87732/

Devices that have less moving parts are known to last longer before mechanical failure.
https://revpart.com/living-hinge-design-guide/

[paperWasp]

Interesting! Thanks for those links.

That living hinges durability might probably also explain why good rubber domes can sometimes last for so long - i.e. many years of intense use.

I just wonder if materials used in modern products (of course not only keyboards) are still good enough. I mean repeated recycling, cutting costs by cheaper additives etc. You will probably have about the same typing experience with a New Model F keyboard but will it last four decades of use like its original?

[paperWasp]

Now I feel like a total idiot.
I've just brought the keyboard with Kailh switches from work, tried it with my home Linux computer and it looks like there is no randomly not actuating B problem!
After typing single B sequences, I retyped two full pages of text (I'm a quite fast touch typist) - just not to focus on the B key - and haven't noticed a single missing B either.

So it must be a weird problem in unreliable "pairing" with my Dell laptop running Windows. The keyboard is USB one, not Bluetooth. Strangely the laptop works fine with another keyboard (a basic old rubber dome without backlighting etc.) Anyway, I'm not buying a new keyboard at the moment, maybe I'll try swapping the board with Kailh switches with my home Cherry keyboard.

[xxhellfirexx]

I just wonder if materials used in modern products (of course not only keyboards) are still good enough.

Rubber domes in the early 2000s and now are still using pretty much the same materials. The design is already so optimized there is not much more that can be taken out.

I mean repeated recycling, cutting costs by cheaper additives etc.

Most plastic is only partially recycled. Manufacturers can further cut costs by only offering low profile keyboards that is shared with laptop keyboards.

You will probably have about the same typing experience with a New Model F keyboard but will it last four decades of use like its original?

It depends on the environment it is used in (salty, humid, sooty, oily environment) and if it gets regular maintenance (foam mod, reseat springs).

[vvp]

I can confirm that oily environment is bad for rubber domes on TV remotes at least. If it gets there then not only it degrades the contact conductivity but may also soak into the conductive rubber and damage its conductive properties.
This should not be such a big problem for PC rubber dome keyboards. The rubber there is not conductive and not that important. The conductive contact is between the two membranes. If oil gets there then they will stop to work well too.