Alternatives to springs for key switches -- air, gel, etc.

[Proto]

Hello everyone,

To your knowledge, has anyone developed or offered a different kind of key cushioning mechanism? It seems like metal springs have been the only mechanism. What about an air spring system or gel? I saw an old patent for a torsion bar instead of a spring -- that's the only alternative I've seen.

[snacksthecat]

A couple people on reddit have done some experimenting with magnets. I'm not able to fetch the link right now but I'll come back later and post it. You can also find it pretty easily by searching /r/mechanicalkeyboards

[snacksthecat]

A couple people on reddit have done some experimenting with magnets. I'm not able to fetch the link right now but I'll come back later and post it. You can also find it pretty easily by searching /r/mechanicalkeyboards

https://www.reddit.com/r/MechanicalKeyb ... h=4d4c5058

https://www.reddit.com/r/MechanicalKeyb ... h=8aab7ef0

Pretty cool stuff

[Elrick]

A couple people on reddit have done some experimenting with magnets.

Isn't there already a keyboard range out using Magnets within their switch/motherboard?

I think (my thoughts here) the more complicated the switch the more reason it shall fail over time. It's the same with every man-made object that it applies to.

The simplest switch lasts for decades even when external dust and grime afflicts the switch structure, it still works reliably (ie Model-M).

That is why certain keyboards work over great lengths of time, verses others that break down easily within a couple years of usage. If it's electrical/magnetic then most definitely will need complex repair or replacement.

[Blaise170]

There's already a huge number of different switch types, but most aren't manufactured anymore since they are usually cost prohibitive. Notable among these are reed switches, which use magnets (and often springs, but this isn't required). Cherry's original switches used a bar tab instead of a helical spring like most switches today use. It's just the springs are one of the cheapest and most reliable ways of changing the force and "cushion" of the switch.

[rich1051414]

The problem is, magnets degrade when used in 'opposing' orientation, so that isn't a viable replacement for a spring.

[Proto]

A couple people on reddit have done some experimenting with magnets. I'm not able to fetch the link right now but I'll come back later and post it. You can also find it pretty easily by searching /r/mechanicalkeyboards

https://www.reddit.com/r/MechanicalKeyb ... h=4d4c5058

https://www.reddit.com/r/MechanicalKeyb ... h=8aab7ef0

Pretty cool stuff

Interesting! I hadn't thought of magnets at all. It seems like it might be a smoother mechanism.

I had visions in my head of pumping up a keyboard periodically with a sports ball air pump, where the air would be distributed to Nike Air-like compartments under each key... And where you could vary the level of air/resistance at any time to suit your preferences.

[andrewjoy]

We could make a sheet of a soft material shape some dome or cup type shapes on it and use that ?

We could even use it to activate each switch by pressing on some contacts.

This would save massive amounts of money as we could make it in one big sheet

[Dingster]

We could make a sheet of a soft material shape some dome or cup type shapes on it and use that ?

We could even use it to activate each switch by pressing on some contacts.

This would save massive amounts of money as we could make it in one big sheet

Rubber sounds like a good idea!

[Blaise170]

[Dingster]

That was a fast prototype. How does it feel?

[Iggy]

That was a fast prototype. How does it feel?

Squishy and gross, like pressing filled condoms, probably.

[Findecanor]

Just seconds ago, I glanced through a review of the latest Dell XPS 15 laptop. It has maglev switches ... but very low profile. Have been compared to Apple's super-low profile.

This Univac keyboard has magnets in combination with a coiled spring. The magnets hold the keys at the top and the sensing is capacitive.

As to springs, both coiled springs and leaf springs have been used.
And there are keyboards out there that have plastic leaf springs even ... but I think most of these are portable devices with undersized keys.
Check also out the Oki Gourd Spring where the upper half of the spring is pulled when the key is pressed. There is also a tactile variant of it. Pretty cool and simple design.

[webwit]

DataHand magnetic/optical switches.

[Proto]

Hi all -- Thanks for all the info. On the magnetic idea, I just discovered something called a Hall Effect keyboard that has been around a while: https://en.wikipedia.org/wiki/Keyboard_ ... t_keyboard

[Proto]

What is this? How does it work?

[Findecanor]

Hi all -- Thanks for all the info. On the magnetic idea, I just discovered something called a Hall Effect keyboard that has been around a while: https://en.wikipedia.org/wiki/Keyboard_ ... t_keyboard

Hall effect is only a sensing technology however. It does not produce any resistance.

BTW. Hall effect sensors are also used in high-end joysticks, such as those used to control airplanes and heavy industrial equipment.

What is this? How does it work?

You're joking, right?

[Darkshado]

Proto: in case you're not (we all have to start *somewhere* after all), those look like the internals of a Topre capacitive keyboard. I'll let you search from there.

[Proto]

Hi all -- Thanks for all the info. On the magnetic idea, I just discovered something called a Hall Effect keyboard that has been around a while: https://en.wikipedia.org/wiki/Keyboard_ ... t_keyboard

Hall effect is only a sensing technology however. It does not produce any resistance.

BTW. Hall effect sensors are also used in high-end joysticks, such as those used to control airplanes and heavy industrial equipment.

What is this? How does it work?

You're joking, right?

Negative, not joking. I've never done a keyboard teardown. Is this a membrane?

My dream is a passive optical keyboard with the best action possible.

[Blaise170]

Yes it's a rubber dome that I posted. This one happens to be Topre (which people will argue are actually mechanical because of the discrete springs).

[Proto]

Do Apple's problematic super-thin keyboards have springs? (https://www.extremetech.com/computing/2 ... d-analysis)

I think I mistakenly assumed all keys had springs, but Apple's don't look like they have room for springs.

I'm still intrigued by a passive optical keyboard: https://patents.google.com/patent/US4379968A/en

With air or some other cushioning and spring-back mechanism...

[Blaise170]

Apple's switches are basically glorified scissor switches that use a metal tab instead.

[lemur]

wet newspaper

wet newspaper.JPG (167.02 KiB) Viewed 7018 times

[PlacaFromHell]

New airguns usually use nitro pistons instead of springs. They are a lot more consistent, smoother (if they are well lubed) and more durable, considering that those pistons have less vibrations and a more straight upstoke they should be even more lineal than normal springs. You could combine them with a contactless sensing technology to create a "god tier switch", also use the piston housing to hold the entire moving part. The most durable, linear and smooth switch ever built.
Unfortunately I'm too poor and lazy to do that

[Findecanor]

Apple's switches are basically glorified scissor switches that use a metal tab instead.

I think they are metal domes. It is a type of very low-travel switch that used to be more common for pocket calculators back in the 1970s before people decided rubber domes were better.

[Blaise170]

I think they are metal domes. It is a type of very low-travel switch that used to be more common for pocket calculators back in the 1970s before people decided rubber domes were better.

There is a patent that was filed which shows the scissor mechanism. They do have a dome of sorts, but the dome isn't strong enough to return the key to its initial position without the help of the scissor.

[andrewjoy]

They also took a page out of IBMs book and riveted them into the case, the older done switches from the 2015 where screwed in so they where easy to replace ( well in comparison to the new one) you still had to strip the whole machine.

Honestly i think they did this out of spite as they had known since the new macbook a few years ago that the concept was flawed

[Proto]

New airguns usually use nitro pistons instead of springs. They are a lot more consistent, smoother (if they are well lubed) and more durable, considering that those pistons have less vibrations and a more straight upstoke they should be even more lineal than normal springs. You could combine them with a contactless sensing technology to create a "god tier switch", also use the piston housing to hold the entire moving part. The most durable, linear and smooth switch ever built.
Unfortunately I'm too poor and lazy to do that

This is fascinating. How could airguns not use air though? What kind of airguns are these, in terms of scale and application?

[Proto]

New airguns usually use nitro pistons instead of springs. They are a lot more consistent, smoother (if they are well lubed) and more durable, considering that those pistons have less vibrations and a more straight upstoke they should be even more lineal than normal springs. You could combine them with a contactless sensing technology to create a "god tier switch", also use the piston housing to hold the entire moving part. The most durable, linear and smooth switch ever built.
Unfortunately I'm too poor and lazy to do that

This is fascinating. How could airguns not use air though? What kind of airguns are these, in terms of scale and application?

[PlacaFromHell]

This is fascinating. How could airguns not use air though? What kind of airguns are these, in terms of scale and application?

When you "break" the barrel a bunch of air is loaded into a sealed camera near to the piston. Then when you shoot, the brute force of the retracted piston being liberated pushes the air and it shoots. It's much similar to a crossbow.
Most of them are single shot, feather hunting guns. Usually you buy one of these if you can't afford PCP or CO2 rifles (both pre-compressed air mechanisms) or just don't want to worry about an inflator or a C02 supply.
Backing to the crossbow comparison the logic is simple, less friction, more usable strength, like the pulleys of a compound bow. And believe me, turkish airguns manufacturers know about smoothness!