Is the form factor of mouse switches standard?

[sudothelinuxwizard]

Forgive me if I'm being stupid here.

Recently, I've been having fancies about replacing the shitty unbranded switches in my Logitech M90 mouse with optical ones. I don't mind soldering or any of the other hassles, but I can not for the life of me find out WHAT format of switch will be able to be soldered into the pads. If it's helpful, the switch has 2 leads, is through-hole soldered, and measures about 14 x 5 x 6.5 mm and the leads are spaced about 6 mm apart (account for +/- 0.5 mm in my measurements because my hands tremble and I couldn't hold the ruler steadily).

 

[Bill_Bright]

Form factor? Not sure what you mean by that. The way the information a mouse sends to the computer is standard. That is, the protocols and voltages used are standardized. But the manufacturers can use any size or shape switch they want - as long as it is a "momentary" switch. That is, the switch completes the circuit when pressed, and stays that way until you lift your finger, then the circuit opens until you press the button again.

 

[sudothelinuxwizard]

Form factor? Not sure what you mean by that. The way the information a mouse sends to the computer is standard. That is, the protocols and voltages used are standardized. But the manufacturers can use any size or shape switch they want - as long as it is a "momentary" switch. That is, the switch completes the circuit when pressed, and stays that way until you lift your finger, then the circuit opens until you press the button again.

I meant the size of the switch and the spacing and size of the leads

 

[Frick]

They use switches, any switches, and those come in a ton of different dimensions and specifications. Whether or not there are optical switches you can just replace them with ... I don't know. I'm thinking probably not, because they work completely differently compared to normal mechanical switches. Normal switches just connects two poles and thus completes a circuit, an optical switch has lights and shutter mechanisms and stuff, meaning the entire mouse has to be designed with that in mind.

And this is just a question: How good are you at soldering, considering your hands shake so much you can't hold a ruler steady?

 

[Bill_Bright]

I meant the size of the switch and the spacing and size of the leads

No standards for any of that.

 

[eidairaman1]

They are proprietary so you should identify your current 1s and take measurements and also ask the manufacture of the device

 

[Frick]

They are proprietary so you should identify your current 1s and take measurements and also ask the manufacture of the device

Not in the case of the mouses I've opened. Those have all either been those push button switches or micro switches. OP wants to replace them with optical switches though.

No standards for any of that.

This is a detour, but I thought stuff like in the attached image were manufactured to some kind of IPC standards or something, like lead/hole size and stuff. Or is it just common sizes they use because everyone else use it?

 

[sudothelinuxwizard]

So you guys mean I'm just supposed to YOLO it and try multiple ones till one fits?

And this is just a question: How good are you at soldering, considering your hands shake so much you can't hold a ruler steady?

Jeez that's brutal... I'd say for the through hole things I've soldered so far I have never broken anything. My joints are never particularly clean but they're also never dangerous or unreliable.

Also, I thought the optical switches were an enclosed unit like the mechanical switches just with a different internal design.

So what kind of mechanical switch should I buy (it appears to be 3.3V)?

 

[BlaezaLite]

So you guys mean I'm just supposed to YOLO it and try multiple ones till one fits?


Jeez that's brutal... I'd say for the through hole things I've soldered so far I have never broken anything. My joints are never particularly clean but they're also never dangerous or unreliable.

Also, I thought the optical switches were an enclosed unit like the mechanical switches just with a different internal design.

So what kind of mechanical switch should I buy (it appears to be 3.3V)?

I googled "Logitech M90 switches" and got lots of results...

 

[Frick]

So you guys mean I'm just supposed to YOLO it and try multiple ones till one fits?

No, you have the measurements. If it's like the switches used in other mouses it'll be just a micro switch and as such you can find replacements. What good replacements are I personally don't know, maybe someone else does. In ages past some Omron switches had good reputation, but aparently they don't anymore so I don't know sadly.

Jeez that's brutal... I'd say for the through hole things I've soldered so far I have never broken anything. My joints are never particularly clean but they're also never dangerous or unreliable.

Fair enough, through holes are easier than surface mount stuff (I myself is not a good solderer at all).

Also, I thought the optical switches were an enclosed unit like the mechanical switches just with a different internal design.

They might look the same, but from what I've managed to gather they have vastly different voltage requirements. I saw some specs on some Kalih switches and they said 30V.

I googled "Logitech M90 switches" and got lots of results...

Not optical though.

 

[sudothelinuxwizard]

I googled "Logitech M90 switches" and got lots of results...

I did too, but they seem to be the exact no name ones that are currently in there. I want to upgrade them

No, you have the measurements. If it's like the switches used in other mouses it'll be just a micro switch and as such you can find replacements. What good replacements are I personally don't know, maybe someone else does. In ages past some Omron switches had good reputation, but aparently they don't anymore so I don't know sadly.

Microswitches had 3 leads, the mouse only has 2 pads

 

[BlaezaLite]

I did too, but they seem to be the exact no name ones that are currently in there. I want to upgrade them


Microswitches had 3 leads, the mouse only has 2 pads

It's a £5.75 mouse. Invest in a better one? Seems like there is nothing available for it.

 

[sudothelinuxwizard]

It's a £5.75 mouse. Invest in a better one? Seems like there is nothing available for it.

I mean, I probably should, but I would like to just improve it if at all possible, I hate buying new stuff unnecessarily.

 

[BlaezaLite]

I mean, I probably should, but I would like to just improve it if at all possible, I hate buying new stuff unnecessarily.

Very responsible. Do you just want a mouse with optical switches?

 

[sudothelinuxwizard]

Very responsible. Do you just want a mouse with optical switches?

Not necessarily, just switches that are less crap (and don't get fed the wrong voltage cough cough modern Omron D2F mice).

 

[BlaezaLite]

Not necessarily, just switches that are less crap (and don't get fed the wrong voltage cough cough modern Omron D2F mice).

I'm no aficionado in mice, but just find something that looks good and you can research what switches they have.

 

[Bill_Bright]

This is a detour, but I thought stuff like in the attached image were manufactured to some kind of IPC standards or something

There are certain standards for electrical switches, sure. But those apply to things like current capability, EMI/RFI and other safety concerns based on the intended application of the component.

But that was not the question. The question was about the form factor - as in the size and shape of the component used in computer mice.

And considering computer mice these days use either the +5V from a USB port, or for wireless, typically 1.5 or 3V from a single AA or 2 AA batteries, the current levels involved are so small, current capability isn't even an issue.

and don't get fed the wrong voltage

Huh? What does that mean? As seen by the D2F data sheet, those switches are rated up to 250VAC @ 5A. So even if fed the "wrong" voltage, the worse case in a computer would only be 12VDC.

 

[sudothelinuxwizard]

Huh? What does that mean? As seen by the D2F data sheet, those switches are rated up to 250VAC @ 5A. So even if fed the "wrong" voltage, the worse case in a computer would only be 12VDC.

They often get fed 3.3V while the minimum is 5V. This leads to some phenomenon I do not fully grasp where they last less long then their rated lifespan because the lower potential difference can not bridge minor corrosion.

 

[Bill_Bright]

They often get fed 3.3V while the minimum is 5V. This leads to some phenomenon I do not fully grasp where they last less long then their rated lifespan because the lower potential difference can not bridge minor corrosion.

Ummm, nah. Sorry. Not how it works. You can see through the link in my signature I have a little knowledge of electronics. Got a link to an article explaining this "phenomenon"?

There is no minimum as far as the switch itself or its electrical contacts are is concerned. I mean think about it for a second. How much voltage is flowing through these switches when it is open (not being pressed) - which is the vast majority of the time? 0V.

There should be no corrosion. While these switches are not hermetically sealed, they are not designed, or intended to be used in outdoor environments or indoor environments that would be corrosive. Nor are they wide open to the elements in the room like skin oils or dust. And even so, the metal alloys used in these contacts are not prone to corrosion and, in fact, are coated with a protective anti-corrosive surface.

Now what might be causing this "phenomenon" you mention is "IF" the circuit is expecting 5V but only receiving 3.3V, that may cause the circuit to behave erratically.

In other words, the circuit may not work properly but the switch is not affected.

That said, not sure why or how they could be getting 3.3V anyway. The VCC in a USB port/cable is +5VDC. There is no 3.3V in a USB connected. And if a wireless mouse, the dongle still uses +5V.

So I am sorry but I fear you either misunderstood the issue, or someone was telling you BS.

 

[eidairaman1]

Not in the case of the mouses I've opened. Those have all either been those push button switches or micro switches. OP wants to replace them with optical switches though.

This is a detour, but I thought stuff like in the attached image were manufactured to some kind of IPC standards or something, like lead/hole size and stuff. Or is it just common sizes they use because everyone else use it?

Microswitches come in different sizes

 

[Frick]

Ummm, nah. Sorry. Not how it works. You can see through the link in my signature I have a little knowledge of electronics. Got a link to an article explaining this "phenomenon"?

There is no minimum as far as the switch itself or its electrical contacts are is concerned. I mean think about it for a second. How much voltage is flowing through these switches when it is open (not being pressed) - which is the vast majority of the time? 0V.

There should be no corrosion. While these switches are not hermetically sealed, they are not designed, or intended to be used in outdoor environments or indoor environments that would be corrosive. Nor are they wide open to the elements in the room like skin oils or dust. And even so, the metal alloys used in these contacts are not prone to corrosion and, in fact, are coated with a protective anti-corrosive surface.

Now what might be causing this "phenomenon" you mention is "IF" the circuit is expecting 5V but only receiving 3.3V, that may cause the circuit to behave erratically.

In other words, the circuit may not work properly but the switch is not affected.

That said, not sure why or how they could be getting 3.3V anyway. The VCC in a USB port/cable is +5VDC. There is no 3.3V in a USB connected. And if a wireless mouse, the dongle still uses +5V.

So I am sorry but I fear you either misunderstood the issue, or someone was telling you BS.

I did stumble upon an hour long video (that I haven't watched, but scrolling through it it seems extremely detailed) exploring this very topic and the bolded part seems to be the reason.

-the change from 5v to lower (3.3v) logic voltage and use of the MCUs' higher resistance internal pull-ups (~40k) necessitates a change in hardware design, which manufacturers have not caught up to yet
-the change to faster MCUs and higher polling rates necessitates more advanced firmware logic, which manufacturers have not caught up to yet
-the 'general purpose' switches we have been using don't work well at new voltages/currents/rates, and the ruggedized 50M versions are even more incompatible, and may 'fail' even faster than the lower cycle-life versions

Microswitches come in different sizes

Yes but the OP has measured the ones in the M90.

 

[silentbogo]

Recently, I've been having fancies about replacing the shitty unbranded switches in my Logitech M90 mouse with optical ones.

Optical switches won't work. While they may be the same form-factor, they require special driving circuitry and are not a drop-in replacement for mechanical ones.
Either get something like this(Kaihl reds are frequently used in newer gaming mice):

https://www.aliexpress.com/item/1005002703314477.html?spm=a2g0o.productlist.main.17.fefb6a44bpQ46n&algo_pvid=05436e9a-6629-478c-ab87-20c6080ea9ea&pdp_ext_f=%7B%22order%22%3A%2212%22%2C%22eval%22%3A%221%22%7D&utparam-url=scene%3Asearch%7Cquery_from%3A

... or just get a new mouse. M90 is pretty crap as-is (even if it works), no fancy switches can fix that.

 

[sudothelinuxwizard]

Ummm, nah. Sorry. Not how it works. You can see through the link in my signature I have a little knowledge of electronics. Got a link to an article explaining this "phenomenon"?

There is no minimum as far as the switch itself or its electrical contacts are is concerned. I mean think about it for a second. How much voltage is flowing through these switches when it is open (not being pressed) - which is the vast majority of the time? 0V.

There should be no corrosion. While these switches are not hermetically sealed, they are not designed, or intended to be used in outdoor environments or indoor environments that would be corrosive. Nor are they wide open to the elements in the room like skin oils or dust. And even so, the metal alloys used in these contacts are not prone to corrosion and, in fact, are coated with a protective anti-corrosive surface.

Now what might be causing this "phenomenon" you mention is "IF" the circuit is expecting 5V but only receiving 3.3V, that may cause the circuit to behave erratically.

In other words, the circuit may not work properly but the switch is not affected.

That said, not sure why or how they could be getting 3.3V anyway. The VCC in a USB port/cable is +5VDC. There is no 3.3V in a USB connected. And if a wireless mouse, the dongle still uses +5V.

So I am sorry but I fear you either misunderstood the issue, or someone was telling you BS.

Ah, sorry. My ADHD brain messed up terms, the actual problem is that 1 mA is below the wetting current of the D2F. It's enough that it works when new, but as corrosion builds up on the silver (as opposed to gold on better switches) contacts, the wetting current rises further and it stops working.

 

[Bill_Bright]

No sorry. ADHD or not, silver is rarely ever used in switches. It is too expensive and tarnishes too quickly. So again, you seem to have either misunderstood what was said, or were told a bunch of nonsense.

For the record, silver is the best conductor - better than gold. But it is not used because it tarnishes where gold does not. But of course, gold is too expensive. For those reasons, copper, brass, aluminum, even stainless steel is typically used in switch contacts, typically mixed with other metals as alloys to increase strength or prevent corrosion. When silver is used in more expensive switches it is always in an alloy - or in a hermitically sealed environment totally void of oxygen.

The example you use of wetting current is typically an issue where millivolts, microvolts and even lower potentials are involved in extreme environments (like high humidity) AND where small contact pressure is involved. These switches are not typically operated with such low voltage potentials or high humidity environments. And our fingers impose relatively large pressures when we press on the contacts.

I note where switching current is below the makers wetting current spec, this problem is easily mitigated by the use of small capacitor across the contacts. So again, not a problem here.

 

[Shrek]

So what kind of mechanical switch should I buy

The Kailh GM 8.0 is good for 8 million clicks.