Does stacking o-rings provide the same result as using a thicker o-ring?

[Franck Dernoncourt]

I plan to add o-rings in my mechanical keyboard. Does stacking o-rings provide the same result as using a thicker o-ring, from the standpoint of the keyboard user?

For example, I could use two o-rings stacked on top of each other (1.5mm + 2.5mm), or directly use a 4mm o-ring.

[ddot]

Send Lpwl that question.  He has his own vendor sub forum:
https://geekhack.org/index.php?board=189.0

Before that he was just operating out of the classifies, but he talked about stacking a bit in this post:
https://geekhack.org/index.php?topic=62935.msg1652742#msg1652742

[Malenky]

Assuming you're talking about adding them to Cherry MX keys, then I'd imagine they feel pretty similar. Potentially stacked o-rings might feel *slightly* softer because I'd imagine they would allow for slightly more compression when compared to a single o-ring of equivalent thickness. Be careful though, Cherry MX switches have 4mm of travel, so 4mm of o-ring will make your keyboard unusable, unless you're using SA profile keycaps, which are really tall (in which case, you'd basically be stacking o-rings to pad the distance until they actually had any sort of effect).

[Lpwl]

I wasn't home last week-end, so I answered Franck's question directly via e-mail but I guess a few words here might also help a few wanderers ...

Does stacking o-rings provide the same result as using a thicker o-ring, from the standpoint of the keyboard user?

The answer is both yes and no.

It depends on what keycaps you are using !

For example, if you are using SP DSA profile caps then 4mm ≠ 1.5mm + 2.5mm.

And from my testing, anything thicker than 3mm will stop you from being able to actuate every switch comfortably.

Further reading :

[1]  O rings for DSA Caps
[2]  Lpwl O-Rings - FAQ & HELP
[3]  hjc1710's comment from my older sale thread

----

Thank you again ddot for referring him to me 

[MOZ]

I wasn't home last week-end, so I answered Franck's question directly via e-mail but I guess a few words here might also help a few wanderers ...

Does stacking o-rings provide the same result as using a thicker o-ring, from the standpoint of the keyboard user?

The answer is both yes and no.

It depends on what keycaps you are using !

For example, if you are using SP DSA profile caps then 4mm ≠ 1.5mm + 2.5mm.

And from my testing, anything thicker than 3mm will stop you from being able to actuate every switch comfortably.

Further reading :

[1]  O rings for DSA Caps
[2]  Lpwl O-Rings - FAQ & HELP
[3]  hjc1710's comment from my older sale thread

----

Thank you again ddot for referring him to me 

Out of curiosity, is it because the 4mm has a larger OD compared to the the 1.5mm and 2.5mm rings?

[Lpwl]

Yup, you're right - though I think this has more to do with SignaturePlastics keycaps lacking cross-shaped supports.