geekhack Community => Keyboards => Topic started by: rampantandroid on Tue, 28 July 2020, 15:55:59

Title: Dampening rubber in Zilent V2 switches deforms with use
Post by: rampantandroid on Tue, 28 July 2020, 15:55:59
I recently used some Zilent V2 switches I'd had sitting around since March in my new CTRL, and I've been using them for a few days now. In trying to help silence the keyboard, I noticed that some switches had more pre-travel than others, namely the ones I use versus the ones I don't (F keys for example). Disassembling the switches, it looks like the rubber at the top of the slider is deforming with use - the rubber is no longer as tall as it was new, resulting in the slider returning to a higher position than it did when new, and added some pre-travel as a result. Is this expected or normal?

Unused stem on the left, used stem on the right: (

Here's a short video showing the difference in pre-travel, with my pressing the switches with roughly the same force: (

I've also contacted ZealPC - I'll update this post if/when he replies.

Title: Re: Dampening rubber in Zilent V2 switches deforms with use
Post by: parablol on Tue, 28 July 2020, 16:43:41
Thanks for sharing. Perhaps that is just the breaking-in phase? But the inconsistient pre-travel is a concerning issue.

Tangent: I noticed that the dampening material in Outemu Sky Silent switches is unlike what Cherry, Gateron, and ZealPC use. It's relatively clear and seems to be a defferent material entirely. I just installed some & will see how it plays out. I just wish their actuation point wasn't so low.
Title: Re: Dampening rubber in Zilent V2 switches deforms with use
Post by: jackrabbit on Wed, 29 July 2020, 14:17:19
The increased pre-travel is consistent with the dampening pads getting squashed. The shorter rubber pad means the stems sit higher up when not pressed, so they have to be pushed down further before they reach the actuation point.

Unless elasticity can be improved, I suspect this is always going to be a tradeoff with silencing performance. The softer the pad is, the better it is at silencing, but the more easily it gets squashed. If you make the pad harder/stiffer to resist getting deformed, then it won't silence as well. However, if it's possible to use a rubber with better elasticity, it can be soft and also keep returning to the same shape after more presses.

But I bet the switch manufacturers already considered these material properties when they selected a type of rubber to use, and they aren't going to suddenly find a better material just because we ask them to. They can't just use the best material theoretically possible--their choices are limited to rubbers that are 1) compatible with the machines and manufacturing processes they use, and 2) available at a competitive price from suppliers. I'm sure if there was a better rubber that met both of those criteria, they would probably have it by now. I'm just some guy. You can bet a professional manufacturer has put more thought into it than I just did.