05 Dec 2016, 04:35

So, something I've talked about for quite a while that affects most keyboard switches is "spring friction". Or said another way spring binding.



When springs are compressed, they are held into place in switches. The coils of the spring rub against the side of the housing causing additional resistance against the movement of the slider. The material, plating, lubricant and corrosion can have a lot to do with this to varying degrees depending on the switch design.



The number of coils may have a positive or negative affect as well. Few coils means less contact points, but each contact point applies more friction. More coils means more contact points and more chances to get caught on housing imperfections.



In terms of length of springs. this mainly matters for switch pre-load force. Otherwise it doesn't really matter.



Something don't see talked about very much (if at all) is vibrations/force transfer through the spring. When you compress a spring, it doesn't compress uniformly when the coils are being resisted by friction due to the housing. This causes force impulses to be transferred through-out the spring. I suspect this is one of the sources of noise on my force graphs, though it's pretty hard to validate without some sort of highspeed camera and the switch cut open.



Anyways, yep. Springs can affect how a switch feels. But I think the design of the switch itself is more important.