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geekhack Community => Keyboards => Topic started by: ideus on Sat, 26 December 2015, 18:29:18

Title: On keyboard science: MX Switch spring's Hooke module estimation.
Post by: ideus on Sat, 26 December 2015, 18:29:18

Propose your best method to determine the Hooke's module of springs that best relate with the "typing-feeling" they will offer.


Some concerns:


1. The MX switch final experience depends on more factors than the spring alone, as stem design and housing material.
2. Hooke's law relate distance and force to elongate or compress the spring with a known K module; thus, it would be easier to measure the length a spring elongates to when it is loaded with a known weight, instead of trying to measure the module directly.
3. An alternative would be to measure the force needed to compress an assembled switch and report a load required for it and for a particular combination of spring and stem.


Your thoughts wanted.

Title: Re: On keyboard science: MX Switch spring's Hooke module estimation.
Post by: neverused on Sat, 26 December 2015, 19:14:27

I have an instron at work, there's a small chance that I could rig up a switch tester in order to correlate the force profile during depression and the point of actuation. I'm not sure if that information is already available though, seems like it should be from Cherry.


Also do you only want to collect data on certain switches and find an average for hookes modulus? Do you see a benefit in swapping the springs and stems rather than just using an assembled switch? If you expect enough variation in just the housings, I feel that the data may not represent a very large population. Lastly, what kind of statistical sampling plan did you have in mind?

Title: Re: On keyboard science: MX Switch spring's Hooke module estimation.
Post by: ideus on Sat, 26 December 2015, 19:43:51

I can prepare a simple design of experiment's table using Fedorov's to get the best possible data with the lowest possible runs, considering only Hooke's law as the model.

Title: Re: On keyboard science: MX Switch spring's Hooke module estimation.
Post by: neverused on Sat, 26 December 2015, 19:53:32

Quote from: ideus on Sat, 26 December 2015, 19:43:51

I can prepare a simple design of experiment's table using Fedorov's to get the best possible data with the lowest possible runs, considering only Hooke's law as the model.

Interesting, I'm super busy at work and I'd have to try to schedule time out on the equipment, but if no one else steps up I may be able to help. If you draft the plan, can I take a look at it by any chance? The engineer in me can't help but be curious.

Title: Re: On keyboard science: MX Switch spring's Hooke module estimation.
Post by: E3E on Sun, 27 December 2015, 17:09:11

I love keyboard science. This is a little over my head, but I'd love to see the findings that you guys make here. I'll have to read a bit about Hooke's law tonight. :)

Title: Re: On keyboard science: MX Switch spring's Hooke module estimation.
Post by: SamirD on Thu, 31 December 2015, 11:42:39

Quote from: E3E on Sun, 27 December 2015, 17:09:11

I love keyboard science. This is a little over my head, but I'd love to see the findings that you guys make here. I'll have to read a bit about Hooke's law tonight. :)

Seriously, love all the super intelligent people on here.  Can't wait to do more reading and learning.  :thumb: