On 2019.04.08 14:25, Dan Ritter wrote:
IBM Buckling Spring: nobody knows, but there are a lot of
keyboards still working 25-30 years later.
Cherry: 50 million.
https://www.cherrymx.de/_Resources/Persistent/e005dff11a2e406babe9e8718fec9fc8835bb9ce/EN_CHERRY_MX_BLUE_RGB.pdf
Kailh: 50 - 80 million.
http://www.kailh.com/en/Products/Mechanical_keyboard_switch/165.html
Matias ALPS: 50 million.
http://matias.ca/switches/click/
Gaterons may be as low as 20 million.
You can buy all of the above today, in keyboards ranging from
about $60 to $450.
I had in mind a boxful of Logitech and Kessington keyboards purchased
several years ago, as well as two Cherry purchased last year.
The Cherry specifications gave me high hopes regarding Cherry, and I
paid a good price for the Cherry; but the switches of two of the three I
purchased new are beginning to fail.
The old IBM you mention, of course, is of the category I mentioned, a
design of another era.
As to keystroke specifications, I must question current test procedures.
In years past, I have experienced key plunger binding long before
contact failure was evident. Plunger design does not always take into
account the reality of lateral force on the keycap. The application of
lubricant is no substitute for proper material selection regarding
plunger and tube or body. Nowadays, contact failure seems to be the
primary failure mode. Many factors must be considered in the design of
a keyswitch.
Only with a warranty which provides advance replacement with no-charge
delivery and return would I consider paying much over a hundred dollars
for a keyboard. When the cost of return shipping by UPS, FEDEX, or USPS
is taken into account, a lifetime warranty on a $25 or $50 keyboard is
meaningless.
RLH