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geekhack Community => Other Geeky Stuff => Topic started by: typo on Sun, 05 September 2010, 02:39:57

Title: mechanical switch adding machines?
Post by: typo on Sun, 05 September 2010, 02:39:57

where there any mechanical switch adding machines? i have some rather high end machines but they are not mechanical. they don't seem to be rubber dome either. i don't know what they are. i was wondering if nicer machines exist?

Title: mechanical switch adding machines?
Post by: vils on Sun, 05 September 2010, 02:47:39

Here  (http://web.telia.com/~u13101111/calctype.html) we have a few...

Title: mechanical switch adding machines?
Post by: WhiteRice on Sun, 05 September 2010, 22:53:06

somebody call babbage

Title: mechanical switch adding machines?
Post by: typo on Mon, 06 September 2010, 01:54:44

i meant a more modern printing calculator. sorry i didn't clarify. like from the 1980's to present. i don't see why such specialized machines did not usually have cherry or buckling switches. i have many of them but none seem to have mechanical switches. not even ones that were expensive in their day.

Title: mechanical switch adding machines?
Post by: Konrad on Mon, 06 September 2010, 03:45:08

I don't think they ever used mechanical switches.  Corner-cutting by manufacturers was invented long before the 1980s, a decade which saw them gleefully embrace the profitable wonders of low-cost digital technology.
 
You might have better luck finding such switches on cashier machines, though I'd suspect many (if not most) would've used membrane switches, a good (and cheap) choice where resistance to bumbling unwashed teenagers or spilled liquids would be necessary for long term use.

Title: mechanical switch adding machines?
Post by: ch_123 on Mon, 06 September 2010, 04:29:01

Here you go. (http://oldcalculatormuseum.com/sperryedc3.html)

(http://oldcalculatormuseum.com/edc3int.jpg)
(http://oldcalculatormuseum.com/edc3kbstalk.jpg)

Hall Effect switches, with an expected lifetime somewhere in the hundreds of millions to billions. Not sure why you'd need that on a calculator, but what the heck...

Title: mechanical switch adding machines?
Post by: typo on Mon, 06 September 2010, 06:39:50

yeah, remington edc-iii will do the job. i can only imagine what that would cost if i found one. i suppose that is not like great crt's that are now worthless. man i would love to have that. i had used one back then at an office but i never owned one. the way that is built compared to todays smd stuff, well it would be like owning a time machine!

Title: mechanical switch adding machines?
Post by: Konrad on Mon, 06 September 2010, 06:51:24

omg, are those nixie tubes???
 
If they are ... and if they work ... they'd easily be worth enough to buy a thousand times their weight in mechanical keyswitches ... ten thousand times their weight if sold as a set of matched parts.

Title: mechanical switch adding machines?
Post by: TheSoundofTyping on Mon, 06 September 2010, 09:10:39

Hall-effect switches should be the next switch technology that keyboard companies work towards selling.  Hey, there's a whole forum of us who'll spend stupid amounts on keyboards already; why not? :P

Title: mechanical switch adding machines?
Post by: ch_123 on Mon, 06 September 2010, 09:22:16

Expensive, bulky, probably hard to fit some sort of tactile mechanism in it, and ultimately unnecessary.

I mean, people are using 20 year old Model Ms that only have a life span of 25 million presses. Do we really need something that lasts a few billion.

Title: mechanical switch adding machines?
Post by: Konrad on Mon, 06 September 2010, 09:43:07

Some of us can type really fast.

Title: mechanical switch adding machines?
Post by: PAINKILLER on Mon, 06 September 2010, 12:37:30

If some nuclear power plant around you is closing, has closed, or has blown up, you might have a good source for hall-effect switches. Other candidates I guess are ICBM silos, underground bomb shelter control centers, war rooms, etc. You better have something like that around and a PC similarly long-lasting and resistant to nuclear EMP attack, cause you never know!

Title: mechanical switch adding machines?
Post by: HaaTa on Mon, 06 September 2010, 12:41:31

It makes one wonder why an ICBM silo needs switches that will last a few billion key presses...

Title: mechanical switch adding machines?
Post by: ch_123 on Mon, 06 September 2010, 12:43:14

Just don't use Blue Cherries. You don't want a stray hair destroying your first strike capability...

Title: mechanical switch adding machines?
Post by: PAINKILLER on Mon, 06 September 2010, 12:46:31

Quote from: HaaTa;220436

It makes one wonder why an ICBM silo needs switches that will last a half billion key presses...

Well you don't want a 1 in a million chance of having a stuck or broken key.

Title: mechanical switch adding machines?
Post by: Konrad on Mon, 06 September 2010, 12:57:27

You'd probably be better off building your own. Cast or machined from scratch or cannibalizing existing mechanical keyswitches to mod with a Hall-effect sensor refit and magnetic contact points; it actually wouldn't cost too much because you could order 100+ quantity at ~$0.27 each ... do it right and you could easily match the high-spec mass production units for quality and longevity.
(http://img.himfr.com/1115500347110149100/Hall_Effect_Fan_Motor_Switch_OH277.jpg)

Title: mechanical switch adding machines?
Post by: Superfluous Parentheses on Mon, 06 September 2010, 13:08:38

I know it's not what the OP is asking, but these things are very cool (http://www.retrothing.com/2006/05/curta_miniature.html)

Title: mechanical switch adding machines?
Post by: PAINKILLER on Mon, 06 September 2010, 13:35:27

Quote from: ripster;220445

Show Image

(http://farm5.static.flickr.com/4106/4964684762_9cf84017a9_z.jpg)

I was expecting something like:

(http://www.thetoyzone.com/wp-content/uploads/2008/10/dr-strange-love.jpg)

Quote from: Konrad;220447

it actually wouldn't cost too much because you could order 100+ quantity at ~$0.27 each ...

That much for hall-effect switches? Not bad. But this picture you posted seems to be something for fan RPM control.

Title: mechanical switch adding machines?
Post by: Konrad on Mon, 06 September 2010, 14:33:10

That's exactly what it is. It senses fan rpm and switches on/off as necessary. There are zillions of different Hall-effect parts to choose from; I chose this one only because it was the first cheap part I found that (I think) would be small enough to fit in a key (in the cap, stem, or base). Just a quick example of type, not necessarily the only part that you could use.

Title: mechanical switch adding machines?
Post by: typo on Mon, 06 September 2010, 21:50:38

on old cars there are hall effect sensors on some carburators. they show up in a lot of old machinery.

i wish to have that remington. i bet it is worth a fortune now though. you can find nixi stuff, it is just the whole thing that is so cool. since it is so haphazardly put together seemingly. that is what makes it cool imo. an early attempt at electronics.