Switches for pyra keyboard (Updated 2 may)

[comradekingu]

Metrics that are important:

Mounting: Must me smd mount only. (surface mounted) 
Width, height, depth 13CM wide by 4 cm max  Meaning 12x10 pcb space is the most that can be accomodated with a 11 key wide layout. Anything above 1CM tall including keycap is also not feasible. Regular desktop switches are out. Does anyone know the current dimensions for the pandora?
Actuation feel/travel A key that just collapses, like membranes do, isnt very nice, some are better than others, but springs (mechanical switches) are best. Not easy to get concerning the space requirements, more travel is better, but it costs depth (which directly translates to the thickness of the device.
Rated actuations Some even have 10 million actuations, mx cherrys (which is my benchmark reference) state 50 millions, thats extremely good.
Actuation force Thumb typing enables higher force keys to be used, but shouldnt be too high.  50-300g ish is common, or rated in newtons 0.50 to 3 newtons
Available keycaps With ready made keycaps that takes the guesswork out of making them, and it is better for colemaks and dvorakians since they can shift their keys around. Also makes it easier in dropping requirement for keymat (custom part) Its appealing because no effort would have to be put in making a keymat.
 
 

Good typing devices never die. And there certainly is a market for small tactile stuff nowadays.

Ideally a switch that will fit, with good keytravel and feel, which has a designated (detachable too) keycap already on it, delivered on smd reels, and placed by the pick and place machine, wave soldered, does away with some issues.

Making a keymat is custom, and it isnt flexible to different layouts. Also it takes manual labour to fit it, and it will considering equal efforts into each, wear out faster.  It also has to align with key-holes in the case. If that can be a square cutout then that means less complexity in the case itself.

OMRON:
 
http://www.omron.com/ecb/products/sw/21/b3f.html I love these, they have keycaps and everything

The omrons are specced for 1-3 mill actuations
The force required 100g and upwards, they are available in anything from 4x4 and up to 12x12 with the height starting at microswitch and up to nearly a cm.
Some keyboards have the keycaps and switches mounted on bare PCB with nothing in between, like this which is an easy way of not having to deal with buttons catching against the case and also less complexity in case manufacture.

http://www.omron.com/ecb/products/sw/24/b3al.html

1M 6.6 x 5.8  just too small. Keycap on plunger

It annoys me to no end that the b3f switches are through mount, but this is smd mount.
Checks out on everything, except its very high on the on the actuation force, over 5 times the cherry mx black.

oh oh, they actually are B3FS-1050    with b32 keycaps

6.6x6.6x7.3 high (without cap)

B32-2010 fits, its 6x6 round keycap.

Less than twice of the cherry mx black, which is good for thumb typing.
Rated for 1 Million min. actuations, which is supergood.
Price: switch 0,562 € (500+) keycap 0,667 € (500+)  so its expencive.



The downfall is the height though. 10mm required.

 

6mm round keycaps arent good. the 9 x 9  square ones are perfect, but they are only for 12x12 switches, which i dont think are available in smd

NKK:
http://www.mouser.com/ds/2/295/JBnonilluminated-30984.pdf

They are however expencive, but im thinking maybe they stack up so evenly one might not even need the case to be protruded for them to stick through.
Imagine that, a square cutout in the case where the keyboard fits.

http://no.mouser.com/ProductDetail/NKK-Switches/JB15LPE-JB/?qs=sGAEpiMZZMsgGjVA3toVBPWezmEh1yrrB7gE%2bS2lYII%3d

12.7 x 12.7 11.2 mm high on the pcb, making it just too big.  5M cycles, 1.67N 2.5mm travel Custom legends available.
 
Marquard:
Hurray, 10x10mm SMD mount, low profile, http://www.mouser.com/catalog/specsheets/Specifcation3006%20Series.pdf

And illumination.

4N, it had to be something...
 
C&K:
http://www.mouser.com/ds/2/60/K8%20Datasheet1-247592.pdf

Looking good thus far
 
WB:
 
TC002W
Also, http://www.mouser.com/ds/2/435/tc002w%20series-218404.pdf

9x8.5x8.6 mm  500k    Different colour LED and IP67 waterproofing

300g +-100g (standard)

180+-50gf

Plunger is the keycap, and can be ordered with symbols (ABCD→→↓→→) come preassembled on 350 part reel and can go directly through reflow soldering.

Price is 2.07 dollars with led and through hole.  For 5000,  10k is cheaper available on reel and cut tape

TC002

Same thing not waterproof, also the cap covers also the outside of the key.

http://www.wellbuying.com.tw/UP_pdf/tc002%20series.pdf states reflow soldering, needs manual assembly afterwards.

detachable caps, and  brings the price down to a dollar a key http://www.mouser.com/ProductDetail/Well-Buying/TC002-N11ASKKURUG/?qs=sGAEpiMZZMtRY1MQzfviYEe9%2fp1to2DP

Final price would be less than half, which puts the total at 30 dollars, which is reasonable.

180+-50gf

Available in tray packaging, dont know about reel.

And some im not sure about:
 
Panasonic:
http://www.mouser.com/ds/2/315/ATK0000CE42-264518.pdf

6.0 mm x6.1 mm, Height 5.0 mm  100k cycles

Mountain Switch:
http://www.mouser.com/ds/2/209/MS-100618-194133.pdf

9.50 x less x 7.30 h  500k  Looks like its easy to fabricate keycaps, but that doesnt scream mass production.

APEM:
http://www.mouser.com/ds/2/26/ADTS6-ADTSM-KTSC6-263747.pdf

Nice switch, 7.50x Less x 7.30 200k cycles  quite nice 12x12 premade keycaps but no lettering

ALPS:
Regular and cheap switch http://www.mouser.com/ds/2/15/SKQG-180836.pdf
ALPS is a very good selling point.  Can also get potmeters from alps.
They also have some news in their catalogue
 
E-Switch:
http://www.e-switch.com/product/tabid/96/productid/204/sename/tl6200-series-sealed-long-life-tact-switch/default.aspx#

Checks out on everything except it has high force 300g
Also available with preinstalled caps in 6.4mm height.  10M cycles and IP67  sadly they are 14 wide on the pcb
 
DTSH??
http://www.canal.com.tw/images/products/dtsh_m-2-6.htm
http://p.globalsources.com/IMAGES/PDT/SPEC/372/K1019050372.pdf
Semi low end ratings for actuations 100,000~500,000 cycles:

Need something for ABXY buttons too.

TLR  WB TC002W are the only ones without discerning flaws, and are pretty much ready to go from what i can tell.  If a very flat device is to be made, and keymat constructed for it, i would go with ALPS switches.

 

[_wb_]

Automatic message

This topic has been moved from "Pandora → General Talk" to "Pandora → Pyra Community Ideas".

 

[Binky]

My first thought:

Any switches used must be surface-mount, since the other side of the board (and all the layers in between)  is covered in connections for the SOC, screen, SD cards, wifi module, etc

 

[slaeshjag]

There are surface mount switches that *could* be used. However, having loose keycaps presents a hassle: You got 50+ keycaps to put in place during assembly. In the right place. That's a step that'll add considerable assembly costs.

 

[Binky]

How to manufacturers of normal cheapo keyboards do it?

They've got 100+ loose keycaps to fit

 

[slaeshjag]

They got cheap labour, and print (rather, laser-etch) the labels after assembly.

Germany is not the country of cheap labour, and I doubt labels will be printed after assembly.

 

[moxie]

By having standard keycaps (meaning that there exists machines for that particular tooling step) and building them in the tens of thousands to get the margins.

 

[comradekingu]

Components get placed by the pick and place machine and they come on reels that you feed into the machine. Myself i wouldnt be opposed to getting a little bag on the side with keycaps, but some of the options have keycaps already attached.

Edit: bold

 

[WizardStan]

What problem are mechanical switches solving here? Do you just like the feel of them better or is it something more? Is there perhaps something else we could use, changes to the rubber or something, that did the same thing or are switches the only option?

 

[slaeshjag]

Components get placed by the pick and place machine and they come on reels that you feed into the machine. Myself i wouldnt be opposed to getting a little bag on the side with keycaps, but some of the options have keycaps already attached.

Pick and place machines are used to place components on a PCB. Not to place keycaps in a case.

 

[Binky]

^ Presumably similar equipment could be used - but it might be hard finding a manufacturer that had it.

 

[Grench]

I'm excruciatingly picky on keyboards that I touch type on.  I type a lot.  I actually wear out high end keyboards - it takes a few years, but I've worn through a IBM PC/XT, three IBM PS/2 tactile click, one IBM soft-type (quiet tactile) and three HP workstation keyboards.  Yes, that is over 20 years.

Currently I'm using ThinkPad Ultranav keyboards at work & home.  They're holding up remarkably well.  They are a scissors over rubber dome based design.  The feel is good, the throw is relatively short but the action feels good.  Think of them as a mechanically guided rubber dome.  They're the same mechanism used in IBM and Lenovo Thinkpad laptops for many years - they've recently changed though.

Drawbacks to mechanical keyboards - backlighting becomes MUCH more difficult. as each key winds up having to have a functional light pipe coming up through the center.  Mechanical systems wear out and break.  When they do, they're expensive to repair.  My PS/2 tactile clicks cost me up to $150 a throw back in the day.  I got lucky and bought my UltraNav keyboards for $50 each NOS - I can't find them for under $180 now.  In small quantities like the Pandora and Pyra, using a mechanical keyboard could easily add $100+ to the price of each unit.

Let that sink in a bit.  The rubber dome mats are less than $10 each.  ANY mechanical system listed above is likely to cost at least $2 a key between parts cost, development and mounting.  That is a whole lot of additional features to be mounted on the board - and a whole lot more individual little things to go wrong.

Now, if i were planning to touch type on this unit, $100 would be well worth it.  Anyone planning to touch type on a Pyra needs to have their head examined.  It is a THUMB keyboard.  At some point, good enough is good enough for the thumbs.  If you want to do serious typing, plug in a keyboard and go to town.

I'm not opposed to adding expense to the Pyra where it is appropriate.  Screen, nubs, wifi, proper buttons in the shoulders instead of flapping corner crap.  However, there is also a law of diminishing returns in this.  The collapsing rubber dome Pandora keyboard is passable to OK.  Admittedly it is possible to do 'better'.  But I argue that for every small step better, you're going to multiply the costs of the keyboard by a factor of 5 or more.

There are several people who malign the keyboard on the Pandora because it is rubber dome and not a spring-break tactile click wonder.  Frankly, it's about perfect for my thumbs and my wallet.  Round top keys and all.  It's cheap to build, easy&cheap to replace, water & gunk resistant, gives good feedback, it's easy to find the 'right' key.  Frankly, I think it's as close to -perfect- as we're likely to get for a pocketable portable computing device.

 

[Caine]

Anyone planning to touch type on a Pyra needs to have their head examined.  It is a THUMB keyboard.  At some point, good enough is good enough for the thumbs.

Thanks, I often touch-type on the Pandora (back in the days I used to do that on my calculator in high-school as well) .
On any regular PC I would not settle for anything other than buckling springs, but for a mobile device mechanical switches seem like massive overkill.

 

[Tenka]

Sounds very hard to clean.  How long will it take to drain and cleanse all of the hollow metal buckling spring keys after dropping it in the toilet?  The rubber keymat wouldn't even let most small spills get to the circuit board.  For my own tastes and comforts though, I would love the same round topped rubber keypad, but with keys that press in and slide back out smooth, instead of with a bump, some light difficulty pressing, and for the keys to register on almost the very slightest depth, maybe 1/32".

 

[Binky]

You drop your expensive electronics in the toilet?

 

[Caine]

When I consider the toilet-worthiness of a mobile device I think of entirely different things than how easy it is to clean after dropping it in the bowl

 

[Grench]

Anyone planning to touch type on a Pyra needs to have their head examined.  It is a THUMB keyboard.  At some point, good enough is good enough for the thumbs.

Thanks, I often touch-type on the Pandora (back in the days I used to do that on my calculator in high-school as well) .

On any regular PC I would not settle for anything other than buckling springs, but for a mobile device mechanical switches seem like massive overkill.

When I'm using my Pandora, my wife often comments, "The Keebler Elves called.  They want their computer back."  Seriously.  You can touch type on an 97mm wide home row?  Normal is 170mm wide.  I'm a fairly big guy (1.9M) with admittedly large hands, but mashing them together on a ruler - without gaps - my eight typing fingers are just shy of 140mm wide.  For you to be able to touch type at all on the Pandora, you'd need to be able to do the same thing inside of 86mm.  That is impressive.

 

[Caine]

Seriously.  You can touch type on an 97mm wide home row?  Normal is 170mm wide.  I'm a fairly big guy (1.9M) with admittedly large hands, but mashing them together on a ruler - without gaps - my eight typing fingers are just shy of 140mm wide.  For you to be able to touch type at all on the Pandora, you'd need to be able to do the same thing inside of 86mm.  That is impressive.

I have fairly large hands myself. It depends on how strict you define touch typing I suppose.
I do type using all my fingers (also on the Pandora) but I do not use the strict finger/key correlation that real touch typists do (sometimes I strike the same key with different fingers), but it gets VERY close to official touch typing.

 

[Granitehead]

From PMs:

At 2 dollars per switch for

63 keys its 126 dollar

They are cheaper in quantities of 10k and cheaper without the leds.

I couldnt find any info for the wb switches, but most of them come on smd mount reels, which the pick and place machines route onto the board to get soldered. I think they have to be spot soldered rather than wave soldered, unless the silicone is heat resistant.

You can see the pick and place machine on youtubne in the tour of GC video ed did.

SMD soldering the switches isn't the problem (I know this is automated), and I'm pretty sure there are cheap switches available (personally I would be willing to pay $50 more for a very good keyboard).

The problem is case assembly, you have one labeled key cap per key which needs to go to the right place.

I tried explaining my view in the switches thread http://boards.openpandora.org/topic/15368-switches-for-pyra-keyboard-updated-13-jan/?p=304698

I didnt understand the problem you described.

The keys are on the switch already, lets say they are sequentially put 1-63 on a reel, then the gerbers say nr 1 go 1.1 nr 2 go 1.2 in a matrix, its either that or all the A keys come on one reel

The number of components far outweigh the number of keys, so they must have enough reels to feed off.

So you get those switches with the labeled key tops already on them and solder them that way? I don't know if this is possible, but I think usually you have a switch which you solder to the board and then you have a seperate key cap which needs to be put on top of the switch while assembling the keyboard.

But then it came to my mind that actually maybe it's possible to use one big rubber keypad even with individual switches under it. I've got a simple mobile phone here with nice keys (no full keyboard, I just like the individual keys) and it's got one big key mat for all the keys. I don't want to open it right now (don't know how and it's water tight which probably makes opening it more complicated than usual), but I'm pretty sure that there is just a pcb with smd switches under that key mat.

I'm taking the liberty of publishing those pms in your thread, I think they contain information which is useful to everyone and can maybe clear some stuff up. We should continue our discussion there.

So now that I got what he wanted to say (I think), I have two questions:1. Is it possible to get SMD switches with labeled keycaps already on them on reels and then place them with the pick and place machine?

2. Maybe it's also a possibility to have one big key map and just place switches on the pcb instead of those blank pad-thingys?

 

[sebt3]

From PMs:

publishing content of private message in public is not a good etiquette no matter what the content is...