Anyone used one of these?

[xsphat]

http://cgi.ebay.com/IBM-PN-37L0888-Space-Saver-II-Keyboard-RT3200_W0QQitemZ260222611007QQihZ016QQcategoryZ51084QQrdZ1QQssPageNameZWD1VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247

If you have, was it alright to type on? I really don't care about anything else.

[victheslik]

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[graywolf]

I am not sure why, people think that. Rubber dome keyboards run from utter crap to pretty decent feeling. Of course none of them are clicky, and I doubt a serious gamer would be happy with one. But as a writer, I have found that a good rubber ducky keyboard is good enough to write on.

I was thinking of getting one of those Space Saver II's, but have commited for a different rubber ducky keyboard. My IBM M3 is halfway decent and is definitly a rubber ducky. Best $3 I ever spent.

But then they say membrane keyboards are crap too, forgetting that the Model-M is a membrane keyboard. So I guess it is fair to say cheaply made keyboards are crap; good ones, whatever their technology are good ones. But some of the good ones are not good for some uses. A keyboard that is great for writing on is not good for gaming, and vis versa.

However, none of that is an endorsement of the SSII, as I have never used one.

[bigpook]

So what passes for a good/decent rubber dome keyboard?

[Ulysses31]

People tend to speak highly of Cherry rubber domes, though the only one I ever used seemed to require a lot of key pressure.  That was ages ago though.

[lowpoly]

People tend to speak highly of Cherry rubber domes, though the only one I ever used seemed to require a lot of key pressure.  That was ages ago though.

Must have been the RS 6000, IMO one of the worse rubber domes.

[bigpook]

I have a HHKB Lite 2, which is rubber dome. Its okay, but not something I would want to use as my everyday keyboard.
I have used some Dell keyboards at work that were ok too. But once again, they aren't anything I would want to use on a regular basis.

[Ulysses31]

It looked like a G83 as I recall.  Either way the keys felt stiff but these were public computers and had probably been bashed to death.

[graywolf]

Let me just add a thought here, no rubber dome is going to feel good if you insist on bottoming it out. When you do that you are just pressing on rubber. However, if the dome is shaped to work as a spring with an over-center feel, and as long as you are using it in that range of movement, it feels OK (at least the better ones, and AFAIK, all the IBM RD's I have used are in that catagory). No rubber ducky has that hard stop mechanical keyboards have, it is just the nature of the material.

I am not saying that the best rubber dome keyboards are up to the best mechanical and bucklingspring keyboards, don't think that, but they are definately usable for writing. The Wiki article on them shows a cheap one, a good one has a lot more complicated shape than that and is designed so there is key travel beyond the contact point; that is critical to that over-center feel.

[Korbin]

Let me just add a thought here, no rubber dome is going to feel good if you insist on bottoming it out. When you do that you are just pressing on rubber. However, if the dome is shaped to work as a spring with an over-center feel, and as long as you are using it in that range of movement, it feels OK (at least the better ones, and AFAIK, all the IBM RD's I have used are in that catagory). No rubber ducky has that hard stop mechanical keyboards have, it is just the nature of the material.
QUOTE]

There is a slight problem with that.... you can't actuate a rubber dome swtich without bottoming them out.

The contact register is literrally at the bottom of the stroke.... as a opposed to mechanical switches that have 2 contact point that slide passed each other and meet in the middle of the keystroke.

[lowpoly]

There is a slight problem with that.... you can't actuate a rubber dome swtich without bottoming them out.

The contact register is literrally at the bottom of the stroke.... as a opposed to mechanical switches that have 2 contact point that slide passed each other and meet in the middle of the keystroke.

The small plunger that presses the membranes together is on a small rubber dome itself allowing further travel of the key:



There are three phases in a rubber dome keypress: First, the tactile feedback (you have this with the HHKB pro as well), second the contact phase during which the smaller rubber dome is pressed inwards. And third the stop which occurs either with the keycap making contact with the frame or the bigger rubber dome making contact with the membrane.

Obviously, these three phases are not easy to adjust.

[Korbin]

Perhaps graywolf is talking about using only enough pressure to bottom out the key on a membrane board?

It's pretty easy to tell if you need to bottom out the key on a membrane board by simply pressing hard enough to actuate the key and checking for travel after the key actuation. All of my membrane boards virtually have no travel at all after key actuation compared to the membrane switches and the HHKB switches.

[graywolf]

As you can see in the photo Sofa-King posted the rubber spring is actually two cups inverted to each other, the outer cup is the spring. When the inner cup hits it makes contact and then compresses some more, but contact is made before it bottoms out. What he showed a photo os a real high end RD key, but even the ones with with a onepiece whole keyboard rubber part can be made to actuate that way.

After thinking about it for awhile I realized that the Wikipedia article about them actually is showing a chicklet type keyboard that one has two parts the rubber with a contact surface on it, and the key matrix that it contacts. Whereas the keyboards I am talking about are rubber dome actuated membrane or even capacitive switches. The key presses the rubber dome down about 3mm to press the membranes together, then the inter dome has abut 1mm travel after that. Yes, that is rather limited travel compared to mechanical actuators.

Just to varify that I took my M3 appart; and yes, it works exactly that way. There is the top with the keys clipped into it, the rubber dome sheet, the matrix sheet, a clear sheet with holes in it, and then a power contact sheet under that.

I find it interesting that it appears to provide power at the matrix intersection point rather than at the edges of the matrix, although I never really bother to look that closely at other rubber duckies I have had apart.

[bigpook]

Man, that is one honking rubber dome : )

[lowpoly]

Macro FTW!

[Korbin]

After thinking about it for awhile I realized that the Wikipedia article about them actually is showing a chicklet type keyboard that one has two parts the rubber with a contact surface on it, and the key matrix that it contacts. Whereas the keyboards I am talking about are rubber dome actuated membrane or even capacitive switches. The key presses the rubber dome down about 3mm to press the membranes together, then the inter dome has abut 1mm travel after that. Yes, that is rather limited travel compared to mechanical actuators.

Ahhhh I see. I don't think I have ever typed on the membrane like the one sofa king posted. Nearly all of the ones that I type on are similar to the way wikipedia descibes them. The old microsoft boards I use to have were like this as well. Just like the HHKB lite 2, the keypress shaft sits on top of a rubber "bubble" and you have to push the key all the way down to actuate it.