Why were model Ms only 2kro?

[supamesican]

Model Fs were nkro, as are most mechanical keyboards today, I know model ms were made as a cost cutting measure but still I don't understand why they are/were only 2kro but most other mechanical keyboards are nkro.

[Findecanor]

Because underneath the buckling springs and plastic hammers, there are membranes just like on most rubber-dome keyboards.
Each hammer press the membranes together underneath it when its spring buckles, closing a circuit.

The Model F have capacitative hammers over a slightly bendy circuit board, and the n-key rollover comes for free when using capacitative sensing. It is difficult to solder diodes to membranes, and for most office use you don't really need n-key rollover.

[mougrim]

Yeah. F > M. Though M were great boards, even modern Unicomp USB-interfaced boards only 2KRO.

[supamesican]

I know 2kro doesn't matter for office work, heck even for most games I've played 2kro doesn't seem like it would matter much. Probably because most people have rubber dome, and devs account for that. Kinda sucks thats something they cut out, but eh I can see why. I guess thats why we have topre and cherry mx switches for alternatives.   


Wonder if it would be possible to use a usb hub on the usb to get around the 2kro, like some companies do to get passed the 6kro limit usb has built in, or theres anything unicomp could do to get more than 2kro..

[esoomenona]

.

[dorkvader]

I know 2kro doesn't matter for office work, heck even for most games I've played 2kro doesn't seem like it would matter much. Probably because most people have rubber dome, and devs account for that. Kinda sucks thats something they cut out, but eh I can see why. I guess thats why we have topre and cherry mx switches for alternatives.   


Wonder if it would be possible to use a usb hub on the usb to get around the 2kro, like some companies do to get passed the 6kro limit usb has built in, or theres anything unicomp could do to get more than 2kro..

there's a few things that affect the KRO of a keyboard. IF the keyboard matrix supports NKRO but the protocol doesn't then you end up with 6KRO (usually). So even if they did some of the tricks to get around the 6kro limit for USB, they cant get around the limit of the keybaord matrix hardware.

Now I have thought up a way to make a model M membrane NKRO with a pile of diodes and three or four 30-pin connectors and some custom membranes, but this relies on getting some custom membranes made.

[mougrim]

They'd have to stop making the keyboard in its current state and redesign something completely different. I don't think there is any other way around it.

Or just start producing Model F ones. Hell, model F already almost re-created by community.

[Vizir]

[...] Hell, model F already almost re-created by community.

really? got any info/link?

[mougrim]

[...] Hell, model F already almost re-created by community.

really? got any info/link?

Here you are.

http://geekhack.org/index.php?topic=51767.0

[fohat.digs]

And this one:

http://geekhack.org/index.php?topic=52379.msg1160353#msg1160353

[Findecanor]

Now I have thought up a way to make a model M membrane NKRO with a pile of diodes and three or four 30-pin connectors and some custom membranes, but this relies on getting some custom membranes made.

I have thought of the same thing. I think that the bottom membrane could be replaced with a semi-flexible PCB with surface-mounted diodes, but then there need also be holes in the back plate and/or membranes to accommodate those diodes. The entire keyboard assembly would also be thicker.

Or just start producing Model F ones. Hell, model F already almost re-created by community.

That was changing the layout for Model F using existing Model F parts. I doubt that tooling would exist for making new capacitative hammers.
The thing with Model M is that Unicomp still makes them.

[katushkin]

Because underneath the buckling springs and plastic hammers, there are membranes just like on most rubber-dome keyboards.
Each hammer press the membranes together underneath it when its spring buckles, closing a circuit.

The Model F have capacitative hammers over a slightly bendy circuit board, and the n-key rollover comes for free when using capacitative sensing. It is difficult to solder diodes to membranes, and for most office use you don't really need n-key rollover.

Ahhhhhhhhh. This gives me a lot more understanding of BS boards

+1 quality post

[dorkvader]

Now I have thought up a way to make a model M membrane NKRO with a pile of diodes and three or four 30-pin connectors and some custom membranes, but this relies on getting some custom membranes made.

I have thought of the same thing. I think that the bottom membrane could be replaced with a semi-flexible PCB with surface-mounted diodes, but then there need also be holes in the back plate and/or membranes to accommodate those diodes. The entire keyboard assembly would also be thicker.

Or just start producing Model F ones. Hell, model F already almost re-created by community.

That was changing the layout for Model F using existing Model F parts. I doubt that tooling would exist for making new capacitative hammers.
The thing with Model M is that Unicomp still makes them.

So I thought of that as well, but I have my suspicions that the copper will delaminate from the PCB, so my current idea is to use only matricies and solder the connectors onto a controller PCB with all the diodes and the entire matrix on it.

SMD diodes will actually fit under the channels that seat the hammers, I believe.

[mougrim]

That was changing the layout for Model F using existing Model F parts. I doubt that tooling would exist for making new capacitative hammers.
The thing with Model M is that Unicomp still makes them.

The are nothing exactly "magic" about capacitive hammers. We were discussing issue of hammets there... It's just conductive plastic, and I'm pretty sure it could be printed on the one of more high-grade 3d-printers.

Case/barrels is more of issue... but I was thinking about some acrylic for case...

[dorkvader]

That was changing the layout for Model F using existing Model F parts. I doubt that tooling would exist for making new capacitative hammers.
The thing with Model M is that Unicomp still makes them.

The are nothing exactly "magic" about capacitive hammers. We were discussing issue of hammets there... It's just conductive plastic, and I'm pretty sure it could be printed on the one of more high-grade 3d-printers.

Case/barrels is more of issue... but I was thinking about some acrylic for case...

I was thinking a normal-non conductive plastic flip plate with a conductive strip on it could work well, but would likely require more labour to produce.

[JPG]

Does it need to be metallic? When I was looking at some info on capacitance, all materials have a different dielectric constant (value that determine if it's easy to detect or not with capacitance). But plastic is hard to detect because it's low. But if we found a mix that was easier to detect (or have a plastic mixed with something else) OR have a very precise sensor then it could still work.


I don't have much knowledge on this, just a few articles on the net I *tried* to understand.

[mougrim]

That was changing the layout for Model F using existing Model F parts. I doubt that tooling would exist for making new capacitative hammers.
The thing with Model M is that Unicomp still makes them.

The are nothing exactly "magic" about capacitive hammers. We were discussing issue of hammets there... It's just conductive plastic, and I'm pretty sure it could be printed on the one of more high-grade 3d-printers.

Case/barrels is more of issue... but I was thinking about some acrylic for case...

I was thinking a normal-non conductive plastic flip plate with a conductive strip on it could work well, but would likely require more labour to produce.

Maybe, but we will need F flip plates anyway, so I think it better to produce it from conductive plastic. Besides, it'll last longer than conductive strip... Of course if conductive plastic not expensive - but it's basically just plastic with graphite mixed in it.

[mougrim]

Does it need to be metallic? When I was looking at some info on capacitance, all materials have a different dielectric constant (value that determine if it's easy to detect or not with capacitance). But plastic is hard to detect because it's low. But if we found a mix that was easier to detect (or have a plastic mixed with something else) OR have a very precise sensor then it could still work.


I don't have much knowledge on this, just a few articles on the net I *tried* to understand.

Nah, in model F it ain't matal. Just plactic mixed with something conductive. I'd say graphite. It's cheap.

[dorkvader]

Does it need to be metallic? When I was looking at some info on capacitance, all materials have a different dielectric constant (value that determine if it's easy to detect or not with capacitance). But plastic is hard to detect because it's low. But if we found a mix that was easier to detect (or have a plastic mixed with something else) OR have a very precise sensor then it could still work.


I don't have much knowledge on this, just a few articles on the net I *tried* to understand.

Nah, in model F it ain't matal. Just plactic mixed with something conductive. I'd say graphite. It's cheap.

Some sort of carbon for sure.

It doesn't have to be metallic but it does have to move electrons. The more the better (easier to detect).

Someone earlier said about 3D printing the flip plates. There are some issues with that method. One is that I'm not aware of much choice for extruded metallic plastic (and there  may be issues with conductivity of it. The other is the issue with all 3D printed stuff: will it be precise enough to actually work. Last I checked, 3D printed F flip plates exist but the tolerances from shapeways is not good enough for them to buckle correctly.

[Oobly]

I'm experimenting with thin aluminium tape on an M hammer plate (it can be shaped nicely over the contours and won't oxidise like exposed copper can) and shellac coated copper tape pads (the shellac protects them from oxidising and works nicely as a very thin dielectric layer) connected with magnet wire to the controller (small surface area to prevent parasitic / stary capacitance). Haven't got very far yet, though. Planning to use something similar to xwhatsit's method of detecting presses, including calibration.

The M hammer plates have a lot less surface area than the F ones, but I think they should work well enough.

[mougrim]

Does it need to be metallic? When I was looking at some info on capacitance, all materials have a different dielectric constant (value that determine if it's easy to detect or not with capacitance). But plastic is hard to detect because it's low. But if we found a mix that was easier to detect (or have a plastic mixed with something else) OR have a very precise sensor then it could still work.


I don't have much knowledge on this, just a few articles on the net I *tried* to understand.

Nah, in model F it ain't matal. Just plactic mixed with something conductive. I'd say graphite. It's cheap.

Some sort of carbon for sure.

It doesn't have to be metallic but it does have to move electrons. The more the better (easier to detect).

Someone earlier said about 3D printing the flip plates. There are some issues with that method. One is that I'm not aware of much choice for extruded metallic plastic (and there  may be issues with conductivity of it. The other is the issue with all 3D printed stuff: will it be precise enough to actually work. Last I checked, 3D printed F flip plates exist but the tolerances from shapeways is not good enough for them to buckle correctly.

It sure exists... Like this one: http://www.makergeeks.com/coabs3dfi10.html

About tolerances... Hmm, this calls for some research. Maybe those flip plates were printed on home-grade printers?

[tp4tissue]

Freaking...  Because people back then did WORK on computers..  they didn't just sit around playing video games..

[0100010]

If we can't get capacitive pivot plates / flippies / hammers printed, what about this idea : http://geekhack.org/index.php?topic=57879.0

[mougrim]

If we can't get capacitive pivot plates / flippies / hammers printed, what about this idea : http://geekhack.org/index.php?topic=57879.0

1) Probably will be expensive as hell.
2) Why?

[mougrim]

If we can't get capacitive pivot plates / flippies / hammers printed, what about this idea : http://geekhack.org/index.php?topic=57879.0

1) Probably will be expensive as hell.
2) Why?

[supamesican]

Does it need to be metallic? When I was looking at some info on capacitance, all materials have a different dielectric constant (value that determine if it's easy to detect or not with capacitance). But plastic is hard to detect because it's low. But if we found a mix that was easier to detect (or have a plastic mixed with something else) OR have a very precise sensor then it could still work.


I don't have much knowledge on this, just a few articles on the net I *tried* to understand.

Nah, in model F it ain't matal. Just plactic mixed with something conductive. I'd say graphite. It's cheap.

Some sort of carbon for sure.

It doesn't have to be metallic but it does have to move electrons. The more the better (easier to detect).

Someone earlier said about 3D printing the flip plates. There are some issues with that method. One is that I'm not aware of much choice for extruded metallic plastic (and there  may be issues with conductivity of it. The other is the issue with all 3D printed stuff: will it be precise enough to actually work. Last I checked, 3D printed F flip plates exist but the tolerances from shapeways is not good enough for them to buckle correctly.

It sure exists... Like this one: http://www.makergeeks.com/coabs3dfi10.html

About tolerances... Hmm, this calls for some research. Maybe those flip plates were printed on home-grade printers?

That is really interesting, that very well could be exactly what is needed.