Capacitive vs Regular (membrane) Buckling Spring Tactility?

[zx_spectrum]

I know very well the sound difference between capacitive and membrane buckling spring switches.
i own a model m keyboard and i have watched a lot of videos for sound comparison.
but i would like to know the difference in tactility between these switches:
clickyness , stiffness, weight, linearity level .. every thing that make any differences in the typing experience (except the sound)

[fohat]

I have always argued that the multiple metal plates forced into tension and compression is what makes the Model F feel so "alive" (as well as creating the "ringing" or "singing" sound that some people seem to love) similar to the way that the sounding board functions in a piano.

Being a predominately metal device, rather than a predominately plastic device like a Model M, gives an F the feeling of solidity that makes the act of typing on it seem easier, as well as the fact that testing generally reveals that 10%-15% less force is required.

Last, if you find the noise and overtones annoying, as I do, a floss mod makes a tremendous difference, whereas in a Model M the effects of a floss mod are minimal.

[andrea-i]

my personal experience with both has been as follows:
- tactility of the F is by far superior, I think very few people in the known universe would tell you otherwise.
Actuation smoother than the M and the weighting needed to actuate capacitors allow for the springs to be less stiff than those of the M.
- sound, that's one of the main issues for me, I love the thock sound of my M and I was going insane at some point with the high pitch of the F. Even after a floss-mod to remove the metallic ping, the sound of the little black hammers on the pcb was kind of annoying for me after a while.
- F layouts, the other big issue for me. For as much as I tinkered with the XT layout, I couldn't get adjusted to it in any configuration, same goes for the AT, I just need two modifiers next to the spacebar, period.
Problem solved if you invest on a new kishsaver.

So, yes, I'm the weirdo around here who loves his M and got rid of his F : )

[fohat]

I just need two modifiers next to the spacebar, period.

Adding Alt keys to the AT is not a trivial mod, but it can be done with a few minutes of Dremel work.

[Hypersphere]

It is difficult for me to separate the sound from the feel of a keyboard. For me, I much prefer the sound and feel of my IBM XT to my full-size Model M and my SSK. It has been a while since I have used my M or SSK, but my recollection is that while they have pronounced tactility, they feel scratchy. In contrast, the XT feels crisper and smoother than the M or SSK.

Because of my liking for Model F switches and the 60% form factor, I have ordered an F62 from Ellipse. Of course, I have not had the opportunity to try the F62 as yet, but I anticipate that I might not like the sound and feel of the F62 as much as I enjoy these attributes in my XT because of the respective designs of the cases in the two keyboards. However, I am sure that I will enjoy the form factor and layout of the F62 more than these features in my XT.

[wobbled]

a tightly bolt modded Model M feels just as good to me, though it's all down to personal preference. I've always liked Model M's more.

[Muirium]

I like this thread, as I happen to have all the following boards:

• Model M SSK in good condition
• Model M SSK in need of a bold mod
• Model M122 which I bolt modded a few years ago and did up real tight
• Model F XT in good condition (my very first mech)
• Model F AT I modded (need to post a full layout picture sometime)
• And an original gangster Kishsaver in good condition with a modded HHKB layout

It’s like you asked this question, and people joined in with their own points, just for me!

So, to the answers…

I know very well the sound difference between capacitive and membrane buckling spring switches.
i own a model m keyboard and i have watched a lot of videos for sound comparison.

Careful now! A video—even a Chyros video—can only tell you so much. There’s a lot more going on between Models F and M than just the cacophony you’ll hear on one and not the other.

but i would like to know the difference in tactility between these switches:
clickyness , stiffness, weight, linearity level .. every thing that make any differences in the typing experience (except the sound)

The principal difference between the feel of the two is sharpness. Model F buckles in a really crisp, damn well sharp feeling, that Model M doesn’t have. How much of this is physical—through your fingers—and how much of this is psychological—in your mind’s eye—is more subtle to say. Certainly the heavy metal cases some Model Fs have, like my Kishsaver, well and truly highlight this tack sharp click. The tidal wave of sound helps, too. All those neighbouring springs ringing in sympathy, like adjacent strings in a piano.

Having several Ms and several Fs helps for judging how different each of them can be. Model F is generally lighter than Model M, but my AT is a heavy feeling board and I find it more tiring than my SSKs. Perhaps I should replace the springs? Maybe I did it up too tight? I’ve no idea, but something I can say is it’s also the most plastic of my Fs: it feels the cheapest built, and maybe it’s that clearly just-as-plastic-as-an-M case that alters my judgement of its feel? Could be. I’m a man, damn it, not a pressure gauge!

“Linearity” is an interesting word to use in the context of such defiantly clicky switches! What’s linear about a literally *buckling* spring? But my read on what you mean is how linear is the pre-click portion of key travel? I haven’t thought about it while typing on them—I’m away from home just now, on my HHKB—but from memory I’d say the Fs have it all over the Ms in that regard as well. Could be wrong though. One to try in person.

Something I really like about F is the bottoming out feel, after the click. They are more solid than M, all the way down, because they are just so much more solid built. The Kishsaver is a slab.

So my summary answer is that the mechanism—specifically the big Model F flipper vs. the little Model M hammer—makes a difference, I’m sure, but what I feel the most clearly of all is the difference in case construction. The more solid and the more metal the keyboard, the better you’ll feel those buckling springs, of both kinds.

a tightly bolt modded Model M feels just as good to me, though it's all down to personal preference. I've always liked Model M's more.

I pulled out my bolt modded 122 key recently, and I can vouch this is partially true for me, too. A good tightly wound Model M can approach a Model F in feel. The battleship’s just too damn big for daily use—I modded it years ago, before I had SSKs let alone a Kishsaver to play with—but because I bolted the bugger with extreme prejudice, it well and truly feels like its naval nickname suggests. The case still lets it down compared to a solid Model F, but a bolt mod can indeed work wonders.

[Hypersphere]

I just need two modifiers next to the spacebar, period.

Adding Alt keys to the AT is not a trivial mod, but it can be done with a few minutes of Dremel work.

My solution to this problem was to use a Soarer's converter to remap F10 and NumPad Zero as modifiers.

A tougher problem for me was the Backspace and Return keys. I tried various remappings and keycap swaps on the XT, but I had a more difficult time with the AT. I like to do things HHKB-style, and the reverse-L Return key on the AT blocked my preferred location for Backspace -- where the Backslash normally sits on a US ANSI-layout board. Doing a US ANSI-mod on the AT has been on my to-do list for a long time, but my F62 will probably arrive before I get around to it.

Back to tactility, here are the force-displacement curves produced by HaaTa for IBM membrane buckling spring and IBM F-AT switches:

IBM_M.png (58.14 KiB) Viewed 6195 times

IBM_FAT.png (57.24 KiB) Viewed 6195 times

According to these plots, the total energy (area under each blue curve) and the actuation force are somewhat higher for the F-AT than for the Model M. In addition, the actuation event occurs "later" (further along the displacement axis) for the F-AT than for the Model M. However, the overall shapes of the curves are quite similar between the two switch types. In particular, the "buckling event" is reflected by a very sharp drop in force of similar magnitude for both switch types. However, something not illustrated by such curves is the "scratchiness" of a switch. My impression is that the Model M switches feel scratchier than Model F switches. I tend to interpret the relative absence of scratchiness in the Model F switches as enhanced "crispness".

[sh1]

Last year, I switched from a bolt modded M to an F AT as my daily driver. I was suffering some wrist pain at the time, which the M was triggering, but not the F. And I had attributed this to less activation force.

That said, the graph above, and FWIW both appear to take the same amount of stacked nickels before spring collapse cannot be avoided.

Surprising to me...

[Muirium]

Ergonomics is a multidimensional beast. The different keyboard shape could be more of an effect than the specifics of their rather similar key feel. Your fingers aren’t just pistons!

[Chyros]

IMO, very simply put, the F is lighter, crisper, smoother, and louder.

[Wodan]

... lighter, crisper, smoother ...

Meanwhile, Cherry MX Blue are:

[sh1]

The current state of the aforementioned.

[SneakyRobb]

The current state of the aforementioned.

Looks good. I personally find the Big Ass enter keys to bind a lot in the upper area. Yet my F-AT still has it. I don't think the big space bar aside from the annoying method to re-seat it is that bad. I quite like it. The shorter Model M and F122 space bars are much more rattle prone.

If I recall the earliest Model-M style elements that have been found were numpads. They were basically Model-F construction aside from the membrane inside. They had the same front metal plate, the individual barrels and foam. Basically the "F-Sandwhich" which as fohat says is likely to give it the magic. I think those keys would have a very weird feel. All of the Model-F magic, with the weird "thock" added.

[sh1]

The current state of the aforementioned.

Looks good. I personally find the Big Ass enter keys to bind a lot in the upper area. Yet my F-AT still has it. I don't think the big space bar aside from the annoying method to re-seat it is that bad. I quite like it. The shorter Model M and F122 space bars are much more rattle prone.

If I recall the earliest Model-M style elements that have been found were numpads. They were basically Model-F construction aside from the membrane inside. They had the same front metal plate, the individual barrels and foam. Basically the "F-Sandwhich" which as fohat says is likely to give it the magic. I think those keys would have a very weird feel. All of the Model-F magic, with the weird "thock" added.

Thank you. Actually, I hadn't noticed the upper edge of the enter binding until just the other day when I inadvertently pressed there. Sure enough though.

I really like the Big Ass Enter overall...part of the board's personality to me. Space bar too.

[sh1]

-- A little more on this on this holiday weekend here --

The keys are mostly from an early '87 1390131. (The earlier, inkier, keys being a better match to the remaining F AT ones.)

Replaced the function keys with the navigation section after seeing the 5251 in Chryos's wonderful videos and other early boards. It's admittedly just a supplement to the main navigation, but useful. (Function keys now assigned to the numbers with the left upper corner Insert actually being an Fn key.)

Ideally, would prefer the Ctrl key in the original position, but had to move it to the Model M position as it was causing me issues with other boards. This created a false symmetry with where I have the Alt key, which I broke by restoring the original Alt key.

Whereas I was able to enclose my early bolt modded M in an M13 case, I had to paint the F AT to match my system. (However, IBM had painted it so I guess that's ok.)

Generally, I attempted to extend the symmetries consistent with IBM's early designs.

(Connected through a Soarer's Converter. Certainly wonderful that it takes these early boards and makes them fully programmable with NKRO...)

[sh1]

A note of caution -- If you attempt to remove the IBM silver badge, it is possible by applying two 3/32 inch flat screw drivers to get underneath the badge's right side. However, they must be applied straight, flat, in. Do not wiggle the screw drivers in the slightest. The metal is quite soft and it will cause an indentation.

Found this out the hard way on an XT. Went ok on the AT. Still upsetting. Maybe it's better to tape them off for painting. (When I reapplied the badge, I just used double sided tape.)

[__red__]

There's more of a difference in sound and feel between F4704s, XTs, and F122s than most would believe..

[Muirium]

Correct. Uve used 4 Kishsavers, about as many XTs, a couple ATs but never an F122. I’d rank them as best feel and sound in that order, excepting the F122 of course.

I find the AT heavy and a bit dull in sound and feel compared to its tack sharp brothers. But the layout is so much better than XT. Only the Kishsaver beats it on both fronts.

[sh1]

Brought in my "XT" from the other room...kind of an annoying name, because it's from the prior and original PC.

Anyway, maybe the XT is a bit lighter, but both sound and feel great and are very similar. And sometimes the AT as a daily driver just sounds and feels amazing. I don't know if it's something physical like room temperature or the state of my wrists or some subjective aspect.

The AT was NOS and the XT either NOS or a factory refurb. (The case I painted is actually from a used AT. And maybe that one doesn't feel as tight as the NOS...though it's also kind of subjective I guess.)

[Noodle]

As someone who owns both (and uses the Model F on an occasional basis), I honestly can't say I've noticed a significant difference purely in the tactility of the captivate buckling spring mechanism vs the membrane one.

That being said, I'd still say the actual typing feel of a Model F is much better than a Model M (not to shit in the Model M - it still has a superb typing feel by most standards). I think that has more to do with the build quality of the board than the actual operation of the switching mechanism.

I think the graphs Hypersphere posted sum it up perfectly. You can clearly see that the tactile drop on both is about the same, but the F's force curve is much more uniform and smooth. That lack of inconsistency gives a tauter, smoother, and overall more refined feel that brings out the tactility more.