Backward slope in keycaps

[sandywind]

Most keyboards I have owned featured a much pronounced backward slope in the keycaps of the first rows. Since these keyboards also offered retractable feet, I wonder, is there a rationale for the combined design of such slope and the height of the feet? Is it advisable to use such keyboards with closed feet?

Some keyboards like the KBC Poker 2 do not have retractable feet, and keycap slope seems less aggressive, other have feet which level the keycaps when opened, but I can't quite understand how one should use a given keyboard, with feet opened or not, if there is an ergonomically justified principle or it is just a matter of personal preference. Under the hypothesis that wrists are level, obviously.

I guess this question may have been asked many times. I am new to this community and I apologize for asking once again.

 

[Findecanor]

In the beginning most keycaps had spherical surfaces. Then engineers found that it was easier to print on them if the surfaces were cylindrical, so they changed.
My theory is that cylindrical keycaps are sloped to make the front edge more acute - more like that of the spherical keycaps.

[jacobolus]

If your hand starts out on the home row, and your reach back toward your body (via some combination of flexing your finger’s second joint and moving your whole hand) to get to the lower-row key, I find that it’s pretty helpful to have the keycap top angled up to catch your fingertip.

Whether to use the feet or not (or whether to tilt your keyboard to a different angle than the feet support) really depends on the height of your desk and chair. I don’t personally think the keycap top angles should have have much to do with the overall keyboard tilt, though historically they have often been set up so the home row has its top parallel to the ground, something I think is not really necessary.

See this post I just made https://geekhack.org/index.php?topic=66236.msg1552306#msg1552306 about how to set your keyboard to the correct tilt.

[Oobly]

I disagree with jacobolus on the keytop angle. I believe it is important to have a close to horizontal surface on the home row keycaps, with angles on the keycaps on other rows such as to form a continuous curve which matches finger movement. This leads to the least effort and fatigue when typing compared to having ridges you need to lift your finger over when moving to higher / lower rows.

I posted this in the SA profile discussion thread:

"The reasons I consider the less back-angled keycaps to be better is it reduces the finger / hand / arm movements required to move between rows (since you don't have to lift over the ridge) and thus allows more efficient and less fatiguing typing. Particularly when you also add some nice angling of the keycap tops as in sculpted SA. It also provides good finger movement direction when pressing, at least on rows 1 to 4. I do think there could be a hair more difference in height between rows to allow a more continuous curve between keytop angles from row 1 through 4 (with rows 2 and 4 still identical to each other, with mirrored angles), but it is close enough to ideal not to matter much.

It really is the only profile that truly feels "right" for me on a properly angled and positioned board of all the ones I've tried.

Anopther reason I like SA caps is their mass. Row 3 caps weigh 1.95g, more than twice what Row 3 DCS caps weigh (0.78g). It really give a nice feeling when typing, IMHO."

https://geekhack.org/index.php?topic=63052.msg1536871#msg1536871

Most current keycap profiles (Cherry, OEM, DCS, etc) were designed to match existing keytop angles and heights from older boards which had a steeper angle than many modern boards (like typewriters and terminal keyboards, and which were used differently too - higher desk, steeper arm angle, etc).





It's better ergonomically to have a flatter board with lower arms about parallel to the ground and a keyboard angle somewhere between very shallow up angle to very shallow down angle (angled away from you), depending on the keyboard height, etc.

This is why flat laptop "chiclet" keyboards are actually quite okay to type on, despite the lack of contouring. IMHO, the best profile for proper ergonomic posture and desk setup is fully sculptured SA profile.

[jacobolus]

I disagree with jacobolus on the keytop angle.

You’re not disagreeing at all! Our two comments are about totally orthogonal things (in the sense that you could set up a keyboard adopting either piece of advice separately, or both together, or neither). Namely, you’re suggesting the angle of the home row keycaps should be flat relative to the keyboard, and I’m saying someone picking how to tilt their keyboard overall shouldn’t worry about what the keycap angle is.

When you say “horizontal surface” you mean relative to the keyboard (e.g. the PCB, plate), not relative to the table/ground. Whereas what I said is “historically [the keycaps] have often been set up so the home row has its top parallel to the ground, something I think is not really necessary”. You clearly also don’t think it’s necessary, since you’re advocating directly against it.

To the OP: I wouldn’t worry about the keycap angles too much. I think your existing keycaps are fine. If you want you can play around with replacements, and it’s possible you’d find an alternative set that you’d prefer, but it’s by no means necessary. Just tilt the keyboard until your wrists are straight, and you’ll be in pretty good shape. A keyboard with a very steep built-in tilt and no feet is designed to be used on a table that’s high relative to your chair. If you want to type for long periods of time, I’d advocate putting such a keyboard on a lower table and tilting it backward by raising its front side.

[Oobly]

I am disagreeing with you on the keycap angle. You say the keycap angle doesn't matter, I say it does. The home row keycaps should be flat relative to the PCB and flatt-ish relative to the ground (since the board should be either flat or angled just a little either direction, assuming you have also sorted out your desk and chair heights to enable this). We agree on the other aspects of creating an ergonomic setup, though (desk and chair height, arm angles, board angle, etc.). And also we agree that getting the board angle right is more important than the keycap angle, but it does still matter.

My point about the ridges is pertinent and actually quite valuable if you truly want to reduce typing effort and to me it's more important than getting them flat WRT the ground. It does look (and feel) a little weird if you have a steeply angled board with SA profile caps on, but a good ergonomic setup shouldn't be like that anyway.

In my recent experience, after typing on SA caps for a while, Cherry profile GMK caps were more tiring and slower to type on (which was quite a disappointment to me, since they were my new GMK Dolch set).

[jacobolus]

I am disagreeing with you on the keycap angle. You say the keycap angle doesn't matter, I say it does.

I never said that in this thread. You’re putting words in my mouth. What I did say is that I think the OP’s existing keycaps are fine, and rushing out to buy new keycaps of a different profile is not necessary. Plenty of people are perfectly happy with the stock keycaps that come on their keyboards, or other “standard” sculpted cylindrical keycap sets. (But for anyone who wants to replace their keycaps, that’s also fine. There’s quite a bit of subjective personal preference involved in keycap shapes.)

The question the OP asked is whether he can use keycaps designed for a steeply angled keyboard on a keyboard that has been tilted to be flat. To which the answer is: absolutely. Personally I think those keycaps were partly mis-designed: there was no reason other than subjective aesthetic preference to design them such that the home row is parallel to the table/ground. But since the keycaps already exist, using them on keyboards tilted in various ways is fine. The existing keycaps won’t get better or worse by tilting the keyboard.

You’re answering a different question, which while interesting, is not entirely relevant IMO. There are 2–3 other recent threads about the subject of keycap angles, but while we’re talking about it here, this is what I want to see:

Where the purple is DCS, and the black is my desired profile (largish spherical tops would be great, but I think cylindrical tops are also fine). Unfortunately nothing close to that currently exists.

[Oobly]

I guess we agree more than I thought. Standard caps are definitely usable on a flat angled board, but I don't particularly like how they feel after trying a profile based on a "flat" home row and I think they're one reason I initially had difficulty deciding on a keyboard angle in the past. Tilted felt better in terms of keycap top angle, but flatter felt better in terms of finger movement, although I didn't yet know at the time the reasons both felt somehow subtly wrong.

I'd give that profile you're proposing a try if it existed I particularly like that Z-row angle.

[sandywind]

Thank you for replying; your observations are enlightening.

Main main keyboards are a Corsair K65 and a 1984 Model M. I tend to use feet for both keyboards, mainly because finger movements seem more natural and I tend to make fewer mistakes. If I do not use feet, making few mistakes requires a higher level of mental effort. Until a few minutes ago I had not really been able to understand whether it is a personal preference or a feature of these keyboards, or a consequence of my setup and posture. I set up desk and chair to have forearms parallel to the ground and forming a 90 degree angle with my arm. I thought this posture I borrowed from my piano lessons could be correct.

The home row of both keyboards is not parallel to the table when feet aren't used---neither is it when feet are used. It is angled as DCS home row is in jacobulus' figure, in the first case, and it descends slightly towards me in the second case. Revising critically my setup and posture I now believe my elbows are just slightly below the home row, which explains why I prefer to use feet.

Still it is interesting to note that keyboard designers seem to support either a slightly descending or ascending forearm posture, instead of a more neutral choice---which if I understand correctly would be in the spirit of jacobulus' proposed profile. (I think the keycap base in the drawing is not horizontal by only to accomodate row labels and the home row in your proposal is intended to have both a horizontal top and bottom.)

[jacobolus]

I set up desk and chair to have forearms parallel to the ground and forming a 90 degree angle with my arm. I thought this posture I borrowed from my piano lessons could be correct.

Sounds good. In that case I recommend not using the feet. But do whatever you prefer, as long as it’s not causing you discomfort.

Still it is interesting to note that keyboard designers seem to support either a slightly descending or ascending forearm posture, instead of a more neutral choice-

Keyboards are designed with the expectation that most people will use them on too tall a table. Judging from what I see when I visit people’s homes and offices or look at pictures of people’s setups, I’d say that’s a fair assumption.

Though actually that’s probably too generous: more realistically, the folks making keyboards aren’t thinking about this at all, but just buying whatever keycaps they can get for cheapest. The current sculpted keycap profiles are basically trying to copy what IBM and Honeywell did in the 60s–80s, because it’s “standard”. At that time, keyboards were enormous, and often on high desks, and people were used to typing on typewriters, so it made perfect sense to have a steep angle.

which if I understand correctly would be in the spirit of jacobulus' proposed profile. (I think the keycap base in the drawing is not horizontal by only to accomodate row labels and the home row in your proposal is intended to have both a horizontal top and bottom.)

In my drawing the keyboard is angled slightly away, that is, up at the close side / down at the far side. I find the most comfortable angle to be somewhere between flat and about -5°. Note that I use a high saddle-type chair (HÅG Capisco) and an adjustable sit–stand desk.