How Does One Measure Key Caps to Determine Dimensions?

[aref]

1. How does one measure a key cap to determine its size?
2. What unit measure for key-cap dimensions?
3. Finally, where on a key cap does one take a key-cap measurement? (I would think the outer perimeter at the base with respect to a keyboard's spatial relationship re key-cap fit.)

I looked under GH Wiki and searched the web... squat, zilch, nada. rien, nichts.
If you can help, I'd appreciate it. Thank you, GH.

[Pacifist]

relative to a 1 unit alpha key is usually how its done

apart from that the bottom part of the key for technical measurements

[HPE1000]

? Kinda confused here.

From my understanding, this is how it goes.

1 is just your standard size key for a single switch, something like the letters and numbers on a keyboard.
1.25 is the size of one and a quarter 1 unit keys, this is for keys like window, ctrl, alt, menu, fn, etc on a standard winkey keyboard.
1.5 is the size of 1 and a half 1 unit keys is for ctrl, alt, etc for a winkeyless keyboard.

And so on, same goes for spacebars and shift keys and everything.

[aref]

relative to a 1 unit alpha key is usually how its done

I figured that. The closest I can get to an actual measurement is 18mm in X and Y dimensions for a single unit alpha key, taking base measurements.

[aref]

If one wants to order an oddly sized key cap and has to order a specific size, the standard unit of measure is, mm?

[Pacifist]

If one wants to order an oddly sized key cap and has to order a specific size, the standard unit of measure is, mm?

nobody does mm

even when sp sells stuff in the warehouse its in 6.25x, 7x, 2x, 3x, 4.5x etc

[tbc]

1x, 1.25x, etc

no one uses actual measurements.  the retailers/manufacturers will understand what you mean.


unless you're trying to make a truly custom width cap instead of trying to replace an existing cap?

[aref]

1x, 1.25x, etc

no one uses actual measurements.  the retailers/manufacturers will understand what you mean.


unless you're trying to make a truly custom width cap instead of trying to replace an existing cap?

You nailed it! In ordering a custom-width key cap, how does one express the unit of measure?

[tbc]

are you trying to get one 3d printed?

if so, use w/e measurements the printer needs.


if you're trying to get a keycap manufacturer to make one for you (PIM), then you'll need to pay for a new mold and there should be someone at the company working with you for up to several weeks and 3000+ dollars depending on complexity and errors.

if you're talking to an artisan, just ask them what they want.

[Pacifist]

1x, 1.25x, etc

no one uses actual measurements.  the retailers/manufacturers will understand what you mean.


unless you're trying to make a truly custom width cap instead of trying to replace an existing cap?

You nailed it! In ordering a custom-width key cap, how does one express the unit of measure?

You can't really simply order a key of a specific width...but if you want to get a key produced from scratch, you'd probally either need a master or a 3D image of said key, all of which can be measured in whatever you want it to be

[CPTBadAss]

This link may help you OP

[aref]

This link may help you OP

CAPTBadAss: Thank you. My standard metric ruler measurement came out out a tad less than damorgue's, about 18mm for a 1x1 cap.
According to GH member 'damorgue' "...a Unit by Cherry...is 19.05mm. 2.25u is the same as 2.25*19.05mm"

This tells me I'm on the right track. The key caps' and ratios fit this measurement, albeit lacking in dead-on accuracy. Nonetheless, it's pretty close.

According to Jacobolus, "...For instance, SP 1x keycaps are 0.725" (18.42 mm) wide..." This is more in line with my measurement with a common metric ruler.

[Photekq]

19.05 isn't the size of a 1 unit cap.

19.05 is the distance between the centres of two MX switches with 1u keycaps on them that are next to each other.

[aref]

19.05 isn't the size of a 1 unit cap.

19.05 is the distance between the centres of two MX switches with 1u keycaps on them that are next to each other.

Your're right. I had to change the info. I measured 18.xx for the width of a 1x cap. But my measuring device is not accurate--it's a simple plastic ruler.

[Broadmonkey]

A keycap IS 18mm not the 19.05. This is because there has to be space between the keycaps.

[aref]

Thanks, GH.