There are many good sites full of information, how to build your own keyboard. In this wiki you can find a lot of links and most important information only.
It is strongly advised to check at least some of these blog posts and articles.
- Build Your Own Mechanical Keyboard Project: What you need to get started
- How to Build a Custom Keyboard With Mechanical Switches: A Complete Guide
- How I Built My Own Keyboard
- Building your own keyboard (from scratch)
- How to Build a Custom Mechanical Keyboard Gamepad
The first thing before ordering any components or start building, is to decide what should it look like. There are separate components or kits available for most popular layouts. Building everything form scratch could be expensive and is usually time consuming but then there is no limits on what it will be. Still, it is suggested to build at least one keyboard using details from professional manufactures before jumping to fully custom handmade setup.
Here is a very good guide of all common layouts.
You can easily try out different layouts using keyboard-layout-editor. In case of standard layouts, make sure which one you like to use, ANSI (US) or ISO (Europe).
Switches are most important part of the keyboard. There are no right or wrong switches. A lot depends on personal preferences and the keyboard use (for example gamers vs typists).
Switches can be divided into three main category:
In every category there can be also "silent switches" and switches with different actuation distance (1.2 mm - 2.2 mm), travel distance (up to 4.0 mm) and actuation force (45 cN - 60 cN). For instance Cherry MX Red is 2 mm and 45 cN while Cherry MX Blue is 2.2 mm and 55 cN. The heaviest of Cherry's linear MX is Linear Grey MX with actuation force of 80 cN!
There are many brands to choose between. Here are some most popular switches with Cherry MX stem (compatible with Cherry MX keycaps).
It is highly recommended to try different switches using a switch tester before ordering hundreds of switches.
Keycaps can have very different profiles. Usually the profile also depends on the row but there are some profiles where all rows are equal. For some more information, click here.
Keycaps could be made of different plastics, usually ABS or PBT. Symbols could be "molded in" (doubleshot), pad printed or laser engraved or dye sublimated. Here are great photos of double shot keys compared with other "print" methods.
Cherry MX keycap widths use units of 19.05mm or 0.75" and are between 1x (square) and 7x (long spacebar - look at this wiki page) in 0.25x increments.
Make sure that all sizes are correct and Enter key is right one (ANSI or ISO).
Here you can find tons of links and information about keycaps.