Will these parts work together?

• Will these parts work together?
  • Keycaps
    • Kitting
    • North facing keycap interference
      • Key switches that mitigate north-facing interference
  • Switches
    • When SMD Switches are required
    • 3-pin vs 5-pin switches and PCBs
  • Stabilizers
  • PCB with case
  • Hotswap

Keycaps

Kitting

Please consult this section on if your keycaps will work with the board you want to put them on.

North facing keycap interference

Many cheaper budget boards/prebuilts will have “north facing” switches. To make sense of this statement, imagine the platform of a switch on the PCB like a compass, where the arrow of the compass faces towards the LED, or where the LED would be facing.

By Cherry spec, PCBs should should have switches face “south”. However, manufacturers will deviate from this specification and make them face the opposite direction so that light from an LED will shine through a translucent legend on the keycap and create an impressive effect when illuminated. These manufacturers work around any possible issues by using a keycap profile that has greater depth (such as OEM or ASA) than Cherry profile to mitigate any possibility that the keycap will impact the top housing.

Here is a brief description of the issue: the south end of a Cherry profile cap does not have much depth, and while on a south facing board it does not matter because the top housing drops off at a similar angle at that point, on a north facing board, there is more room needed by the top housing for the bend of the leaf, and that extra occupied space may collide with the keycap when being pressed down.

Pictured: Diagram provided by milo depicting where a keycap may impact with the top housing Top: South facing switch bottoming out successfully Bottom: North facing switch colliding with top housing.

If you are buying Cherry profile keycaps, and your PCB has switches that face “north”, there is a non-zero chance that your keycaps will be impacted. These manufacturers are known to make keycaps thick enough to collide with the top housing of a switch on bottom-out.

Moreover, if you buy cheaper PBT caps, there’s a decent chance you’ll receive caps that are thin enough to avoid this interference. Similarly, most other profiles (KAT, MT3, SA, ASA, etc.) will not impact the top housings of a switch.

¹: ePBT ABS molds are strange, and are also known to collide with the top housings on boards with south facing switches in some situations.

Key switches that mitigate north-facing interference

There are some switches that may prevent north facing interference by not bottoming out all the way.

Kailh Box ARTs are the only switch I know that use the advantage of the box leaf placement to mold the top housing away from where north facing interference would occur.

Otherwise, you may hear suggestions for switches that do not travel a full 4 mm. These include switches like

• Boba U4Ts/LTs
• Gateron “Box” (Dustproof) Ink
• Akko Radiant Red
• Infinitykey Cow
• Durock POM

These suggestions need to be also taken with a grain of salt, as long pole switches have issues with stabilizers for the following reason: if a switch cannot bottom out to the full 4mm, then a stabilizer stem will not be inserted all the way into the keycap. Moreover, the amount of reduced travel may be insufficient to prevent the keycap-top housing impact.

Switches

When SMD Switches are required

Jankier PCBs (read: not many, just the ones that are cheaply produced) that advertise LED lighting for their switches, instead of cutting a hole for each switch in the PCB and having the LED rest inside of the hole, they will solder the LED on top of the LED. Therefore, switches that have bottoms that are flush against the PCB (barring the legs) will collide with the LED, like those in this screenshot here

In this unlikely situation (most decent PCBs you find will not be like this), you’ll need switches that are “SMD compatible”. The following are generally known to provide the appropriate space in the bottom housing such LEDs.

• Gateron clear-tops (such as KS9)
• Outemu
• TTC
• Most Kailh stuff
• Some Tecsee switches
  • Not Neapolitans

Switches that are not SMD compatible can be identified by not having the large rectangular cutout for the LED, but instead having 2-4 thin holes instead for the legs of a throughhole LED. Switches that would not be SMD compatible may be included (but not limited to)

• JWK/JWICK 4-pin top switches
• Cherry nylon-tops
• SP-Star
• Most Gateron stuff

3-pin vs 5-pin switches and PCBs

This information should be relatively obvious, but for some, it may not be.

Stabilizers

Use your eyes and brain to see if your case takes plate-mount stabilizers or PCB-mount stabilizers. Feel free to consult the pictures at the Stabilizers section for a visual guide.

PCB with case

With a computer build, you just need to know if your case accepts ATX/ITX/mATX motherboards, as well as the maximum number of slots for your GPU that the case can handle. This is not the case for keyboards; keyboard PCBs and cases are not interoperable in the same way that computer parts are, with a few specific exceptions where things have been standardized. Here some of the extremely rare exceptions where there is some interoperability.

• 60%
  • The GH60 layout is possibly the biggest standardized layout the hobby has - this is not a switch layout, this is a tray mount mount-point layout. So generally, any PCB (such as YD60MQ, MJ6, DZ60, FB60, Instant60, BM60*, XD64) that mentions GH60 compatability will mount properly into a case that GH60/DZ60/BM60 layout compatability in (such as, but not limited to) Tofu60, PSD60, etc. Likewise, you could throw a DZ60/etc. PCB into a Brutal60 since they have an identical USB port location.
  • Ducky One boards and Skyloong GK6*X (GK61X, GK64X) have partial compatability with the tray mount points - some of the mount points are shared, some are not. But, they’ll mount alright.
  • PCB’s like those from the RK61 or Gamakay K61 will not fit. The USB port placement on these boards (center and center-right respectively) do not match the GH60 USB port placement between the Esc and 1 key.
• 65%
  • The MW65 (a taobao board) is known to be compatible with KBD67 MKII PCB’s.
  • There are a few 65% PCB’s and tray mount cases that appear to be a GH60-compatible PCB extended out an extra column. These may look like they would be inter-compatible - they’re not! AliExpress reviews for the plastic 65% tray mount case that JKDK sells doesn’t actually work with the Tofu65 pcb, only with the JKDK pcb, as the mount points are slightly off.
• 75%
  • The YMD75/YMDK 75/YMDK84 (whichever isn’t split) PCB has the same holes for tray mount points that the KBD75 PCB has.
• TKL
  • Some more expensive customs/kustoms have a semi-standardized PCB layout with a generally standardized bezel width and USB port placement. Some (included, but not limited to) are (Hiney) H87C, Fave87C, Infinity87, Infinity87.5, Equalz B87C, Suo87C, Snowpro87C, or for F13 TKLs, H88C, Infinity87.5, Jels88.
  • Some PCB and case compatability is documented here

Hotswap

Beyond the earlier mentions of how 5 pin switches will not fit in a 3 pin pcb, hotswap sockets are generally not limited in what switches they would accept, with the exception of Outemu hotswap rivets. (Note: these look like regular solder joints, and are obviously distinct from the surface mount Outemu hotswap socket that resembles Kailh/Gateron/TTC/CIY sockets).

Outemu hotswap is limited to Outemu switches (as of 2023, this no longer includes Gazzew Boba switches), as the pins for the switches are sufficiently thin enough to enter the socket without sanding. Other switches that may fit in include

• KTT
  • Akko CS switches are included in this classification
  • May require elbow grease to fit
• Tecsee [?]
  • This is based off of some report that Glorious Holy Pandas fit into a Rakk Ilis without issue. Since the manufacturer is generally implied to be Tecsee, other Tecsee switches may fit.
• Huano
  • Kind of hear-say from Reddit.