Zaunkoenig M2K PCB

STEP file for the PCB of the Zaunkoenig M2K. This file is not intended to be printed out. It is intended to help you design a gaming mouse shell for the M2K PCB.

A few notes about the screws used for the M2K PCB:

• We use two T6 M2 screws at the front left and right (those are used for the height adjustment functionality of the M2K PCB).

• We use three T6 M2 screws to screw the M2K bottom shell into the M2K carbon fiber shell. 

• We use two T4 M2 screws to screw the M2K PCB onto the M2K bottom shell.

• See this M2K disassembly video by BeardedBob for more information.

A note about the distance between the sensor and your tracking surface (your mouse pad):

PixArt in the 3360 data sheet recommends a «Distance from Lens Reference Plane to Tracking Surface» of at least 2.2 mm, 2.6 mm at most with the typical value being 2.4 mm.

Weight overview:

• M3K PCB (including lens): 6.8 grams

• M3K wheel: 0.9 grams

• All seven screws: 1.1 grams

A few notes about the cable setup we use for the M2K PCB (identical to the M1K PCB):

• Pinout: The black conductor (ground) should be inserted into the Molex receptacle so that it is the one closest to the sensor, followed by yellow (D+), white (D-) and red (5 Volt).

• The M2K cable has a diameter of 2.5 mm ±0.15 mm.

• Crimps: The little golden thingies that are on the end of each of the four conductors are called crimps. The ones on the M2K cable are made by Molex and are from their Pico-Lock product family (MPN: 5040520298).

• Crimp receptacle: The black plastic part that you insert the four crimped wires into (MPN: 5040510401).

• PCB header: This is the part that you insert the crimp receptacle into. This part is soldered onto the M2K PCB, so normally you do not need buy it for a mod with the M2K PCB (MPN: 5040500491).

• Crimping tool: The official crimping tool for the above crimps costs $540, which is pretty expensive (MPN: 0638270900). If you only want to crimp one cable it is not worth it spending that much. Instead just get the Engineer PA-09 or the PA-11 (see this article for a comparison of both).

• If you want to use a different cable see this guide by kyleirelandtech on how to install an Enncoo AirCord in an M2K; this guide is applicable to the M3K as well.

A few notes about the modding capabilities of the M2K PCB:

You can modify the M2K PCB either by modifying the open-source firmware of the M2K or by using the various modding pads (a small golden circle with a hole in it, so you can easily solder a wire to it) on the M2K PCB.

Note that the M2K PCB actually consists of two separate PCBs. The wheel encoder and middle mouse button switch sit on a separate PCB that can be connected to the main PCB with a so-called Board-to-Board connector (Molex SlimStack).

The following screenshot shows the twelve modding pads in the bottom left corner of the M2K PCB (see the golden circles on the bottom left), as well as the six modding pads on the bottom right side of the M2K PCB (see the blue rectangles; these six modding pads are on the backside of the M2K PCB and they are needed for flashing firmware on an M2K MCU with no previous firmware on it, so you probably will never need them anyway):

Note: On M2K PCBs with a serial number between 0001 and 0100 the four modding pads in the middle are exchanged; instead of GND, PA14, PA13, VDDA they thus are VDDA, PA13, PA14 and GND.

In the middle of the M2K PCB we have broken out MOSI, SCLK and MISO (SPI) as well as the wheel (WH+, WH-) and the middle mouse button (MMB and ~MMB):

The wheel and middle mouse button are broken out on the daughter PCB as well: