KeyMouse Track 300 Series Assembly Instructions

(Updated 06/02/2022)



Parts to 3D Print per Hand

To access the STL files to 3D print the parts needed, fill out the KeyMouse Maker Program Agreement, and email it to This email address is being protected from spambots. You need JavaScript enabled to view it. and we will get back to you with the requested STL files.

Note: Make sure to double quantities if assembling both hands

1 x Top Housing
  1 x Bottom Housing
  1 x Trackball Holder
        1 x “Post” Button
  5 x Adjustable Feet (various heights available for leveling device)


If 3D printing your own housings, please refer to notes below:
A build volume of at least 225mm x 225mm is required (refer to spec sheet for dimensions)
To print using ABS filament (recommended), 3D printer must be enclosed to retain heat. A heated bed is also necessary for ABS.
For best print quality, print with 0.4mm nozzle and 0.15mm layer height.
The amount of 1.75mm filament used in grams for each part is:
Top Housing - 260g
Bottom Housing - 159g
Trackball Holder - 6g
Trackball Removal Tool - 4g
Adjustable Feet - 5g (approx. for 5 feet)


Parts to Purchase per Hand

Note: Make sure to double quantities if assembling both hands

  1 x  Main PCB Module 3.0T
  1 x Mouse Sensor Module 3.0T
  7 x Cherry Key Modules with punch-down (5 pack)  
  1 x Complete Key Cap Set (Note, you will only need to purchase this once per set)
8 x Blue Small Button Modules (for F Keys)
3 x Black Small Button Modules (for Mouse Clicks)
  1 x Small Button Cap Set (Note, you will only need to purchase this once per set)
  1 x Red Wire for punch-downs (10 pack) (Note, you will only need to purchase this once per set)
1 x Blue Wire for punch-downs (10 pack)
2 x Backlight Wire for punch-downs (2 pack)
  1 x 25.8mm Trackball
  1 x Rubber Feet (Note, you will only need to purchase this once per set)
1 x 2mm Ceramic Balls for Trackball (3 pack)

1 x Screw Pack For KeyMouse Track - One Hand

1 x Punch-Down Tool Bit (not necessary if you already have 28 gauge wire punch-down)



General Notes Before Starting

1. Do not plug in the Main PCB Module to the computer until all components are in place and securely fastened. The Main PCB will be damaged if short circuited.
2. The example images are using Right Hand KeyMouse Track. Apply the same steps for left hand (with a few exceptions...we will show instructions if left hand is different).
3. When installing screws, you will need to gently tighten them so they don’t strip the 3D-printed plastic.
4. There are tight tolerances, so keep all wires and everything as tidy as possible to ensure housings can close properly when assembly is done.
5. Tools needed: small Phillips screwdriver and a 28 gauge wire punch-down tool

How to Assemble Your KeyMouse

1. 3D Printed KeyMouse Track parts for Assembly

2. Main PCB - Starting with the Bottom Housing, place the Main PCB inside, aligning holes with mounting bosses. Secure using 4mm screws.



3. “Post” Button - Snap the “post” onto a black small button module, and insert into the “post” button hole. Make sure the “Col” lettering is on the top. Secure using 6mm screws.



4. F Keys & Thumb Keys - Snap the F7-F12 (F1-F6 on Left Hand) button caps onto six of the blue Small Button Modules, so the lettering “S1” is at the bottom, as shown in the picture. Then, face the Top Housing upside down and insert the six Small Button Modules (make sure the “Col” lettering is on the top on all six), then secure using 6mm screws. Snap the blank button caps onto 2 of the blue small button modules. Insert switches into the two small button holes below the F keys.



5. Mouse Buttons - Snap the mouse (or blank) button caps onto 2 of the black small button modules, again, so the lettering “S1” is at the bottom, as shown in the picture. Insert switches into the two on the back of the palm rest by the trackball holder. Make sure the “Col” lettering is on the top. Secure them using the 6mm screws.




6. Snap Cherry Key Modules in Top Housing - using your thumb, press each Cherry Key Module into the top housing. Make sure the LED is on the top side (toward the back of the device). When pressing them in, they should make a “snap” sound when they are all the way in.




7. Punch down wires - Important: Hold in the Cherry Keys from the opposite side as you are punching the wire down. You can do this with either your hand or with our 3d printed jig. If you fail to do so, the Cherry Keys WILL pop out and rip the wire. You MUST connect “Rows” to the Row pins, and “Columns” to the Column pins on the Main PCB 3.0T, or the keys will not work. Each key has a diode to prevent “ghosting”. (Note: for the “Post” button, it is on its own on Column 9.) Using the punch-down tool, punch wires closest to Main PCB outwards leaving a little bit of slack between each key.





8. Rows Complete - 5 red wires and 1 yellow/green wire



9. Columns Complete - 10 blue wires


10. Rows & Columns Wiring Complete




11. Backlight (+) complete - 1 green wire



12. Backlight (-) complete - 1 yellow wire



13. Trackball Holder & Mouse Sensor - Press in the 3 white ceramic balls into the Trackball holder. Align the mouse sensor onto the right trackball holder (labeled “R” for right hand) and secure using 6mm screws. Make sure the sensor is aligned correctly with the hole where the trackball will be. Then secure the trackball holder to the top housing with 6mm screws. If the mouse sensor is aligned correctly, the pins on the mouse sensor will point away from the housing.




14. Connect Mouse Sensor Module to Main PCB - using the white 7 Pin Connector cable, connect the Mouse Sensor (trackball module) to the Main PCB. Be sure to use the correct orientation of the cable.



15. Double Check Connections - Make sure all connections on the Main PCB 3.0T are tight.

16. Test - Before closing the housing together, you may want to test all of the keys to make sure they work. You can download the software at:
Once the software is downloaded, you will also need to assign what type of devices they are. To do that, open the software, and under the “Devices” tab, click “Firmware Update”. There should not be any devices listed. Connect one device to your computer (not both, just one). Then click the “Advanced” tab and on the top right, you can see from the dropdown what device type and which hand you can assign to it. Select the appropriate options, check the box by the device in the list of devices (should only be the one) then click “Save to Device”. Do the same for the other hand. Then assign your key layouts to the devices and test.


17. Screw Top & Bottom Housing Together - After making sure all wire connections are secure, very carefully make sure all the wires are inside the housings where they won’t get pinched between the housings or between the screw mounting bosses. Try to keep the wires as tidy as possible. Close the top and bottom housings together and secure from the bottom side using 10mm screws.


18. Adjustable Feet - Align the adjustable feet in the designated holes on the bottom housing and press them in with your thumb (you may have to try different sizes to make sure the device sits flat and does not rock on the desk). Once the device is level and you have the desired sizes in, secure with 6mm screws.




19. Rubber Feet - Place the rubber feet stickers centered on each of the adjustable feet.



20. Key Caps - Flip the device over, and put key caps on the Cherry switches. Make sure to press them firmly in with your thumb.




21. Trackball - Insert trackball into trackball holder. With a little pressure, it should pop in.


22. Left Hand - Repeat steps 1-21 for the Left Hand.


All Done! Enjoy Your KeyMouse Set!