Bell Disassembly
Start by pulling out the actuator from the tip of the bell.
Then, pull out the collar from the bell.
Lastly, pull out the base from the bell.
Set the plastic parts aside, they won't be used in this project.
Secure PCBs
Gather up the hardware screws needed to secure the two PCBs to the 3D printed bottom cover.
Place the Feather over the standoffs with the USB A port fitted over the tab. Insert and fasten M2.5 x 6mm long screws to secure the PCB.
Place the solenoid driver over the remaining standoffs with the orientation matching the assembly photo. Insert and fasten M2.5 x 6mm long screws to secure the PCB.
PCBs Secured
Double check the PCBs are fully secured to the 3D printed bottom cover in the correct orientation.
Top Cover Solenoid Mounting Plate
Gather up the 3D printed top cover and bell mounting plate.
Orient the two parts together so the mounting holes are lined up.
Join the two parts together using two M2.5 x 6mm long machine screws.
Assembled Top Cover
Take a moment to ensure the top cover and bell mounting plate are secured correctly.
Screw Tap Solenoids
Use a M2 size screw tap to create threads in the mounting holes on the two solenoids.
Be careful not to screw too far in and damage the wire core.
Secure Solenoid Bell Ringer
Fit the JST-PH connector from one of the solenoids through the square hole on the top cover assembly.
Orient the mounting holes on the solenoid with the holes on the 3D printed mounting plate.
Insert and fasten two M2 x 6mm long machine screws to secure the solenoid.
Test Solenoid
Ensure the solenoid is secured and mounted to the 3D printed part correctly. Push on the plunger to ensure its pushing in the correct orientation.
Secure Typing Solenoid
Gather up the 3D printed case, M2 screws, and solenoid.
Place the solenoid inside the 3D printed case with the mounting holes lined up.
Insert and fasten two M2 x 6mm long machine screws to secure the solenoid.
Snap Bottom Cover
Get the bottom cover and the case ready to join together.
Orient the bottom cover with the case so the USB A port from the Feather is lined up with the USB cutout on the case.
Firmly press the two parts to snap fit them together.
Ensure the wires are not pinched or kinked.
Connect Cables
Grab the JST cable from the solenoid inside the case and connect it to the JST cable that is connected to the 0 pin on the solenoid driver.
Connect the remaining JST cable to the solenoid that is secured to the top cover mounting plate.
Snap Top
Orient the top cover with the case so it matches the assembly photo. Firmly press the top onto the case so the two parts snap fit together.
Ensure none of the wires are pinched or kinked.
Install Bell
Place the bell over the post on the top cover.
Press the 3D printed top pin into the post until its fully seated.
Install Keys
Press the 3D printed faux keyboard onto the cavity on the case. Firmly press the edges into the cavity so it snap fits.
Connect USB Keyboard
Plug in the USB cable from the keyboard to the USB A port on the Feather RP2040.
Plug in the USB-C cable to the USB-C port on the Feather. Then, plug it into your computer or mobile device.
Page last edited June 17, 2025
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