Page 3 - A Closer Look - Disassembly and Internals
As part of our disassembly, we can start by first inspecting the keycaps. These are PBT or polybutylene terephthalate plastic with a double-shot injection. I like PBT as a material choice, as it is more durable and do not shine or fade over time compared to other commonly used plastics like ABS. The thicker wall also adds to a deeper sound when used. The legends are inserted with a second layer of plastic, which is why it is called double shot. This is why you see a white outer shell and a translucent inner plastic. As such, the legends will not fade or wear over time, but it is a costly option for making keycaps. The choice of font is clear and legible with OEM-like writing. The keycaps use standard MX stems with a Cherry profile. The Epomaker HE108 offers full NKRO over USB. NKRO stands for N-key rollover, which refers to the number of keys scanned independently by the hardware.
The longer keys of the Epomaker HE108, like the space bar and Enter, have Cherry stabilizers on each side to ensure an even actuation and to prevent wobbling. These are factory lubricated as it has a smooth travel and do not rattle or squeak when the longer keys are pressed. The stabilizers are plate-mounted rather than screwed into the PCB. This is usually a cheaper alternative, as plate-mounted stabilizers can cause a bit more rattling. Thankfully, the stabilizers do not make much noise. The plate is polycarbonate and flexes easily under pressure. There are flex cuts in both the plate and the PCB board underneath. This affects how each keystroke sounds and feels.
One of the key selling points of the Epomaker HE108 is its switch technology. Hall effect switches are still made similar to mechanical switches as it consists of a housing base, stem, and spring, offering varying levels of tactile and audible feedback. For Hall effect switches, these have a small magnet at the bottom of the stem, and the magnetic field is detected by a sensor on the keyboard to detect key presses. More specifically, these are Epomaker Creamy Jade HE Hall effect switches. They are linear in travel and require a bottoming out force of 55g, and a configurable actuation point from 0.1mm to 3.3mm in 0.005mm intervals, and total travel of 3.3mm. These connect to the PCB with hot swap sockets, but there is no electrical connection between the switch and the PCB. The sockets support two-pin sockets for Hall effect switches. As such, if you do not like these or an individual one fails, you can swap it out without replacing the entire keyboard, but you can only put in other Hall effect switches.
Taking a closer look at the Epomaker Creamy Jade HE switch, it has a blue top and light teal bottom. A stem is in the middle with a 20mm spring that keeps the switch elevated. The switch stem has minimal lateral movement inside the housing, which ensures actuation is stable and the keys do not wobble about. The switches are factory lubricated for a smoother typing feel and sound, and you can see some excess lubricant on the spring. The stem is made of POM plastic. The upper case is polycarbonate, while the bottom one is PA66, which refers to polyamide or nylon 66. A thin translucent acrylic light diffuser is located on the south side of the switch.
Taking apart the Epomaker HE108 is a bit more involved due to the use of plastic clips holding everything together. With some pry tools, I was able to expand a small gap at the back corner of the keyboard and work my way around. You will also need a small hex key or screwdriver to take the back blue plate off before you can detach everything. This plate holds the back two toggle switches in place. Once the clips are released, the top and bottom separate from each other. The keyboard portion is held to the bottom daughterboard with a ribbon cable.
The keyboard deck sits in here with gasket mounts in between the top and bottom shell. There are eight protrusions around the deck with rubber mounts to hold in place. These gaskets should also reduce vibration or unwanted movement transferring from the deck to the rest of the enclosure. Underneath the deck, there is a thick layer of silicone to fill in the gaps of the bottom shell. It also works as an insulator for the two 5000mAh batteries underneath and the daughterboard. The two batteries add up to 10000mAh, which ensures a long battery life. I am happy to see the USB connection and switches on a separate daughterboard, as this ensures the fixed components like the USB port is isolated from movement on the keyboard deck, reducing the stress that the port may otherwise endure.
In between the plate and the PCB, there are several layers of sound damping material, including a Poron sandwich foam, IXPE switch pad, and a sound-enhancing PET layer. Under the printed circuit board, there is another layer of PORON and latex switch socket foam and the aforementioned silicone padding. All these layers contribute to the overall typing sound and feel. Underneath the sides of the PCB, there is a column of LED lights, which produce a nice side glow on the Epomaker HE108.
Page Index
1. Introduction, Packaging, Specifications
2. A Closer Look - Hardware and Software
3. A Closer Look - Disassembly and Internals
4. Conclusion
