MB-TKL
Overview
MB-TKL started as nothing more than an exercise in layout experimenation. The goal was to have a 12.75u layout as the main cluster, all 12 F-keys and TKL style navigation and arrow keys. As the layout evolved through several iterations, the idea of creating a case around it became more appealing, and thus MB-TKL was born.
MB-TKL Keyboard Layout
The Layout
Let's get it out of the way. This layout is a bit funky.
The three key essentials for this layout is a 12.75u main cluster, all twelve F-keys and TKL style navigation and arrow keys. TKL navigation and arrow keys are easy. The challenge is having the F-keys, three clusters of four keys, separated evenly within the confines of the 12.75u layout. The 12 F-keys can easily be laid out in three clusters with 0.375u blockers in-between. However, this results in an ortholinear-like layout with the first cluster of four; not my preferred aesthetic. The split in the alphas entirely serves to alleviate this issue, but has the added benefit of providing some ergonomics. Offsetting the F-keys provided the opportunity to add a fun light bar. Tack on navigation and arrows keys, and call it a day!
The left 3U spacebar can be split into 2U + 1U or 1U + 2U configurations. There is also an option for win key (WK) or win-keyless (WKL) which will include a blocker on the case.
Case Construction
The case is a typical three piece construction that consists of an aluminimum top and bottom and brass weight. MB-TKL features the use of a plate that is top mounted.
While the case is intended to be simple, the side profile features a simple compound curve with filleted edges. Adding to the playfulness of the side profile, a diffuser is also included to soften and dispears the LEDs on the top left.
The brass weight&pos;s exterior appearance is that of a simple accent piece, recessed to avoid damage while resting on a desk. Inside the case, the soft brass material encompasses the majority of the interior surface area in an effort to absorb some vibrations.
MB-TKL Case from Factory
MB-TKL PCB Bottom
PCB
The PCB is powered by an Atmel Atmega32u4-AU and features an RGB LED light bar, and split spacebar layouts as shown in the Layout section above. The PCB also includes breakout pins for debugging purposes. This PCB is a very simply design that incorporates ESD and oversurge protection.
Other features such as rotary encoder support has been considered, but have not been implemented due to my own personal use case.
Specifications
| Layout | 40% TKL - 12.75u main cluster |
|---|---|
| Plate Mounting | Top Mount |
| Typing Angle | 6 degrees |
| Front Height | 16.8mm |
| Effective Key Height | 21.6 mm |
| Case Material | 6063 Aluminium |
| Weight Material | Brass |
Timeline
Two rounds of prototyping were produced in November 2022 and March 2023 to validate the case and PCB. The project has concluded with no plans for a larger sale.