After his original Mantis, Felix Kuehling aka luckybipedal shared the next iteration of this unique unibody split keyboard with HEX keycaps.
The second prototype is working. It stacks a second PCB for the index finger and most thumb keys to approximate a key well and provide slight tenting – luckybipedal.
According to the author, the 8mm headers (used to stack the two PCBs) work but feel a little too high.
It actually makes my middle fingers feel short. I think I'll build another version using low-profile sockets and 5mm or 3mm M2 stand-offs before settling on a case design for the next version.
Felix Kühling explains how hexagonal keys work surprisingly well in an ergonomic layout without fine-tuning parameters like hand rotation, column stagger and splay.