You can chisel out mortise and tenon joints in timbers by hand, program a CNC milling machine for the task, or you can use LignaTool’s router system. Their system lets you create dovetail mortise and tenons for connecting timber without fasteners.
The system is comprised of a mortise template and a tenon template. Both have sliding fences built in for quick setup. With the LignaTools templates you can make mortises and tenons in wood cross sections from 3″ by 3″ to 8″ by 15″ — plus you can vary the tenon length and make joints with compound angles up to 45° in both directions.
Here’s the bad news: the templates alone will cost you $4000. An 8° or 15° router milling bit will run you another $400, and there’s also the matter of having a 2000W heavy-duty router that can handle milling timbers.
LignaTool [Timber Frame Tools]