If you need a cheap DIY jig for mortise and tenon making for your woodworking projects here is a simple 3d printable version that uses a Dremel tool for cutting out the wood.
It was developed by Crafted3D since he needed a cheaper alternative for a 1000USD standard router.
There are a few non-printable parts like a metal clamp, but this is a great low-cost shop tool. You could also design different templates for the shape of your tenon/mortise parts.
Instructables page with all the files: