The miter guide can be printed in PLA/ABS/PETG. It will need two countersunk M6x12mm screws, two washers and two wingnuts. The guide is made for a small japanese saw. For wider blades, there is a second guide that can accept a sacrificial piece, made from 4 mm plywood or any other scrap material. Mounting the sacrificial piece will need another two M6x12 screws and two M6 hex nuts. The distance between the holes for the sacrificial piece is 60 mm. I used a brim for printing the base upwards for better adhesion and to avoid using supports. I recommend printing at 0,2 resolution for accuracy, but at 0,28 it is still acceptable. I also used 6 walls and 6 layers for top and bottom, with 20 percent infill, so in the clamping area it is near solid.
The markings are for 0, +/-15, +/-22,5, +/-30 and +/-45 degrees.

Update Feb. 01: went to the hardware store to find that M6x12mm countersunk screws are some oddities that they never have. So i made some modifications and come up with a version for M5 countersunk screws (i do not mess with the height any more because i don't know what i will find, but it need to be at least 12mm). For the sacrificial piece, i have left the same M6 screws.

Creality

Ender 3

No

No

0.2

20