Final answer:
The dimension tolerance for a rabbet milled with a portable router can vary, with newer research suggesting larger tolerances. Guidelines suggest tolerances up to 8 diameters side-to-side and 15 diameters deep.
Step-by-step explanation:
The dimension tolerance for a rabbet milled with a portable router depends on various factors. Historically, a common rule of thumb was to have a tolerance of 5 side-to-side and 7-8 deep. However, newer research suggests that a tolerance of up to 8 diameters side-to-side and 15 diameters deep can be achieved.
For example, if the diameter of the rabbet is 1 inch, the tolerance for side-to-side dimensions would be up to 8 inches, and for the depth, it would be up to 15 inches.
It is important to note that these guidelines may vary depending on the specific requirements of the project and the type of material being used.