What are some good base settings to use on a rotary engraver?

Most materials can successfully be engraved using a depth of 0.003 to 0.60 of an inch. Materials with a heavier cap layer may require multiple passes to achieve your optimal results. Begin with a shallow depth setting and increase as needed until the desired results are achieved. 

When using bits ranging in size from 0.005 to 0.125 of an inch, spindle speeds can be set between 15,000 and 20,000 RPM for best results. The general rule for proper feed rate is “the larger the bit size and the deeper the engraving, the slower your feed rate should be.”

-Bobbi Payne, Rowmark