Determining the optimal settings for your laser engraver on slate involves several steps. First, consider the wattage of your laser engraver. Higher wattage allows for faster engraving but may lead to excessive burning or chipping if set too high. Start with a low power setting (around 20-30%) and adjust as needed.

Next, test different speeds. A slower speed allows for deeper engraving but increases the risk of damage. Experiment with speeds between 100-300 mm/s, noting how each affects the finish.

Additionally, select the appropriate focus height. Improper focusing can lead to blurry engravings. Typically, focus your laser a few millimeters above the slate surface for best results.

Finally, consider the use of air assist to reduce smoke and debris during engraving, which helps in achieving cleaner results. Also, run multiple test engravings on scrap pieces to dial in your settings.

Keep detailed notes on your results to identify the ideal combination of power, speed, and focus for your specific slate material.