Opus has two grind adjustment rings: an outer ring and an inner ring. Use these rings to set your optimal grind size. To see what settings we recommend for common brew methods, see the grind guide inside of Opus’s load bin lid. You can also find the grind guide in the Get To Know You Guide and your Opus Gear Guide.We created a handy video to explain the inner adjustment ring here. The outer ring The outer ring can be seen when looking directly at Opus. This ring can adjust between numbered settings from 1 to 11. On this outer ring, 1 is the finest setting and 11 is the coarsest. Between each numbered setting are 4 minor increments, allowing you to set your grind setting by increments of 0.25. The inner ring Inside Opus, there is a second inner adjustment ring. You can access the inner ring by removing the load bin. Use the inner ring to: Enable micro adjustments on the outer ring. By adjusting the inner ring by one notch, you shift the range of the outer ring by 2/3 (.667) of a notch. Because the outer ring is measured by increments of 1/4 (0.25), utilizing the inner ring enables Opus to get between those increments by 1/6 of a measure. If you really want to geek out: One outer ring adjustment is equivalent to 50 microns of burr height movement. With the inner ring design, you can split those outer adjustments into 3rds, allowing for 16.7 microns of burr adjustment throughout the range. To expand the grind range on Opus. By adjusting the inner ring all the way to the one end or the other, you enable the outer ring to reach setting “0” (1 full setting finer than 1) and “12” (1 full setting coarser than 11). This is because there are a maximum of 6 notches on the inner ring, and 6 inner notches is equivalent to 1 full outer setting. To calibrate Opus as the burrs wear down. With prolonged use, the burrs may start to output coarser grinds. To adjust for this, you can slowly shift the inner ring to a finer setting. Though the burrs are built to last for the lifetime of the product, burr wear is natural.How to adjust the inner ring:1. Ensure the load bin is empty. 2. Rotate the outer ring until it is centered at setting 6. 3. Remove the load bin by twisting it counterclockwise until it unlocks from the grinder, then lift away. The blue inner ring should now be visible. 4. With your thumb and index finger, press down with even pressure on the two exposed tabs of the calibration ring to compress the spring-loaded mechanism. Keep pressing until you feel the ring bottom out. 5. With the inner blue ring pressed down, use your other hand to rotate the outer ring in either direction, which will change where the arrow is pointing on the inner ring scale (counterclockwise towards the “-” is finer, clockwise towards the “+” is coarser). 6. Each notch on the inner ring is equivalent to 2/3 of a minor increment on the outer ring. Each minor increment is 0.25, so each inner ring notch is equivalent to ⅔ * ¼ = ⅙ of a numbered setting. There are a total of 6 notches on the inner ring in either direction. 7. When you’ve reached the desired setting, release the calibration ring so it springs back up and engages with the grind adjustment ring. Rotate the grind adjustment ring to ensure the calibration ring rotates with it again. 8. Finally, reinstall the load bin. Please make sure the load bin is fully seated and the Opus turns on. If the Opus does not turn on, you may need to readjust the load bin. This is a safety feature to ensure everything is locked into place.