COBRA CRUSHER

Get a better grind by keeping the chains loose. If you are getting little pebbles in your grind. Loosen your chain until the bolt is just outside the locking nut. The chains will spin around more freely and catch the pebbles that might get stuck out of the path of the chains. In the picture above, the grind on the left side was with tighter chains the grind on the right is from really loose chains.

Don't overfill your crusher or use a low powered grinder. You could smoke your grinder if the chains can't get RPM.

Put a small handful of rock in the crusher and start the grinder. In 15 to 20 seconds you will have a finely ground sample of your ore.