This is a coffee bean grinder. It's essentially hand powered burr grinder with 1mm radius sized holes for coffee grounds to come out of. It's a very simple job requires 3 prints, 2 3mm nuts and bolts and a glue gun for sealing. Use it by putting beans in the top and turning the burr a lot, this process is tedious and needs some arm power. ** The photos are the original version of the grinder with less refinements but it's the same idea. Here's a video of it in action ! https://www.youtube.com/watch?v=LS-nceswKVQ&feature=youtu.be Ok so after all the parts are printed you may need to drill out the grind holes depending on how your printer performs. Insert the Centre Burr into to the cylinder. The outer burrs of the cylinder should be on the bottom of the device and it'll keep the inner burr that you spin inside the device. Next screw in and glue the base (the screws will help the glue from seperating) If you really don't want to use any non 3d printed parts other than glue, apply glue then heat gun it to give it extra stick, thats what I did. Job done!