Well... no, this is not a coffee grinder but an overkill casing for a little pencil sharpener.
Inspiration came from those vintage coffee grinders and thus the name.
The OpenSCAD code (what a shame!) is included into the ZIP file in the same folder than the single STL files. There's some changes in the code to allow you to see the OpenSCAD views.
The "to do" list for this thing is huge but I let it just like this, improvements should come as a derivatives.
I post it as a derivative of Public Domain Involute Parameterized Gears by LeemonBaird because I have reproduced (copy and paste and may be... some little change from) most of the code of that thing.
It also requires parametric_involute_gear_v5.0.scad by GregFrost which I picked up from http://www.thingiverse.com/thing:3575
And my own Poor man's openscad screw library available at http://www.thingiverse.com/thing:8796
Everything* is snap-together with very narrow tolerances in most of the cases.
(* but the last part which is a sort of nut)
Cleaning the excess of material from the 1st layer is required or the parts will break or not move smooth enough. Once assembled they are strong enough to do their job without issues.
UPDATE: I printed a second unit to double check what I uploaded, all PLA, and the only cleaning was to remove the "sticky pads" in the gears holder and crank bearing. (end of update)
"testing_plates.stl" is not required, those plates are embeded in the box case. I have included this STL to allow testing the "bearings" without having to print the box (and save material and time in case of things not fitting properly).
I used ABS for the moving parts and PLA for the case and the crank (as mentioned in the update above, my second print is all in PLA and it works as fine or better than the 1st one)
"bearing.stl" is not required anymore, the "gears and stuff" STL has been replaced with a version that has all the parts and also, some ugly "dangling edges" have been erradicated.
The two OpenSCAD views that should show how things go together before closing the box have been added to the code (more details in the description)
Before you start:
Consider printing a few litte parts, i.e. a spacer and a bearing, and see how they fit (or not) together. You'll be very disapointed if there's no way to make them fit after printing a whole bunch of parts!
Following the OpenSCAD views assemble first gears, spacers and bearings. For example, the right side of the exploded view: place the bevel gear upside down in a flat surface, align the tabs of the spacer and carefully press down, then add the bearing in the same way.
When the 3 sets of gears are ready, add them to the support/holder/whatever.
If your pencil sharpener fits inside its housing (you're lucky!!) jump to the next step. If not, drop me a line and we'll see what can we do!
Assemble the fat disk of the drum with the gear and the bearing like in step 1.
Enclose the pencil sharpener with the flat plates, add the thinner disk and insert the other end into the cavity in the fat disk.
Let aside everything from the previous steps and begin to put together the box. Start with the back plate (the one without the holes for the pencil and the drawer) one side and the bottom. From the two pegs in the back pannel, the fat one is the bottom, thus the thinner one goes on top.
Add all the geared stuff to the back plate and snap together the front pannel starting by the bottom and letting the top a little bit open.
Make sure that the gear lock and crank pegs are in place and add the top and the remaining side pannel.
Add the crank handle, secure it with the hemispheric nut and place the little drawer.
Figure out a way to use this thing with only two hands! I used double sided tape :)