Making a Cimbali Junior Grinder Doserless

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#1: Post by Spencer »

To the extent there are still Cimbali Junior or Max grinders floating around, and anyone finds this useful: My Junior was for home use and I grew to really dislike the doser and the coffee waste. As everyone has noted, there is no easy way to make it doserless. I changed to a Fiorenzato F4 and the Junior has been sitting around. Since it didn't seem to have much of a resale value, and since I had some wood leftover from another project, I decided to scrap the case and see if I could make something more useful. The axis of the grinder is tilted 15 degrees to help the flow of coffee out of the chute. The square bit of wood at the top of the chute covers a half inch hole for cleanout and is held in place by small magnets and a washer glued to the chute. I used a 3D CAD program to create a sleeve to direct the beans to the burrs and then had it printed at Jaws Tech in Idaho. At the bottom of the sleeve there are cutouts to fit over the three brass pads that hold the screws for the lower burr. The inside diameter is small at the bottom 25 mm of the sleeve and matches the opening of the top burr. The sleeve sits on top of the burr and not the brass carrier. From the wider inside diameter at the top to the narrow inside diameter at the bottom there is a 60 degree bevel so ground coffee won't accumulate on a ledge. Anyone wanting the STL file to have a print made is welcome to it. A close facsimile can be made with 1 ½ inch PVC pipe and a Dremel tool as someone else shows in another H-B post. So far it's working nicely as a single dose grinder. The only part left to make is a black plastic sleeve for the shaft of the grind adjustment knob.


#2: Post by bgnome »

The wood is an interesting choice. I would like to see the parts you modeled as well as how you went about designing the chute. I'm still not super happy with what I have on my Cimbali Max at the moment..

Spencer (original poster)

#3: Post by Spencer (original poster) »

Hi Bruce

The wood was less a choice than the fact I had a board left from another project that was just big enough to work. The grain pattern makes the glue up less visible. Inside there is some white ash for the grinder base and to hold the screw inserts. The sides and back are glued together as one piece. The front and top are each separate pieces. Just as in the original, the power switch and light have to be disconnected to take the grinder out or take off the front panel completely. The wooden wedges at the back of the base tilt the grinder 15 degrees forward.

When I took the grinder out of the case, I used a Dremel tool to cut some of the aluminum chute on the grinder. It has a bit of a flange on the front which is what I took off, as well as flattening the outside edges a bit. The wood for the chute is around 2 - 2.5 mm thick. It was re-sawn from a thicker piece, and I was less worried about an exact measurement than a uniform thickness. There is a short "U" shaped piece that fits over the top of the aluminum grinder chute and the two sides. That comes out to the edge of the frame you see in the picture. The bottom piece of the long square (angled) chute extends up to below the mouth of the aluminum grinder chute and is glued to the "U" shaped piece as are the sides of the long angled chute. The inside of the wooden chute and the aluminum opening of the grinder are coated with confectionary glaze which is edible shellac used in candy and pastry and available on Amazon. I used vodka as a solvent. I wanted to try and keep the pathway for the ground coffee as smooth as possible.

I've added a rendering of the sleeve going down to the burrs. It was printed using SLS printing and is made from Nylon 12, which I understand has FDA approval for food contact. The post processing was just tumbling to smooth out the surface. If you want a drawing with dimensions or the STL file (or another format) just send me a private message and I'm happy to send it along. Similarly if you have any other questions.