Slow feeder for coffee grinders

For coffee lovers, grinding is as important as the rest of the process. For this, we have the slow coffee bean doser for the grinder

The printing is very simple, everything is prepared so that not a large amount of supports is needed, the part fitting is calculated so that any printer can do it without problems

I bring you several printing profiles, with AMS for the white part of the button. Without AMS for those who do not have this option, so the button has the power symbol marked, and the most comfortable version to print, with AMS and using PETG as support filament, with 0 distance between parts, which provides a perfect finish on the parts that use support. In any case, it is not necessary to use this version as it is only a visual finish and does not affect the final operation at all, it is only aesthetic

For the motor, in my case I have used the double-shaft MakerWorld model, it was the only one I had available, which is still a bit tall and needs a potentiometer to adjust the rotation speed, so I had to cut the excess shaft. The option is to use the MakerWorld motor “N20 Single Shaft Worm Gear Motor (1PCS) - LA008”

ATTENTION - BEFORE ORDERING A MOTOR FROM ALIEXPRESS, CHECK THE MEASUREMENTS, SOME ARE VERY LARGE AND WILL NOT FIT INTO THE PRINTED MODEL

Thanks to Kamlotton's feedback, the correct model is the N20 from AliExpress

The wiring, if we start from the MakerWorld motor, forces us to make modifications, cut wires, battery terminals, and add a potentiometer to adjust the speed

Inside the motor compartment there is enough space to use all MakerWorld components, house cables, control boards, and potentiometers

Regarding the wiring, it is very simple

Once all the parts are printed, we begin assembly, it has no more complication than following the steps correctly

We start with the piece that houses the motor and batteries. We install the battery plates and the motor, routing all cables so they don't get caught under the motor

motor cable position so everything fits without problems

The other battery contact plates placed in their position

and the button which we do not yet place in its final position. The outer cover must be installed first

The final assembly without using a potentiometer is like this

If we use a potentiometer, we attach it in the designated part with plenty of space. The MakerWorld potentiometer does not fit in the available space, you will have to get a compatible one, although the ideal is to use a low RPM motor

We place the motor holder so it doesn't move and install two M2 screws. We will use the same screws to fix the power button, two M2

We assemble the outer cover of the motor. Those holes are for alignment if necessary. Nothing needs to be done with them if the model prints correctly. Otherwise, an M1.5 screw will be used to fix and align them

We put the cover on the motor and battery compartment. We secure it with an M2 screw

We place the magnets respecting the same polarity on the entire face. The holes for the magnets provide a correct fit on my printer, designed at 3.2mm with material expansion and glue they fit snugly, but I recommend using a 3mm drill bit, rotating it manually to clean the outside of the hole. Other ways are to use a press. Do not use heat to soften and insert the magnet

We install the magnets in the rest of the parts, respecting the polarity on each face and the inverse on the connection piece. The magnets I have used are 3x2 N52, they provide a strong hold

For the dosing elements, it is not necessary to use 8 magnets, just one is enough, moreover, with just one it will act as a clutch element if a coffee bean gets stuck. Using more magnets will stop the motor. I leave it to your preference

I have preferred to print the dosing parts with support and no spacing in PETG, so the finish is much nicer, but in any case, they can be used without support in PETG

The support peels off without leaving a trace

Without supports in PETG, the finish is worse, but it doesn't lose functionality

We place the dosing clutch with its magnets installed, and now we can use our coffee bean doser

The finished product

The complete kit

This is how it works

I hope you like it and enjoy it, thanks for getting this far