2025-02-27 - Cleaning a Severin KM 3872 Coffee Grinder
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I have a Severin KM 3872 coffee grinder that I bought used for 2€
quite a few years ago[0]. If the cutting blades look a bit battered,
that's because I tried to grind something that ended up being a bit
too much for this device. The annoying thing with these simple coffee
grinders is that they aren't very easy to clean properly. You can
sort of clean them with a damp cloth, but there will still be dirt
stuck in the middle underneath the cutting blades. If you only use
them for grinding coffee beans, that doesn't matter, but I use mine
for making powdered sugar and grinding all sorts of spices, so I do
want to give it a deep clean once in a while (I've never actually used
it for grinding coffee beans). It isn't actually too difficult to do
that, but you do need to know a little trick to get the cutting blades
off, so I thought I'd write a small guide on that.

WARNING: This is a mains powered device. Don't open such devices if
you don't know what you're doing because they can kill you.

One problem is that a special triangular screw is used to attach the
bottom part of the housing[1]. I happen to have a matching screwdriver,
but I'm not sure if there's any hack to open these types of screws
without a matching screwdriver. After removing the screw, the bottom
is only held on by two clips, but two plastic rings first have to be
removed in order to be able to press those clips together[2]. The
bottom part can then be removed[3]. It can't be removed completely
because the cable goes through a small hole in the side, and the
plug doesn't fit through that, but the cable is long enough that
the bottom part can be put aside while working on the rest of the
device. Note that there's a small plastic part at the bottom that
easily falls out[4]. This is part of the mechanism for pulling the
cable into the device by turning the bottom part. Just make sure it
goes back in the right place when putting the device back together.

The top part of the housing can just be unclipped at the sides[5],
after which the cutting blades can be removed. This is the part where
you need to know a small trick. The bottom of the motor shaft has a
slit in it that can be held with a flathead screwdriver while turning
the cutting blades by hand in order to unscrew them[6]. The bottom of
the shaft isn't directly accessible from the bottom, but it's possible
to move the entire motor assembly to the side a bit, as shown in [6].

The metal container for the coffee/spices/sugar/... can then be removed
completely in order to clean it properly[7][8]. During reassembly,
the plastic ring has to be placed on the motor shaft on top of the
felt ring[9] before the metal container can be placed on top[10]. The
cutting blades can then be screwed on while holding the motor shaft
with a screwdriver again.

Afterwards, the top part of the housing can be clipped on again,
after which the bottom part can be screwed on. Don't forget to put
the plastic piece for the cable winding mechanism back in the correct
place, and add the two plastic rings before putting the screw back in!


[0] gopher://lumidify.org/I/phlog/2025-02-27-severin-coffee-grinder/coffee_grinder.jpg
[1] gopher://lumidify.org/I/phlog/2025-02-27-severin-coffee-grinder/bottom.jpg
[2] gopher://lumidify.org/I/phlog/2025-02-27-severin-coffee-grinder/bottom_unscrewed.jpg
[3] gopher://lumidify.org/I/phlog/2025-02-27-severin-coffee-grinder/bottom_removed.jpg
[4] gopher://lumidify.org/I/phlog/2025-02-27-severin-coffee-grinder/bottom_cable.jpg
[5] gopher://lumidify.org/I/phlog/2025-02-27-severin-coffee-grinder/top_plastic_removed.jpg
[6] gopher://lumidify.org/I/phlog/2025-02-27-severin-coffee-grinder/motor_shaft.jpg
[7] gopher://lumidify.org/I/phlog/2025-02-27-severin-coffee-grinder/top_removed.jpg
[8] gopher://lumidify.org/I/phlog/2025-02-27-severin-coffee-grinder/top_disassembled.jpg
[9] gopher://lumidify.org/I/phlog/2025-02-27-severin-coffee-grinder/top_reassembly1.jpg
[10] gopher://lumidify.org/I/phlog/2025-02-27-severin-coffee-grinder/top_reassembly2.jpg