So I recently did a full cleaning of my Quamar M80e bought new in January 2015. This is the third time cleaning it, and I wanted to catalog some of the process. I also wanted to show exactly how much coffee is retained by the grinder.

I was always throwing my first shot, they were quick, first drops were black and it blonded quickly. Successive shots were always much better than the initial, so I got used to throwing away the first shot. I started purging a little, then a double shot worth of grounds (16g) and saw a marked improvement. Drinkable, pulls well, but still not the best. On a busy morning it will do, but on a weekend, it must be perfect. The last times I cleaned the grinder, I did see a lot of retention, which I always suspected was the issue.

The dismantling process is pretty straightforward, following the many resources available on YouTube.
- Remove the hopper
- Remove the top burr retainer screw- this just prevents the top burrset from fully unwinding if you don't hold it in place.
- press and hold the plastic adjustment pin and Unscrew the top burrset to separate

That's all there is to it, you are now ready to clean. Here is how mine looked after <10lbs of light to medium SO Ethiopian:


I did clean off the top burrset on the top so I can capture as much of the grinds as possible. Notice the ring on the outer edge. That is solid coffee packed into the space between the burr carriers. Notice the top burr carrier cleans up pretty quickly and easily.


With the flash to highlight the dark recesses

After cleaning thoroughly to dislodge the coffee, I used a pick and got into the crevasses. The sweepers also hold a small amount and needed to be picked on top and the leading edges. The other major retention area is the chute:


After fully cleaning, picking and dislodging as much as I could, here is the result:


Subtract 20g for the weight of the container. After my last beans finished, I was able to tap the machine and had 10.8g fall out. So the total retention is around 23g. Granted, some of the grounds will not move out like those packed between the burr carriers, or around the leading edge of the sweeps, but the moveable ones like in the chute will:


Now clean up and put it all back together:


Overall, I still like the grinder for the features at the price point, simplicity of maintenance, ease of use, just beware of the grind retention and you will be rewarded with great coffee, which is what we're all after.

That being said, I have upgraded to a Mahlkonig K30 and the difference is completely noticeable from an everyday use point of view. A few months in, I will try a cleanup and measure of grounds in that machine to compare with this one.

Thanks
Roger

Thanks for posting such a wonderfully detailed description of what lurks inside; it'll help all of us M80 owners know more about our grinders.

Hehe...looks like a gaggia mdf assigned espresso duty

Nicely done. Fact is, ALL grinders tend to "retain" stale grind in the areas you picture. It generally doesn't impact taste, as excess will just spill of the "hardened" coffee rings.

I describe "retention" (YMMV) as being what the grinder retains in the area just prior to the chute and the chute/nozzle itself. That's why MOST large conicals retain more. Their pathway from burr through the chute is significantly longer, than say a Mazzer Major or better still, a K30 Vario. I believe counting the stuff just prior to the fairly short chute area, the K30 retains about 7 grams, depending on how oily the bean is. I own one, along with the Baratza Forte, which retains on average (in espresso use) about 2 grams, if that. Theirs is a unique design, and why the BG version and the Vario are popular in cafes. With coffee prices rising a bit, less waste is always a good thing.