I got my hands on a secondhand Mazzer Super Jolly (rebadged by Astoria) – the owner said that a broken timer switch prevented it from turning on properly, but that it worked fine otherwise. I didn’t think it was appropriate to try wiring out the grinder to bypass the switch before buying it, so I took quite a jump of faith and sprung for it.

The good thing about buying coffee grinders is that they are remarkably simple in build (save for the fancy grind-by-weight ones). At its core, they consist of a strong motor connected with some sort of power switch. I was very surprised to find out that the seller was indeed right: it was just the switch!

The switch closes the grinder circuit when the wheel pushes the two "hockey stick" contacts out to engage with the smaller strips of copper. If you look closely, the hockey sticks are broken right at the elbow, probably from heavy use. It's interesting that they both broke!

When buying a used grinder, the most important part to check for functionality is the motor. If the motor is burnt out, then it’s usually very hard to replace it, as the motors are usually made in custom form factors in batches for the grinder manufacturers. For Mazzer grinders, the motor is hammered into a cast aluminum case, which makes it impossible to pull out and push in a new one with regular garage tools. After taking the switch out of the circuit, the motor ran like a charm.

I gave the grinder an initial clean and things started looking a little better.

It is indeed a Mazzer!

I also boiled the metal parts in citric acid, which may have been a mistake, as many of the steel parts started oxidizing…

Most of the doser assembly and upper burr carrier could be removed and disassembled by screws and bolts. The lower burr carrier is pressed into the motor shaft, and the entire motor assembly is pressed into the cast aluminum frame, so I decided to keep those in their place. That meant there was a fair bit of grime that I couldn’t wipe, but some patience with a toothpick, drinking straw, and vacuum got rid of a lot of the grind buildup.

Chute view. The lower carrier is the bright silver piece that you see through the middle of the chute. The grinds I had to poke and chisel out are the dark spots underneath.

Most of the doser came apart relatively easily. There was a little pocket immediately outside the spinning doser shaft where grinds slowly fall in over the years. Those grinds have gradually rolled themselves into little balls of ground coffee. I almost thought they were huge ball bearings until one broke apart when I poked it. Pretty neat and gross at the same time.

The actual doser container will take some work though. There’s about a millimeter of hardened grime on the clear window that will call for some elbow grease.