Rancilio Rocky - coffee collecting under burrs - why?

[MrtnS]

Hello!

Hoping someone might be able to share some wisdom on this topic.

Been using Rancilio Rocky since about 2017, fairly regularly (daily). Chemex, French Press, and Moka Pot methods.
For the most part it has been very reliable. I had done some basic cleaning an maintenance over the years but nothing too crazy.

Recently I had some grind inconsistency and tried to recalibrate.
First cup seemed good, but then it became inconsistent again. I figured something was off, and the next time I had examined the burrs there was a pile(!) of coffee and grindz under the bottom one, as well as coffee collecting in between the top burr and it's attachment. I thought that was strange, so I cleaned it up and made sure that the burrs were tight as I could get them when I recalibrated.

I've included pictures. This is after cleaning out comepletely and only grinding about 25g of coffee!

obviously it should look more like this


It makes sense to me as to why this is messing up the grinding and inconsistency, and making sour coffee. But how do I prevent it?
Does it seem like a "buy new burrs and screws" kind of fix?
Has anyone else run into this problem?

Thank you

[bgnome]

I have different flat burr grinders and they both accumulate grinds under the burrs. It is possible that some exchange occurs here between old and new grinds. If it really bothers you, you can fill the void with some sort of spacer, as long as it does not interfere with the mounting.

[Pressino]

As noted, many flat burr grinders, like the Mazzers, collect a small amount of grinds under the burrs. I notice that your grinds are pretty coarse (I guess for your French press). If you are noticing a distinct fall off in the taste of your brewed coffee, I would guess it's due to something other than the accumulation of grinds in that location (which usually remains in place there or gets quickly cycled through). When you say you "recalibrated" the burrs, what exactly did you do with them?

[Randy G.]

If it has seen regular use for five years it would likely benefit from new burrs. In seven years of mostly espresso use mine was ready for its third replacement set when I sold it. In any case, they are not expensive so worst case you keep the current set as a spare.