Years ago, I found the users on this forum to be a valuable asset for testing all manner of theories on how to make coffee better. And sometimes prove what didn't. I thought this a good place to start for some serious feedback on something I've come up with to align coffee burrs, sharpen cutting edges and reduce friction. I've gone up through all the grinders I have in my shop and am looking to put some of these things out in the field to see if it makes a substantive difference.

We've all been down the rabbit hole of using magic markers to see if burrs line up and it doesn't take much for them to be off. Instead, I am using adhesive honing disks fitted to the surface of one burr to flatten and highly polish the other in the grinder. Once done, the result is two perfectly mated burrs with a near mirror finish and a ridiculously sharp edge.

I have 3D printed alignment tools and pattern cut disks for Mazzer 64's, Majors, Mythos, Ceado 64, Rossi-because they fit a lot of machines, and K30's.

I am happy to talk about the process and field questions, but could really use a few fellow coffee nerds to check out the process.

If needed, I can volunteer a Rossi (Nuova Simonelli MDX). I have a set of now-ridiculously dull original burrs from years of commercial use, as well as a new set of Italmills that have only been broken in (with rice). It is my back-back-backup grinder .

Looks good; but I have a dumb gotcha question -- can the metal shavings cause a problem? Do you clean everything out with Grindz or rice afer the polishing is done?

Funny thing about that. The metal hanging on to the edge of mills from the factory under a scope is pretty scary. Because we are honing the surface of the teeth perpendicular to each tooth, it removes all the crud. While a good idea to run some coffee through the system after doing anything, adjusting the grinder is sufficient to clean. If anything, the breakin period for new mills may be unnecessary.

Here are a few close up photos, these are factory fresh food friendly mills:





And these are after two passes:

What happens with burrs that are coated? Does the honing process significantly reduce life of the coating?

I'd like to volunteer a Mazzer 64 (Mini Electronic). New OEM burrs are ~18 months old, so 20kg or so.

If it's all 3D printed and postage is cost-prohibitive(or plain slow) let me know if there is a way to print it on a mates printer as a one off that protects your IP- could prob do it as a remote desktop or something.

I haven't tried them on coated mills yet, though I have a set in a grinder prototype. The coated mills may require a different honing disk.

Since we are only surfacing the flat part of the mill to lap the two surface to each other and revealing the edge, I don't think that lifespan would be impacted. The vertical reveal of the tooth isn't touched and the flat portion doesn't actually do any cutting. There is some benefit to removing the surface imperfections of the original mills. The rough surface creates friction against the coffee particle and may produce even more fines. Eliminating that component, we hope, could result in more consistent partial size.

We would have to test it first. We are curious to see if these can be used to restore the cutting edge to larger, more expensive burrs like the ones in sitting or Mahlkoenig grinders. It wouldn't work for crushing type mills, though.

Maybe. The tool insures the honing disk is centered on the mill so centripetal force doesn't spin it off. It has the side benefit of centering the screws on grinders that have a little lateral play. Would still have to send the disks, though, and the 3D printed tool is carbon fiber, very light.

I hope in the wild testing shows promise. I like the way you're thinking.

Me too. I know it will align the burrs, but I really want it to make a real difference in extraction and flavor profile. Maybe too consistent a partial size is a bad thing.

I have more of an explanation and photos on the projects section of my site:

https://analogue.coffee/Projects/

Here is a video with sound comparing factory mills and honed mills.

https://www.icloud.com/sharedalbum/#B0W5yeZFheJSyr