Hi all,

After playing around with a problem I am encountering with a grinder (Macap M4d) and tried to find solutions on this forum (not successful), thought made sense to start short topic for future reference. Willing to try soluions (and post results) Anyway:

Problem analysis:
- On my minimum/finest setting of the grinder, the grinder grinds too coarse. Problem is with grinder - not coffee (fresh) nor machine
- Marker tests indicate that the burrs are aligned perfectly (under no coffee pressure obv)
- Screwing in the top-burrs into the housing, there is a a little bit of play: able to move the top part (that you screw in) a tiny bit

Solution that worked so far:
- Teflon tape! When taping 2 layers, the top part screws in more difficult and play is gone
- But it does result in perfect grind! (hence - found the problem)
- However..

Downsides:
- After 4/5 grinds the teflon tape solution is not working anymore. It shreds off/dissolves
- The grind is too coarse again
- Need to repeat the teflon method

The ask:

- did anyone experience similar problems?
- are there more structural ways of removing play between the threads? Alternatives to teflon that can/will stay longer? More static solutions?
- Or is my problem analyses not accurate?

Would hate to throw away a - else - good working machine. However, perhaps, just like cars, the machine is economically totalled..

Many thanks for ideas and help!

Are you saying without the teflon tape you can't get the grind fine enough? If you turn on the grinder and then while it's running adjust the grind finer, can you adjust it till the burrs just touch? If not, something is not right as I don't remember any stop in my M4D that would keep it from getting much finer than necessary. If you can't get the burrs to touch, figure out why as that should solve the problem. Normally when grinding the beans push the burr up and remove all the slop, so while it's not optimal, it should not cause a problem.

Wow, I never thought about thread slop as something that solves itself under force. Super helpful, thanks. Will play around with turning it finer under load and report back

Depends on which threads are off. You could try new bolts if those are off. If it's the female threads in the chamber you could cut slightly larger threads in and use slightly larger bolts.

Top and bottom burr bases are usually made of aluminum and can get damaged from cross threading or over tightening. You could go commitment fix and loctite them. If you go with the strongest loctite you might need an impact wrench to get them loose down the road. Med strength loctite would be potentially easier to remove.

There's gas line teflon tape which is more expensive but thicker than regular plumber's tape. It could hold where thin teflon doesn't.

Stock burrs should be engineered to touch at a finest setting. After market, maybe not. I 'upgraded' to 64 HU SSPs for my Ceado e37j and wouldn't you know it, couldn't get the burrs to touch. The SSPs are about .5mm less in thickness than stock. I'm putting plastic gaskets as shims underneath both top and bottom burrs to lift them up by about 1.6mm total. Still working on it. Hope it does the trick.

I don't know how the Macap grind adjustment collar works, but in the Mazzers there are springs that exert force that pushes the upper burr holder against the threaded collar (or vice versa if you want to look at it that way) which reduces the collar's "thread slop". If these springs weaken (e.g. from long use), the force they exert on the collar becomes insufficient to prevent thread slop. The solution is to replace the weak springs with stronger ones.