Monolith MC4: unusual sound/knock

#1: Post by **DaumierS** » June 4th, 2022, 6:55 pm

After grinding about 11 lb of coffee beans using my new Monolith Conical MC4 (received a month ago), I noticed a strange "knock" that you can hear in the following video:

It is actually a bit louder than in the video, and it sounds metallic. Is it normal? The knock does not go away if I change the grind coarseness.

The grind itself seems to be OK. Is it normal? What do you think?

Thank you.

#2: Post by **PIXIllate** » June 4th, 2022, 8:36 pm

Have you checked that L shaped bean sweeper arm isn't contacting anything by spinning it by hand? That part can be bent and reshaped as needed. Have you contacted Denis?

June 4th, 2022, 8:48 pm

Yes, I checked it. It looks OK, no contact.

I recently had a problem with my new MAX as well, and I do not want to bother Denis too much. I will write to him if I am sure this knock is not normal.

#4: Post by **PIXIllate** » June 4th, 2022, 9:27 pm

I don't have that noise on my MC4 from a few months ago.

#5: Post by **bakafish** » June 4th, 2022, 10:33 pm

It looks like the same problem.

http://www.youtube.com/watch?v=0Fd5uubn5Rg
https://twitter.com/motoking/status/1474342015421001731

https://twitter.com/motoking/status/1474601800808677383

by Google translation:
I think that the malfunction of the monolithonical is probably the abnormal noise caused by the misalignment of the shaft when this mounting bolt is loosened, but even the monoliths that are checked and shipped one by one will cause this kind of thing Although it is not necessary because it will loosen even with vibration and shock during transportation.

#6: Post by **PIXIllate** » June 4th, 2022, 10:58 pm

Rather than speculate contact Denis.

#7: Post by **bakafish** » June 4th, 2022, 11:26 pm

PIXIllate wrote:Rather than speculate contact Denis.

I asked Denis before. He said it is normal even I had attached the YouTube video clip in the #5 directly in the email. He said:

Ken, that is a normal sound for a grinder. This is a mechanical device with a lot of moving parts. It will produce different sounds that come and go. There is nothing wrong with it. Use it.

I asked him to see that video clip and he replied:

Ken, I am sorry but it is normal. Likely the noise is from the drive key which is loose.

#8: Post by **CASmessage** » June 4th, 2022, 11:47 pm

Today was a pre-order day for the MC4. As such I think I speak for a bunch of us when I say we'd love to know what Denis thinks.

June 5th, 2022, 12:02 am

I asked Denis. Let us see what he thinks. The grind quality seems to be OK despite the noise. I will measure the TDS in the coming days, and will use the Kruve sifters to see what the particle distribution is, and report...

#10: Post by **rmongiovi** » June 5th, 2022, 12:25 am

bakafish wrote:I asked Denis before. He said it is normal even I had attached the YouTube video clip in the #5 directly in the email. He said:

I asked him to see that video clip and he replied:

My question back would be, "If something wears out prematurely because this noise is indicative of excessive wear, will you cover it?"

Then decide what to do based on his response.