Good idea to remove the lower burr carrier?

#1: Post by **Yamin** » August 11th, 2020, 2:50 pm

Hi guys,
Just sparked a question about the low burr carrier of grinders - I noticed that with 'cleaning and maintenance' videos and literature doesn't call for removing the low burr carrier at all. (grinders with flat burrs mainly). I could imagine that coffee oil and ground would be caked on the bottom of it as well. Could there be any reason as to why this is?
Also I know that its a bit tough to remove the low burr carrier- well with the grinders I have to work with anyway. Eg. Mahlkönig K30, Mazzer Super Jolly. So any tips on doing so would be greatly appreciated.
Thanks in advance.

#2: Post by **Randy G.** » August 11th, 2020, 3:06 pm

There is little reason to remove the lower burr, and unless there is some specific repair that requires it I would recommend never trying to remove it. Nothing to really gain, and the reward could be major misalignment. Many of the larger, commercial grinders (like the Mazzer) base can be easily removed, so cleaning that area is easily done with a screwdriver and an air compressor. Even the grind chamber can be sufficiently cleaned with the top burr carrier removed with just a brush and compressed air blasts.

And still, after you clean it out, the first two or three uses and you are pretty close to being back where you started.

the tldr; don't worry about it.

#3: Post by **TallDan** » August 11th, 2020, 4:42 pm

I'd say that it depends. I got two mazzer minis and a super jolly a while back. They were all from a cafe of some sort and had clearly been heavily used, but not recently cleaned. The first mini I cleaned and didn't remove the lower burr carrier because the grind chamber wasn't terrible. The second mini was noticeably dirtier and I was glad that I did pull it and get it cleaned. I currently have the super jolly taken apart and have been struggling to remove the lower burr carrier. I haven't decided yet if i'm going to give in and let it be or not.

If the grinder has been used in a home setting, it'll probably never be used heavily enough to matter too much. In a commercial setting, especially if used for a lot of dark roasted coffee, things can get pretty gross in there.

The mini's lower burr carrier I was able to remove easily enough with some pressure with a screw driver slid in through the exit chute of the grinder with the doser removed. For the SJ that didn't work for me. The trick that I found in another thread here on h-b is to get some long bolts that match the thread of the burr mounting screws (I believe it's m4 thread). They will thread right through the holes and then if you slowly tighten them, they'll pull the burr carrier out by pushing against the bottom of the grind chamber.

Digging through my jar or random hardware bits in the garage, I only found two bolts that fit, and then bent one trying to get it out. That frustrated me enough that I put it aside for a few days.

#4: Post by **nahau** » August 11th, 2020, 7:29 pm

Although not a good idea to pry up the carrier though the exit chute, sometimes it readily works. If you're having issues removing the carrier, use a heat gun to heat up the carrier around the motor shaft, then use screws like in the linked post. The carrier should pull (or push) right up.

Macap M4 Lower Burr Carrier Removal

August 12th, 2020, 4:03 am

Thanks for the response guys, the grinders I have to clean are mainly used at cafe' settings so they are heavily used. The reason why I thought about this was actually - I was working on a Mazzer grinder (I forgot which model) which had conical burrs and the bottom burr holder came out nicely and the underside was filthy.

Randy G. wrote:Nothing to really gain, and the reward could be major misalignment.

This is what I'm really afraid of. Could you please let me know what sort of misalignment I might get. The motor shaft going to one side or the bottom burr not sitting parallel?

I have read about the long bolts method, and I thought wouldn't that scar the bottom of the ground chamber?
I have also seen a grinder which someone had previously tried to pry the bottom holder with a screw driver through the chute, it looks very damaged.

#6: Post by **JRising** » August 12th, 2020, 7:44 am

Yamin wrote: This is what I'm really afraid of. Could you please let me know what sort of misalignment I might get. The motor shaft going to one side or the bottom burr not sitting parallel?

I have read about the long bolts method, and I thought wouldn't that scar the bottom of the ground chamber?
I have also seen a grinder which someone had previously tried to pry the bottom holder with a screw driver through the chute, it looks very damaged.

The misalignment of the entire lower burr carrier not seating perfectly when reinstalled.

And, Yes. The screws will leave marks on the bottom of the grind chamber, a screw driver pounded up through the chute will leave marks on the lower burr carrier. If you have to do it, then study the specific grinder you're working on and do it with as little damage as possible. Even a proper gear puller has to hold on to something, one specific to a specific grinder would do the least damage. If you use appropriately sized picks and brushes, it isn't difficult to clean a grinder without pulling the lower carrier, but that's sort of where this thread began.

August 12th, 2020, 3:27 pm

Thanks for the responses