Replaced failing bearings on mill

[shoengine]

I noticed that my rollers weren't rolling properly and after disassembling the mill, the four bearing sets were just barely functioning. Fortunately the part numbers were still visible so after some searching I found good looking replacements. I did make one change though. The originals were single shielded bearings and I swapped them out for double sealed bearings. There is a lower RPM tolerance for sealed but since the mill runs at such a low RPM anyway I decided I didn't care.

You can see significant damage from the roller contact with the soft aluminum block. Getting the bearings out of the blocks were simple, I just inserted a brass drift into the rear of the block and tapped them out. The rollers were another issue. We ended up rigging a puller out of a vice and a couple nails and with a slide hammer got them out.

Pressing the new ones in was painless.

Hopefully this fixes my problems I was having.

 

[shoengine]

Crunchy

 

[Broken Crow]

Reminds me of the jack-shaft bearings on an early mini-bike I built as a kid and rode through the mud quite a lot!

 

[shoengine]

Reminds me of the jack-shaft bearings on an early mini-bike I built as a kid and rode through the mud quite a lot!

Ha, that would have been a blast!

The races look pretty crummy too.

The real victim of the BIAB trend!

 

[sbro]

How old was that mill and how much use did it have?
Not too hard maintenance but I am wondering how often this may be needed.

 

[shoengine]

I couldn't answer. I bought it used off the forum a couple years back, and I perform a fairly fine crush since I use it for BIAB. To me it was obvious something was wrong due to the rollers not moving freely. I wouldn't worry about it unless you notice something is off.

 

[sbro]

from the pictures, it may have been cleaned with water forcing some wet fines into the bearings to corrode.

 

[shoengine]

from the pictures, it may have been cleaned with water forcing some wet fines into the bearings to corrode.

Yeah, I'm not sure if it is flour mixed with the lubricant or something else. I'll have to taste it and see if it tastes like old grain or rust

 

[sbro]

What flavor was your bearing? A bit crunchy!
Borrowing a friends hull wrecker mill for a couple brews and it is only about a year old. Bearing on the drive roller is very noisy compared to the idle roller which sounds like new. I can feel a very slight play in the shaft and see a little rust in spots which tells me he has washed the mill. Most likely going down the road yours did but still good life left. I am guessing there is no way to oil the bearings as they should be sealed.
This just shows how important it is to not get these things wet.

 

[sibelman]

how important it is to not get these things wet.

This confirms the deep wisdom in my failure to clean my mill more than once or twice a decade.

More seriously, it makes me worry a bit for those who are moistening their grain before milling.

 

[day_trippr]

More seriously, it makes me worry a bit for those who are moistening their grain before milling.

I've been conditioning malt for years but to date haven't had milling problems related to bearings. That said, my first mill (BC) was bushed and I expect one could literally dunk that one without repercussions. Ran over 3000 pounds through it before reversing the rollers and now use it for just oats, wheat and rye so I can leave my 5 year old Cereal Killer barley gap untouched. The CK mill does have ball bearings - "sealed", fwiw - that so far are still quite smooth and run without any hiccups.

Conditioned malt should be barely damp, never wet...

Cheers!

 

[shoengine]

You can confirm if they are sealed, shielded, double shielded or double sealed by the part number and inspecting if each side is the same. When ordering the P/Ns end with:

Z = shielded
ZZ = double shielded
RS = sealed
2RS = double sealed

Mine were all ZZs. Also, I never used any liquids with my mill, but it certainly could have been before I bought it.