Careful ordering I ALMOST ordered with RUBBER shields !
I would be pretty hesitant to use some of the stronger cleaners - coffee cleaner or PBW (powdered brewery wash) - on bearing steel. It might do more harm that good. Pure ethanol or a degreaser designed for the material is probably better. If you have the ability to do an ultrasonic bath, that may be necessary to really get gunk loose and out of the bearing.
Good to know the bearings are widely available, and so replacement is probably just easier instead.
So I was cleaning my Bullet today and the front bearing rolled somewhere and I canât find it. Do you have the specifics of the size of that bearing so I can find a replacement?
Itâs like 5 posts above yoursâŚ
Any suggestions on remove the bearing? Mine wonât budge and Iâm not sure what tool would be appropriate in this setting.
Mine just slides off easily.
Not sure if beneficial to the discussion or not but Iâll add my experience.
I am less than 200 roasts in and have a âgunkyâ bearing. I have a feeling it is because I dropped it into my sodium percarbonate solution and it did some damage to the bearing. I did buy some synthetic, food grade oil to see if I can clean it out. Based on a Sweet Maria cleaning guide that Iâm sure everyone here has seen - you can use a q-tip with some alcohol. Might help?
The percarbonate is AMAZING for removing crap off the chaff filter⌠but might be too heavy for bearing.
I also bought some bearings in my same purchase as the oil so I can use a replacement while I try cleaning out the old one.
The original is a 6900Z.
I donât know the difference between 6900z and 6900zz but I had to be careful when shopping around Amazon to get âzâ. I found them for about $2.50/bearing⌠cheap enough! Here is what I bought and it is working well - [Amazon Link] (https://a.co/d/2WrrNGn)
Not the cheapest on Amazon but as Iâm sure you are aware⌠gotta balance ratings, Prime, and confidence level that you will actually get the part you want and not âzzâ ⌠in case there is an important difference. Again, anyone know what that is?
More than you ever wanted to know about that front bearing. Got this hit on Google search-
" The 6900Z ball bearing is a single row raceway and single shielded. The 6900ZZ ball bearing has a single row raceway and it is shielded on each side. "
Dunno if they are interchangeable but it seems possible so long as the 2nd shield doesnât keep the bearing from seating completely- that would be the open side of a âŚZ bearing and should face away from the drum; itâs the side pressed into the face plate. They didnât include a dimensional dwg of the âŚZZ so Iâm doing some guessing here.
The listing I got on Amazon for the 6900Z includes a description which says the bearing has a double shield. Properly itâs the âŚZZ which has the double shield. They have 7 images and none of them confirm a seal on one or both sides of the bearing. $11.XX for 10 bearings sounded cheap enough to give it a try. Iâm guessing the single shield was chosen to allow better heat loss from the open side of the bearing during a roast.
Bruce
Edit- the issue with Amazon is that youâll see a different price each time you search as they rotate thru the available sellers.
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Should be no problem substituting the ZZ bearing for the Z.
IIRC, this is the same bearing size used on virtually every skateboard wheel, so they are made in large quantity and generally very cheap.
-Gray
@bab - this is awesome. Though, after looking at my original and new bearings I donât see one side shielded or looking any different than the other. The photo below shows the only difference between my new bearings and my old is the âNBNâ or âN8Nâ (not sure which) on the original. I have shown âboth sides of my new 6900z on the bottom half. Though, I canât possibly know which is the front or back because they are the same!!
So how is a 6900zz (double-z) different!? Haha
I have no clue what the original Google hit was describing in terms of what you have here- perhaps a discontinued option. The bottom line is you have the 6900Z bearings so just go for it.
Bruce
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Figured. Just thought it would be worth noting. Maybe someone in the future will be racking their brain about this and can find the answer here.
For the front I use SKF F61900-2Z and rear the SKF 61900-2Z.
I think in US the front bearing are called W61900-2Z.