Last night I started the reassembly of my Rio/Mazzer SJ and started with the lower burr carrier. For those who have removed and replaced it know there is a pin that runs through the spindle and that the placement of the lower burr carrier has to be just right. The lower burr carrier is a tight fit on the spindle as well.
Once I felt I had the lower burr carrier on, I added the upper burr carrier and as mentioned above it can be tricky. I ultimately won that battle and got it screwed on.
When adjusting the grind to a finer setting, I'm not entirely sure if it screws down as far as it did when I received it. I'm kinda wondering if the lower burr carrier isn't on all the way. I really torqued down the lower burr retaining bolt and looking through the grind chute it appears that there isn't much space between the bottom of the lower burr carrier and the top of the grinder well. Anyone know what the clearance should be?
Is there any trick to make sure that the burr carrier is properly seated? The grind seemed powdery at the setting a touch above where the burrs touch. I'm also afraid that if its not properly seated my grind quality will be seriously compromised.
I know I'm reviving an old topic, but I've just experienced this exact same thing on my Mini E. I bought the grinder used and wanted to take it apart for a thorough cleaning. I used the 3-screw method for removing the lower burr carrier, and after scouring the thing, I placed the carrier back on the shaft. I took care in seating it according to the shaft pin, screwed the center bolt in, and all seemed fine after a quick visual inspection and actual test...no rubbing, squeaking, or anything out of the ordinary. However, when I put the top burr assembly back on, I checked the zero-point, and noticed that it had shifted significantly...instead of being at (or near) "0" on the adjustment collar, it was now around 7.5, and the reference sticker was now toward the back of the grinder.
Oddly enough, it still seems to be grinding ok. Although, just like Mike, I couldn't help but notice how high the carrier is sitting off the chamber floor (I noticed it too when looking in through the chute). Consequently, the adjustment collar also seems to be sitting abnormally high, as my dialed-in grind is now somewhere around 8.5, when it was round 1.5 before.
As I always do, I searched the forum for answers; I found this thread
and I'm a firm believer that somehow, I've raised the entire motor assembly out of the bearings a bit. I'm considering trying coffeemelon's solution, but I'm a little uncomfortable hammering anything other than a nail (or anything that I'm not intentionally trying to break for that matter). Any suggestions?