# Checking run-out on lower burr / carrier



## El carajillo (Mar 16, 2013)

The run- out was only 1 thou, ineligible really. I did correct it by placing the burr on a piece of shim steel (on a smooth surface) and drew a scriber around the burr, moved the burr about 3 mm and scribed another line. This gave me a curved piece of shim the same width as the seating rim on the burr with this in place and burr re-fixed no run-out.

I then checked from burr face to top carrier shoulder, this showed no difference around its perimeter:good:

As the top burr carrier has some lateral movement, my next task is to find a way to overcome this play.

















NEED MORE COFFEE


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## ajohn (Sep 23, 2017)

Interesting. One of the video's that are around mentions that on their commercial grinders the grind chamber comes as part of the motor. Also that they use a spring washer to tension the top bearing correctly. The same ideas seems to be used on all that have the removable top plate.

I'm a cheap skate looking at a 37J. One thing I do like is how they have located the top plate - countersunk headed screws. I did wonder how they got round the problem of locating that before I bought it. It's a technique I sometimes use when making things myself. Best do 2 stage tightening to allow it to work correctly. The conical section on the base of the head of the screws will pull things into alignment so it should always go back on with the same alignment. Accuracy depends on how precise the plate holes and threaded holes are positioned relative to each other and the actual burr carrier.

John

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## El carajillo (Mar 16, 2013)

I can not speak for the cheapskate version but on the one I have the grind chamber is not part of the motor.

The top plate is located by machined shoulder, the screws only locate it circumferentially.

The spring washer is to hold the lower carrier to the shaft / spindle as it is not keyed to the shaft.


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## ajohn (Sep 23, 2017)

Try this from 8 mins - it also mentions the spring washer - internal to the motor to preload the bearings.

[video=youtube;k3_wYXzXF-w]






Screws - well I tried.







:good: can't really do more than that.

John

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