Duranium burr installation

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jwCrema
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#1: Post by jwCrema »

I'm giving Duranium burrs a try in my SJ. During the replacement of the burrs, I discover that the mount screws are at least 1mm smaller than the holes in the burr. I'd imagined the burrs used a tapered screw head and I'd use a normal cross pattern tightening technique. The original Mazzer burrs are completely the same as the Duranium burr as far as the screw hole sizing is concerned.



This is a picture of the original Mazzer burr. From the old grounds you can see it was not aligned with any precision on what I'll describe as the X-Y axis, which is how the burr rests on the drive plate. The Z axis represents the distance between the top & bottom burr.

I installed the Duranium burrs with far greater precision than the factory did. You can see how unaligned it was by the gaps in the screw head recess. Does anyone care about this? I am considering remounting the Duraniums with a Teflon sleeve on each screw to reduce the (astounding in IMHO) slop that's otherwise possible.

From a taste perspective, ran out of beans at the same time I did the swap, so I lost my control shot. The new shots are fricking tasty, so I'm not unhappy with the upgrade.

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dsc
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#2: Post by dsc »

The issue here is that you are assuming the mounting holes are machined perfectly in relation to the axis of rotation of the burr mount. It is possible that is not the case and the reason for the slack in the burr holes is to address this, it gives you enough room for maneuvering the burr and getting it perfectly aligned in relation to the axis of rotation (which is really what you want to achieve here). We don't know what the assembly procedures Mazzer uses to mount their burrs, it is quite possible they have special tools which allow them to mount the burrs perfectly without having to faff around with shims or other methods home users use.

As I said before, make sure your point of reference for aligning (burr mounting holes in this case, or typically machined edges on burr mounts) is good enough to make the whole exercise worth while, otherwise you are aligning to something which might be way off to begin with.

T.

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jwCrema (original poster)
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#3: Post by jwCrema (original poster) »

Thanks for this Tom. I have a way to measure that - will open it up after the morning cups and take some measurements.

F1
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#4: Post by F1 »

Who sells the duranium burrs for the SJ? Anything better about them compared to the original burrs?

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dsc
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#5: Post by dsc »

jwCrema wrote:Thanks for this Tom. I have a way to measure that - will open it up after the morning cups and take some measurements.
No worries, easiest way would be to clock the outer edge of the burr with a DTI whilst the burr holder is rotating on a well fitted shaft / rod. In this case you are assuming that the burr is perfectly round though, which might not be the case (although from the burrs I've tested is the case).

T.

jwCrema (original poster)
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#6: Post by jwCrema (original poster) »

I decided to give Duraniums a shake after reading this test: Titan Grinder Project

I got them here: https://www.espressocare.com/products/mazzer-grinders