Stevebcoffee wrote:I'm a complete newbie with this 3d printing malarkey but I am good at finding a way. Once I get to embed the square nut I could either send the revised files or the printed parts, at cost plus postage. It's a few specific nuts, 12 magnets and the prints themselves are peanuts.
Might take a week or so to get Fusion 360 to do what I need though. I'll post a few pics of what it looks like. Totally reversible in a few minutes as well

Looking forward to hearing more of your impressions once the burrs settle in. I'd likely be willing to purchase a set of parts from you if you decide to go that route!

Few pics of the finished mod. Works well from espresso to pour over. Am making 2 changes for version 2.
Reducing the height of the modded parts by 1.5mm which will give me another 3 revolutions of adjustment - plenty for even french press and above.
Also changing the hex nuts that are used to hold the burrs in place to square which are better for this application.
So far, at espresso, the shot times are very consistent on the Decent and 45 seconds for 21g is not much effort

The black looks much better than the pastel colors the guy in the video used.

Does the magnet rim overlap the burr or is that just a weird camera angle?

Have you noticed any differences in shot quality compared to the 71mm?

Thanks so much for all your info!

There is a ledge where the stainless cup fits. Directly below that it chamfers 45 degrees to outside the inner burr if that makes sense

Didn't really use it with 71 as I have a Niche. Way more clarity on fruity or light coffees than the Niche. As I've said maybe the VERY slow speed makes a difference.

Hi Ken, can you elaborate why the alignment is not very precise this way? Is there a better aligning method for it?

bakafish wrote:
It is not that easy to align the outer burr. The easiest way is using the inner burr to lock the outer burr and then tighten the 3 screws, but you have to gradually lock the burrs, not straight down. I dialed the inner burr to slightly rub the outer burr, and then rotated the shaft or handle to use the inner burr to push the outer burr, slightly tighten the screws, dialed to finer and finer, repeat these steps to fully locked and tightened the screws.

I don't think this method can get the very precise alignment, but good enough.

cuongdinh wrote:Hi Ken, can you elaborate why the alignment is not very precise this way? Is there a better aligning method for it?

When you use the inner burr to lock the outer burr, there must be somewhere of the inner burr rubs the outer burr more and the opposite side rubs less. So I recommend the following steps:
1. keep the outer burr loose
2. dial to the burrs touch
3. rotate the inner burr to push the outer burr
4. slightly tighten the screws of the outer burr
5. dial to finer
repeat step 3 to 5

When the screws are tightened to some degree, the outer burr is still not fixed firmly, but cannot be pushed by the inner burr. Now you can dial to lock the burrs and fully tighten the screws. The alignment is not very precise but good enough. If you can find where the burrs rub more when the outer burr is not totally fixed, you can knock the outer burr from the side to adjust its position. Sometimes you can find the rub disappears, which means you have a better alignment.

I won't overthink it and will add that when I aligned mine, even though it was seemingly fine since new, I gave it a deep cleaning to be sure things would be as accurate as possible. When tightening the screws I would tighten a bit, then spin the burr after tightening the adjustment a bit to keep things centered, tighten the screws a bit more, etc. and used a precise inch/lb torque screwdriver. I wasn't looking for any particular torque spec as there are variables involved in that alone, but tightened until it felt firm to my hand then repeated that torque value to all 3 screws a bit at a time. For example, I tightened screw A to 5 inch/lbs, then screw B and finally C. Then went back to A and torqued around 10 inch lbs, etc. Ended up applying about 15 inch lbs to all 3 screws as that felt quite firm to me and with heavy daily use nothing has budged whatsoever. With the burrs clean when fully locked down the burr will still spin slightly with no rub at all, so I imagine the alignment is about as good as it can get and that works for me...

I will also add that regardless of claims of ceramic burrs being self-lubricating, periodically I still tear the thing down, clean both shaft bearings with 91% rubbing alcohol, let dry and apply a few light drops of a quality synthetic bearing oil. My preferred favorite is TSI 321 as I use it for other quality/precise items as well. Then reassemble paying attention to the bearing load and it really gives a silky smooth feel to an already great grinder. In stock form a bit of coffee dust will make its way into those bearings and give a bit of gritty feel over time. Likely won't cause any real wear due to being quality ceramic, but a bit of effort as described can really smooth things out. In stock trim one shield from each bearing has been removed and that makes keeping them clean a breeze due to very easy access.

Been using my 106 pretty much daily for well over 1 year and put about 2 lbs. through it weekly for espresso and it still continues to impress. The burrs are rated for 1,700 lbs and that is clearly for a commercial environment where constant use/heat is a factor. In a home setting grinding manually I have no doubt the burrs will last my lifetime. No concerns over stones, etc. as I home roast and inspect every batch many times over... I did recently buy a few extra parts to have onhand for possible replacement in the future (if ever actually needed) and for those looking for the ultimate (especially compact) hand grinder the 106 likely stomps them all.

Thanks, Ken and Bodie.

bakafish wrote:When you use the inner burr to lock the outer burr, there must be somewhere of the inner burr rubs the outer burr more and the opposite side rubs less.

I don't necessarily agree with this. Since the outer burr when loose can move quite a bit 'horizontally' (perpendicularly to the shaft), we can always find a position where its output face is perfectly concentric with the inner burr's, except for the fact that they are not perfect circles. I think the keys to find that position is (1) to clean the burrs thoroughly in advance, as Bodie mentioned, to remove any potential coffee particles pushing the burrs off center (2) push the inner burr deep into the outer as much as possible to the point they lock. This can be repeated by wriggling the outer burr pushing the inner to find the deepest position, like

bakafish wrote:If you can find where the burrs rub more when the outer burr is not totally fixed, you can knock the outer burr from the side to adjust its position. Sometimes you can find the rub disappears, which means you have a better alignment.

After that, I'd just tighten the outer burr screws as Bodie put

BodieZoffa wrote:I won't overthink it and will add that when I aligned mine, even though it was seemingly fine since new, I gave it a deep cleaning to be sure things would be as accurate as possible. When tightening the screws I would tighten a bit, then spin the burr after tightening the adjustment a bit to keep things centered, tighten the screws a bit more, etc. and used a precise inch/lb torque screwdriver. I wasn't looking for any particular torque spec as there are variables involved in that alone, but tightened until it felt firm to my hand then repeated that torque value to all 3 screws a bit at a time. For example, I tightened screw A to 5 inch/lbs, then screw B and finally C. Then went back to A and torqued around 10 inch lbs, etc. Ended up applying about 15 inch lbs to all 3 screws as that felt quite firm to me and with heavy daily use nothing has budged whatsoever. With the burrs clean when fully locked down the burr will still spin slightly with no rub at all, so I imagine the alignment is about as good as it can get and that works for me...

I'm trying a self-cut, thin layer (0.7mm) of silicone washer between the outer burr and the body. Idea is to be able to tilt the outer burr in relation to the body by differentiating the torques on the screws, to ensure perfect alignment between outer burr's and the body's, if necessary. Not sure what 'perfect' is though.

BodieZoffa wrote:I will also add that regardless of claims of ceramic burrs being self-lubricating, periodically I still tear the thing down, clean both shaft bearings with 91% rubbing alcohol, let dry and apply a few light drops of a quality synthetic bearing oil. My preferred favorite is TSI 321 as I use it for other quality/precise items as well. Then reassemble paying attention to the bearing load and it really gives a silky smooth feel to an already great grinder. In stock form a bit of coffee dust will make its way into those bearings and give a bit of gritty feel over time. Likely won't cause any real wear due to being quality ceramic, but a bit of effort as described can really smooth things out. In stock trim one shield from each bearing has been removed and that makes keeping them clean a breeze due to very easy access.

Take care of it and it'll serve you well . What do you mean by « paying attention to the bearing load »? Does that mean how tight the bearing locking nuts are?

BodieZoffa wrote: Been using my 106 pretty much daily for well over 1 year and put about 2 lbs. through it weekly for espresso and it still continues to impress. The burrs are rated for 1,700 lbs and that is clearly for a commercial environment where constant use/heat is a factor. In a home setting grinding manually I have no doubt the burrs will last my lifetime. No concerns over stones, etc. as I home roast and inspect every batch many times over... I did recently buy a few extra parts to have onhand for possible replacement in the future (if ever actually needed) and for those looking for the ultimate (especially compact) hand grinder the 106 likely stomps them all.

Agreed for the most part, except the stone inspection . I try to do the same but can't be sure to not miss some tiny stones hidden in the beans.

BodieZoffa wrote:With the burrs clean when fully locked down the burr will still spin slightly with no rub at all, so I imagine the alignment is about as good as it can get and that works for me...

Do you mean the inner burr and outer burr without screws still can spin with no rub when fully locked? I don't know how could it be though I am not using the Mazzer burrs.

cuongdinh wrote: I don't necessarily agree with this. Since the outer burr when loose can move quite a bit 'horizontally' (perpendicularly to the shaft), we can always find a position where its output face is perfectly concentric with the inner burr's, except for the fact that they are not perfect circles.

Maybe you are right. I am not using the Mazzer burrs. My inner burr cannot fully go into the center of the outer burr.
This is it.

The burrs surface are not smooth or glossy enough to let the outer burr slide away when the inner burr goes in and touches the outer burr and the outer burr may be stuck there. I had tried so many times and the alignments were not good if I directly locked the burrs from beginning.

cuongdinh wrote: What do you mean by « paying attention to the bearing load »? Does that mean how tight the bearing locking nuts are?

Agreed for the most part, except the stone inspection . I try to do the same but can't be sure to not miss some tiny stones hidden in the beans.

Correct as a bit too snug and you will feel friction when spinning the shaft by hand... too loose and there tends to be a bit of play, just right and it spins nicely with no movement whatsoever. Once I get those 2 parts secure I mark with a Sharpie just to keep an eye on it to be sure things don't move during use. So far the lock nut stays exactly where I leave it.

I look at the green as I pour/weigh each batch... then watch closely during the roast process... then look at the roasted coffee as I transfer it to a colander... then again when I scoop it into a jar and once again when I weigh/dose for each use. Great thing with a hand grinder is if there is any sort of dense debris it should be easily felt.