Just as I was reaching ristretto nirvana with my Pharos and La Peppina, my grinder decides to go out of whack

So I spent all day taking it apart and putting it back together. Over and over, and I thought it had it perfectly tuned to try this morning. Well, used some freshly roasted beans (light roast) and it got out of whack.

I think it's time for some fresh ideas on the Pharos specifically with the VD mod. Here are the questions I am having for those who use their VD-Pharos as an everyday grinder:

[?] how often do you need to realign it?

This is the first time since I got the VD mods that I have taken it apart and I got the grinder in May.

[?] how tight do you set the screws that hold the thumb nut?

I find that tightening the 3 screws too tight changes my setting and too loose with my hard beans has it slip during grinding. What's the goldy locks zone?

[?] have you tried the 4 screws that hold the outer burr both tightened (this is how Will sent me the grinder after the installed his mods) and loose (how Doug does it on his Tech bulletin videos)? Which do you prefer?

[?] can people post pics where their 0 is (on the acrylic scale) and the general range for their espresso grinds?

My general thoughts are to just watch Doug's videos a few times and then do as he says. Take it apart and put it together until you become one with it. Okay, now that I have tools this is pretty fun and every day I am reminded of just how ingeniously designed the grinder is. So even though I might sound like a dissenter and trouble maker, I really love this grinder.

Edit: here's some pics from two different shots. One is tamped the other is not. yikes.

I also have the modified pharos. Initially, I also encountered the same problem with you that the grinder arrangement went wrong after light roast. What I did was I adjusted the burr by knocking the plastic tube little by little so that the burr did not touch on all side at 1/4 turn, then I tightened the 4 screws (against Doug recommendation) then the 3 outer screws tight while making sure the burr was still aligned properly. I believe the tightening prevent burr misalignments. Sometimes I tighten the burr to 1/4 and check the burr alignment and so far so good.

I also found that if the burr is properly aligned, the turning force required is less if the burr is misaligned. Logically, if it is misaligned, there will be sections where the gap is narrower and therefore require more force.

Good luck on your adjustments.

Hi Riady, thanks for the reply and encouragement. I follow a pretty similar alignment, but I'm pretty frustrated since this thing just doesn't want to behave.

I give up, I'm gonna use the Hario Mini for a few days. I feel like the resident grouch since my equipment just doesn't want to behave.

I have never seen a VDD modded Pharos, so I can't advise on how to bring it back into service, but let me add that not only is it critical that the components be aligned along the vertical axis..the outer burr centered in relation to the inner but all of the horizontal surfaces must be parallel to each other so as not to "tip" the outer burr off planar in relation to the lower surface of the inner burr. In the original Pharos design the 3 large bolts act to allow the plates to compress the central cylinder together...the lower ABS, the burr, the upper polycarbonate...these 3 components are pressed together by the plates to form the central aligned core of the machine. The original PVC bolt covers have enough compressibility that they will not produce off planar compression of the plates and central core...Barb spends a lot of time with a flat bed sander and caliper making sure the ABS and polycarbonate cylinders are precisely square with parallel ends to eliminate any out of planar effects which can screw up my ability to align along the vertical axis when I build the grinder. Since from my understanding the VDD build substitutes stainless steel bolt covers that act to hold the plates together and cover the bolts but have no other function. I do not know the tolerances VDD is working with but if one of these covers was out of tolerance a small amount this could put at least the top plates out of parallel and tip the burr...but again, I know only my trials and tribulations involving the original Pharos....the most under engineered precision device I know of.

I never liked the idea of shortening the shaft because it was apparent to me that having the bearings close together would make alignment more difficult, and I have never had any problem getting the ground coffee out of the machine when I took measures to prevent the ground coffee from forming a sort of Igloo over the opening. (I simply made an extension to the stopper to accomplish this.)

I did like the idea of replacing the spacers because plastics suffer from creep over time and it seemed to me it would be better to replace them with metal ones for long term stability. I thought aluminium to be the best metal because it has lower moduli than things like steel and stainless steel. My approach was to use an inside micrometer to measure the distances between both plates. I measured in several places, and they were remarkably parallel on mine!

I cut 7 pieces of round aluminium bar stock to slightly longer distances than the distances between the plates and drilled 6 of them to match the diameters of the 3 bolts that hold the machine together. I drilled and tapped the 7th to accept 8mm screws, I believe it was. Then I took the drilled and tapped one and three of the drilled ones and faced them down to the average length that I had measured for the distance between the top and middle plates. This took me a long time because I tried to make them to within 0.02 millimetres. Then I took the remaining 3 and faced them to the length between the middle and bottom plate to the same precision. (I accidentally faced one down too much and had to cut another and then drill it. It is easier to take metal off than put it back on.)

I used the seventh spacer, the one I had drilled and tapped) to provide a handle using the holes in the plates designed to carry the adjustment too.)

Anyone doing this should note Doug's advice that these spacers must be cut to very precision length. Because aluminium is less flexible than plastics, it is my opinion that the spacer length should be the distance between the plates in the assembled pharos, rather than the length of the plastic spacers.

At any rate, what I did resulted in perfect alignment. I think others doing this should heed Doug's advice about the imporance of having the plates parallel. The axis of the bearings must be exactly parallel as well. Nothing can be off centre. Precision really is required here or problems seem certain.

Thanks Doug and Robert for sharing your thoughts. I think the inner burr and shaft are perfectly aligned but what I cannot get perfectly centered is the outer burrs. Of course, the frustration comes from not being able to pull good shots and knowing just how good this grinder is when tuned properly...but playing with the grinder and thinking about how it works is fun.

Good news is, taking it apart and putting it back together yesterday, I am really close to having it in service again. Dialing it in now. I found that holding the outer burr was a bad thing when grinding hard beans since the forces exerted were too much for the grinder to handle and it would get out of whack mid grind. So, lately, I've been using a c-clamp on the edge of the counter and holding the Pharos only by one bolt cover opposite the c-clamp (right-most). I think having SS bolt covers and the extra long handle are essential here.

I would think that holding the Pharos whilst grinding by the stationary burr would exert forces on it and would easily result in the thing becoming horribly misaligned were it to slip.

Another thing you might consider doing to hold it whilst grinding is to place a drilled and tapped metal rod between the upper and middle plates in the holes designed for the adjustment tool. It must be cut to precision length, the same as the upper bolt covers, however, or it will certainly mess up alignment. Then you could hold it by this rod and one of the adjacent bolt covers. You could also instead use a piece of hardwood.

Here is a picture with such a metal rod in place.

A week with Pharos 633

beer&mathematics wrote:Dialing it in now. I found that holding the outer burr was a bad thing when grinding hard beans since the forces exerted were too much for the grinder to handle and it would get out of whack mid grind. So, lately, I've been using a c-clamp on the edge of the counter and holding the Pharos only by one bolt cover opposite the c-clamp (right-most). I think having SS bolt covers and the extra long handle are essential here.
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Interesting. I have a stock Pharos and tried a clamp but my concern is the clamp screws up alignment because you are pushing straight down on the handle all the way around but the clamp is compressing the lower disc in one spot to the counter. The feet are spongey so at some point you are going to be levering against the clamp pulling down at that one place.

More good news as the grinder is back in action. I have my coffee dialed in (Grumpy's Heartbreaker) but not without some small burr rub. I am just going to enjoy the coffee for now and not worry about it

About how to hold the grinder. With medium to dark roasts, I find the forces to be pretty small and can hold it how ever I want with good results. With really light roasts (think City roasted on a popcorn popper), the forces are extreme and how you hold the grinder is important. Although holding the bottom with the c-clamp is asymmetrical, this method produces best results provided the setting doesn't slip (which is still a problem for light roasts).

What would really help distribute the force evenly is to modify the original OE stabilizing pad to fit the bolts and new feet of the VDD base. Now that I have a dremel I enlarged the holes so that the feet of the VDD mod fit into it. I also started to drill holes to fit the nuts on the ends of the bolts but I didn't make them deep enough. Once I get the time to finish this properly, I'm sure it will help.

I always found that tightening the bolts almost all the way, checking for rub and then using the wooden mallet to tap the outer burr into alignment worked best. I takes a bit of fiddling but with this I get to about an 1/8 of a turn before it rubs. I also locked the burr in place because I had some issues with drifting when holding it. 8 months and I have had no need to adjust the alignment.