This document will generally follow the Lido OG basic manual and expand on some concepts of the grinder and hand grinders in general for those who may be interested....
Parts of the Grinder
For the overall design and construction of the OG we have returned to our original Pharos/Lido 1 concept...creating a simple and functional machine to grind coffee. Almost all of the parts of the grinder are CNC machined to assure precision. This approach also allows flexibility to change or modify parts going forward if the need (or whim) arises. Major body parts are machined from aluminum and anodized. The hopper has a full silicone grip (hand grinding is much easier with a good non cranking-hand grip).
One major design element is the side fill bean port. We first used the side fill concept on our Fixie Travel Grinder and it proved be an acceptable design. On a hand grinder one has limited real estate to work with, and in general current cylindrical format hand grinder have the adjustment mechanism either below the burr in the grinds chamber, or on top of the grinder on a threaded axle. A top adjustment may be favored in many designs but this system must be miniaturized or simplified to allow space to pour in the coffee beans. By moving the bean port to the side we are able to secure a large area to do something interesting with...in this case a dual adjustment system, which is one of the strongest features of the grinder.
The design decisions on each part of the grinder has involved maximizing the potential of the part as it integrates into the whole and how it provides specific function for a modern hand grinder. For example, the grinds jar is made of double wall stainless steel. The double wall construction allows a smooth inner wall with no lip inside to catch coffee grounds. The uncoated metal results in the most effective static dissipation...we are not big fans of spraying water on the beans and therefore on the steel burrs... (glass is also good in this regard but it is: a) breakable and b) standard jars all have an internal lip/shelf which gathers coffee grounds and traps a certain amount of coffee). So in this example we have tried to consider all aspects of the particular part and optimize--but these pesky trade offs always creep in to the design process (the stainless jar can be dented after all and is expensive to manufacture...trade off after trade off).
Another example of the optimization of parts of the grinder is the use of brass for the stepless micro adjustment disk. We went with this material to avoid the possibility of thread galling on the stainless steel axle. Stainless steel is cheaper but then we risk thread galling. Aluminum is the cheapest, but too soft to deliver a lifetime thread. Aircraft aluminum is very hard, especially when anodized, but right now (year 2021) it is in short supply and the price is increasing daily. Even though the brass can scratch or mark easily, it supports cutting a beautiful 0.5mm thread and we will just call the tarnish PATINA!
While I am on the subject of parts, let me say a few things about handle length....we use a fairly short handle on our Lido series grinders...the operative length is about 4". Some people assume that a longer handle gives more power and therefore more speed. In a sense this is true, if you follow the analogy of using a longer lever to move the world, but a longer handle has certain drawbacks. Foremost is that the more power you deliver with the cranking hand, the more power is needed to counter this force with the holding hand. Our Pharos grinder tears through beans at about 1 gram per second and the hardest thing about grinding with the Pharos is the strength needed in the holding hand. It is actually pretty easy if the grinder is bolted down to a counter but otherwise the holding hand does a lot of the work. We have designed the Lido grinders to be used with a two handed spinning motion....one makes small circles with each hand...one can actually almost hold the handle hand still and just move the body hand. Also we use a base supported approach with the body of the grinder resting on the jar and held at a 30 degree angle while turning with both hands in a sort of cyclonic motion. This approach allows one to turn the burr with the highest RPM, if that is your goal and result in faster grinding times. By using a longer handle, one also uses a lot more shoulder movement to ascribe the large loopy turns. Our overall design allows one to use the grinder with mostly wrist and elbow movement while minimizing the use of the upper body...this may become important to you after hand grinding for 10 years or so. The grippy silicone hopper cover also helps reduce strain in the holding hand. As ambassadors of hand coffee grinding we have always tried to debunk many of the myths of hand grinding...too slow, too difficult, tedious, Popeye arms, for big strong guys, what a workout, etc, etc. We feel that our design of the Lido OG debunks these myths and removes many of the barriers to entry for people who want to just grind some coffee by human power.
Grinding Burrs and VBM
All of the parts of the hand grinder are basically a frame to hold the burrs and a method to turn the burrs. So what about the burrs, which after all, determine the performance of the grinder... speed, required turning force, grind distribution, espresso vs brew grinds...so let's just agree that the burr is really important. One thing to consider when thinking about hand grinder burrs is that these burr sets were (are) designed to be used in electric grinders. Most are standard run burr sets, small conicals, that are generally used in small home grinders, grind to brew machines, and some super automatic machines. Design considerations are therefore motor size, serviceability, grind speed, longevity, etc but when used in a hand grinder many of these considerations fall away and the factors of speed, required turning force, and most importantly, results in the cup become more critical than the other industrial concerns.
We have experience using 5 different burr sets in our hand coffee grinders over the years. I want to address only the conical burr sets and try to shed a little light on the subject and hopefully clear up some misconceptions When one reads that the "X" grinder uses a "Y mm" burr set keep in mind that this number is the outside diameter of the major dimension of the ring burr. This number is the OD measurement of a circular ring burr or in the case of the Etzinger burrs we use (and similar Italmill burrs), the flange or shoulder section of the ring burr. This nomenclature is industry standard. Here are the actual measurements of the 4 conical burr sets that we are intimately familiar with:
Due to the industry method of designating ring burr size the numbers can be misleading when the major dimension includes a flange or when the body of a ring burr with no flange is quite thick. When comparing the machines internal portion of the ring burr and the major dimension of the cone burr these burrs are all nearly equivalent in size. The performance differences are in the machining of the blades in the different sections of the burr sets. We can compare and address the differences between the Italmill "48mm" burr set and our Etzinger "48mm" burr set and how these design approaches relate to the performance of our grinders.
A top view of these two burr sets shows a stark difference between the two. Let's call the top portion of the burr area the crushing zone where whole beans are broken into smaller fragments to enter the intermediate cutting zone and finally into the zone of smaller grooming teeth (or blades) for the final result. These two burr designs represent the two major design approaches for conical burr systems. The large Italmill crushing system supplies a lot of material into the lower blades of the system quite rapidly. The material is pushed through the blade system by the the impeller action of the conical burr. This type of burr requires a larger motor (or arms) and is fast and aggressive--high throughput with a lot of torque required to process the coffee through the system.
The Etzinger design (and other similar) have a less severe primary crushing zone allowing a smaller motor ( less arm force) and therefore grind times to process the same amount of coffee are longer. The Etzinger style burr feels more like "milling" when used in a hand grinder whereas the Italmill design has more of an attack and explode feel. "Feeling" may be too subjective a measure of performance but feelings do matter. The power required to turn the more aggressive burr for some people is excessive, especially in the espresso range and does cause many people to suffer greatly (myself included) so that's another thing...
A second area of burr design and the one most critical to our adjustment system approach with the Lido OG involves the design not of the input, but of the output end of the burr set. Besides the obvious differences in blade size, geometry, and numbers, I want to focus of the final machining of the edge of both the cone burr and the ring burr. On both the Italmill and the Etzinger cone burrs there is a final machined edge around the circumference of the burr but the machining of the final edge of the ring burr is critical to our grinder design. The small blades of the Etzinger ring burr terminate AT THE PRECISE EDGE of the ring burr while the Italmill ring burr has about a 1mm machined bevel leading up to the edge.
When the cone burr "nests" inside the ring burr it will turn generally smoothly with no blade gnashing (best on a well broken in burr set) due to the presence of these machined edges and bevels. As the Etzinger burrs begin to move apart (in our case with the cone burr moving vertically) in a well aligned system the burr gap immediately becomes large enough to grind coffee...at about 150nM vertical burr movement (VBM). At this VBM the burr gap is quite small but will grind and feed fairly efficiently at a VBM of 200nM.
On the Italmill burr the larger machined areas on both the cone burr and the ring burr and the extreme nesting fit of the two burrs is good for a smooth feeling at zero (burrs touching) BUT the with this design the Italmill cone burr must move vertically in relation to the ring burr almost 0.8mm before reaching a similar coffee grinding position compared with the Etzinger burr set. One could say that the Italmill type machining system results in a sort of "mushy" zero while the zero point of the Etzinger system is more strict and accurate. With the Etzinger burrs we can establish a "true zero" point (within about 100nM) and measure all VBM accurately based on threading of the adjustment system components.
There are some tradeoffs with each of these machined burr designs. The Italmill burr set is far easier to "align" in that there is a large area of smooth machined surface. The burrs nest together and as the cone burr moves out of the ring burr any misalignment will not be noticed as it is smooth surfaces touching and not blade to blade contact. Once the cone burr moves the required 0.6mm to reach a true zero (burrs moving but no coffee ground) any alignment defects will not be noticed (no burr rub, which is only noticed when there is a blade rub). This makes the setup of the burr alignment very forgiving as the customer feels very confident with a no burr rub at zero situation = good alignment. Also, there can be grinder to grinder differences of the various settings for grinding, particularly espresso settings, and as the burrs break in the zero points will further change. The Etzinger design has been a hard system to master as the alignment must be very precise right out of the gate and particularly on a new burr set this can be very difficult to achieve. Even though the burrs are made to a specified tolerance of +/- 0.02mm this means that one blade on the + side of this number can feel like misalignment on a new burr and we have to do a lot of special pre assembly techniques to get the desired result....
But here is the point...since we can use an accurate VBM representation of our adjustment settings, we have chosen to lay out the adjustment measuring system in Vertical Burr Movement of the cone burr. A setting of 400nM on the OG stepped ring is exactly that...400nM VBM. This is one of the goals of the OG adjustment system...to use a bona fide measuring system rather than marks or dots or clicks or revolutions etc. We use VBM because it is a REAL NUMBER based on threading and movement of the adjustment discs. Burr Gap is also real but it is a number reached through mathematical calculation of different measured components of the burr face, sometimes based on assumptions. These measurements are difficult to make and can be prone to error or misestimation and burr gap is not linear through the grind range. Particle size at any setting is always a distribution and not a single number.
So to make a long story short, we feel satisfied that quantifying our grind settings using Vertical Burr Movement is both accurate and reflects the real world.
Adjusting the Grind Size
I think we pretty thoroughly explained the manipulation of the grind adjustment system in the basic user manual but here I would like to approach the mechanics and theory behind the design. As an aside, when we introduced the Fixie, which in our opinion has the most simple, straightforward, rudimentary, and basic grind adjustment system, I read a post of the German Coffee Forum, Kaffenetz, that said something to the effect "Orphan Espresso seems famous for making grinders with such COMPLICATED adjustment systems!" So some enlightenment may be in order.
If you check the schematic, the adjustment module is composed of the top cap, the stepped disc, the aluminum platform, and the micro disk, plus associated fittings.
The top cap has a central turret with a 3mm pitch outside thread. The platform has a 3mm pitch inside thread and 3 pins which act as drive pins to move the platform up and down as you turn the stepped disk. If you look at the module with the brass micro disc removed you will see that turning the stepped disc causes the platform to move up and down. When set at 2000 the platform is at its LOWEST point and moves upward as you turn to zero and beyond. The movement from 2000 to 0 is a total of 2mm. When the brass micro disk is installed on the axle and fixed in place with the set screw and associated needle bearing and thrust washers, the movement of the platform translates to the movement of the micro disk which translates to the movement of the cone burr in relation to the ring burr. The brass micro disk acts as a sort of stopping block to determine the length of the axle system.
As per the instructions of setting up the grinder...set the stepped disk at 1 step below zero and hold the burrs together with your finger, then turn down the micro disk until it stops against the platform. We set this up below 0 because at this position the burrs are far too nested and gnashed together to give a "smooth zero". Once you tighten the set screw on the micro disk the burr will move in the described VBM and be accurate through the range.
You may have observed at this point that we have a sort of floating zero, depending on where in the range of the platform you set up the micro disk. This comes in handy in a few important cases....One case is during the break in of the burr set. Grinders are famous for needing to set the adjustment finer as the burrs break in. Since usually you cannot change the 0 point on the grinder the only recourse is to continually adjust finer for the same grind size. With this system you can always compensate by re-zeroing the grinder and are basically always in the same place when it comes to your grind settings. Also, lets say that it just drives you crazy to have ANY burr rub at all at the lowest settings...just set up the zero at the lowest point where there is no burr rub and voila, peace and happiness! BUT the VBM numbers on the top cap will not be as accurate, but the movement of the cone burr in relation the ring burr is the same, only the setting numbers are different for your grind. By the way, burr rub at extremely close settings is a fact of life and easily noticed with a hand grinder...conical burrs are not perfect circles at the interface...close but not perfect and as we live in the real world, its a thing.
Another handy aspect of the floating zero is in the case when you want a coarser grind than is produced at the 2000 mark on the grinder. A 2mm VBM produces a fairly large burr gap, and more people are grinding finer than coarser. We designed the grinder with a stop on the coarse end of the range and not the zero end. So if you want to go up to a 2500nM, when you set up the grinder, just set the stepped disc at 6 marks below zero and turn down the micro disc until it stops against the now .5mm higher platform. This offset will give you a range of 2500 (2000 on the dial is now actually at 2500) -- it will make the numbers less meaningful, but you can't drink numbers after all. Keep in mind that this is a very flexible system and the numbers are not there to drive you crazy.
We mentioned in the basic manual to not overrun the fine adjustment system. This is for a couple of reasons. One is that if you continue to move the micro disk in the coarse direction the brass disk will eventually hit the handle, but overall it is to keep your zero point in more or less the same place and have the VBM numbers maintain some semblance of meaning.....oh yes, I write my espresso setting down on a piece of paper and no, we are not coming up with an APP for keeping track of it.
Taking it Apart and Putting it Together
This part we also cover pretty well in the basic manual. Just don't screw up the brass thread and it's all good.
Alignment of the Grinder
We have put some pretty severe alignment protocols on the build of the grinder and we consider it to be more or less permanently aligned BUT we know that someone will be hell bent to take apart the burr module and need to re align the grinder. The precision machine parts give a good centering of the axle/cone burr and most alignment challenges come from the burrs themselves.
Put simply, with the micro disk removed and the 4 screws of the burr module loosened, turn the body upside down and clack the cone burr into the ring burr. While holding the cone burr in place, finger tighten the screws...just snug them up. Now install the micro disk in the prescribed manner with the stepped disk at minus one as you have done before. Set the stepped disk at 200 and with the grinder upside down slowly turn the axle/cone burr. If you hear any rubbing you need to tighten (little by little) the 4 screws in such a manner as to make any rubbing go away. What you are doing here is tightening the screws in such a way as to assure that the parts all tighten up parallel to each other. First check one screw and observe the effect...better or worse... and proceed until you have tuned out all the rub. I have done this hundreds of times now and it works very well. Make sure the 4 screws are nice and evenly tight when you are done.
That is about it....there are some little things that Barb thought were too basic for the basic manual that I will add here.....we made the hopper plug so it fits really tight in the bean port as not to lose it so, when you install the plug, first put the bottom edge into the hole and then work the top two corners in until the plug is flush all around. We might loosen this up on the next build. Since we were all about precision we made the reference line on the brass micro disc EXACTLY the same thickness as the laser etched line on the F/C range gauge...this turned out to be a little thin, at least for me to see without my glasses...so I marked my line with a black fine marker to see it better. The next run of OG will have a bolder line on the brass. If you bang the stainless jar down on a hard surface to knock the coffee off the burrs you can dent the jar...if you are accustomed to this rough service (I am) use a glass jar (I do, but don't appreciate the lip). If your micro disk setting changes while in use you are not tightening the locking pin enough.
That's about all I can think of. After almost 6 months of daily use my Lido OG has been reliable and trouble free. I have not detected any odd noises or had any need to align or take it all apart (although I have hundreds of times, it was not needed per se). I usually clean it with compressed air once in a while.
Happy Grinding
Doug Garrott