Every morning since April 2018, I would grind one scoop of beans at the largest setting, 8, for my French Press cup of mocha. It was quick, it was easy, in about 25 to 30 revolutions of the handle I had my coffee grounds ready to go. Cleaning was fairly easy but the bean oils were difficult to remove inside the top hopper.A while ago, I’m not certain as to when this began, I felt a grinding sensation rotating the hand crank when I was done grinding the beans and there were no beans left to grind. I didn’t pay any attention to it. If I had known this symptom was the precursor to failure I would have stopped and solve the problem. Hint! Hint!If you are using a Handground Precision Manual Coffee Grinder, heed my warning: if you rotate the handle with no beans in the hopper and you’re feeling and hearing a rhythmic thumping, grinding sensation and sound, the internal gears are out of synchronization. The gears are not meshing the way they did originally because the gear set screws are loose. Do not rotate the crank anymore. The top cap assembly needs replacement. If your Handground Precision Manual Coffee Grinder is still under warranty, send it in for repair/replacement.Otherwise, you will have to disassemble the top cap assembly.WARNING THIS IS NOT TO BE ATTEMPTED IF YOU ARE THE LEAST BIT SENSITIVE TO THE SIGHT OF BLOOD OR INTERNAL WORKING MECHANISM! Or if you lack mechanical aptitude, the tools or the time.This will take some specialized tools, Phillips head screw driver of a particularly small size and a 1 mm Allen wrench, hex head wrench. Be aware that there may be spacing washers or shims on the shafts of all these drive gears. If they are present, they will need to be returned to the same position. The three screws holding the top cap together are Phillips head, use a precise sized Phillips driver or you will round off the Phillips screws and then you have a paperweight. Carefully remove the screws and place them in a secure container, my preference is a Titan Tools 11061 Mini Magnetic Parts Tray.After you have disassembled the top cap assembly, you will see six more Phillips head screws securing the cover plate of the gearbox. Carefully remove those six screws, they’re small, put them in the same secure container. In figure one you will see the exposed gears under the cover. In this same image you’ll also see the set screw securing the gear to the drive shaft. The sets crew is the problem, it has become loose. The set screw is a 2.5 mm screw and I think it will require a 1 mm hex drive Allen tool to remove it. Do so very carefully this is an extremely small screw. Place the screw in the secured container. You can now pull the crank shaft out and remove the gear. Now the vertical driveshaft is exposed and can be removed. Remove that set screw as well, I don’t need to tell you what to do with that set screw, right?Figure three is the underside of the gearbox cover, and you can see a lot of debris and pieces of metal. Clean out the interior of the gearbox carefully, you want it absolutely clean.The two gears appear to be interchangeable, however, if they are not you must return them to the same original position in the gearbox. Take whatever steps are necessary to ensure this happens. Use a magnifying glass to closely evaluate the gears if they appeared undamaged they can be used again.You will want to have some thread locking fluid before you reinstall the set screws. Using an appropriate solvent, follow the cleaning instructions accompanying the thread locking fluid.Clean the gears very thoroughly removing any oils and debris. Be sure to clean the inside of the threads for the set screws as well as the set screws, according to the instructions for the thread locking fluid. Allow the cleaning solvent to dry thoroughly.Now you’re ready to reassemble. Being mindful to return any spacer washers to the original position, place the gear on the vertical shaft aligning the hole for the set screw with the flat surface on the shaft, following the instructions of the thread locking fluid apply the fluid, it will take very little on a screw this size. I put the fluid on a toothpick and then applied a very small amount on the screw threads while the set screw was on the Allen wrench. Insert the set screw back into the hole and tighten down snugly. Wipe off any excess thread Locking fluid. Replace the vertical drive shaft with secured gear, into the hole of the top cap, checking to be sure it rotates freely. Slide the hand crankshaft into the top cap aligning the appropriate gear (and any washer spacers) with the shaft as you insert the shaft into the gear. Align the screw whole with a flat surface on the shaft. Repeat the procedure for the previous screw. Using the toothpick technique, place a small amount of light silicone oil on the gears. (WD-40 is a Water Dispersant, not a lubricating oil. That is what WD stands for) Replace the gearbox cover, screw in place, do not over tighten the screws, it is easy to do. Somebody told me that. Reassemble the head and you’re back in business.In my effort to accomplish what you have just done, I discovered the gears had been severely damaged. They would still work but for how long, I do not know. My caution about having a magnetic storage place for your screws is the result of losing one of the set screws. They both fell from the table onto the floor. Amazingly I found one but the other did not reappear. That’s how I found out what size they are when I bought a new one cost: 30¢ I have been able to reassemble the drive, and it does work but it still has that vibration feeling and sound I described originally. No idea how much longer this will last but that’s OK, I purchased a replacement thinking my Handground Precision Manual Coffee Grinder was done for. I’ll do a review on the new one after I’m done with this review.And another revision, September 13, 2019.I currently have four Handground units - three defective with jammed shafts as described in my earlier review (below) and an original Kickstarter unit that still works.I just took apart all three defectives and found the shafts scored where they enter the bearing at the base of the hopper. Contaminants in the beans (probably dirt) get caught between the shaft and the bearing, scoring the shaft and causing it to bind.A possible fix is to put an o-ring or piece of tubing on the shaft and press it against the bearing. This will keep some contaminants out provided the grind setting isn't changed. A more permanent fix would be to put a shaft seal on the bearing holder or, better yet, go back to the sintered bronze bearings used in the Kickstarter units - not sure Handground is going to do either.The Kickstarter unit uses sintered bronze bearings while the newer units use stainless steel bearings. A competent machine designer would veto the stainless shaft/stainless sleeve bearing combination since stainless binds easily to stainless in moving assemblies. Clearly whoever did the cheapening redesign was ignorant of this.April 2019: This is a revision of my previous 5-star review. Would be a zero star but that's not an option.I purchased another Handground in April 2019. I used it at our weekend place while continuing to use my original (Kickstarter) unit at home. The new Handground failed in less than a month: the vertical axle seized up. I got a replacement from Amazon (it was still in the 30 day replacement period). That one failed in the same way after three months of use. Two identical failures in three months? Hmm...after a bit of study I believe the root cause is a change made in the lower bearing mechanism sometime after the original Kickstarter units were produced.See photos:Left (black) unit was purchased on the original Handground Kickstarter campaign (2016) and has been in near daily use for well over two years. Note the bronze bearing around the center shaft.Right (white) unit was received in April 2019. Note the plastic surrounding the center shaft - the bronze bearing found in the original has been deleted and replaced with plastic.The white unit and its immediate predecessor failed in the same way - the center shaft seized up while grinding. The unit got harder and harder to turn before this happened; as this was going on I noticed the gears in the top were sounding a bit distressed - I'm guessing these would have failed if the shaft hadn't seized first. Quite a few other reviewers mention failed gears.OK - what happened? Someone - either a Handground designer or a contract manufacturer substituted an inferior bearing for the original. As a result an excellent product has become useless.To add insult to injury, Handgroud support seems overwhelmed and unaware of their own warranty terms (that's a charitable way of putting it).When the first unit failed we exchanged it on Amazon for a new one as we were in the 30 day exchange period.When the replacement unit failed well after the 30 day exchange period we contacted Handground support and asked for the unit to be repaired and, after some fiddling, Handground said they sent us a 'repair kit.' Three weeks later there is no sign of it.So today we asked for a refund - and were refused. This is contrary to their warranty terms. When we pointed that out they asked for return of the product - at out cost - and said they will give us an Amazon credit when it shows up at their Texas facility. We shall see - needless to say the return unit is going via a traceable carrier.This is a good example of how to ruin a product franchise: cheapen it and don't support it.Conclusion: DO NOT BUY THIS PRODUCT.And here's my original review:I first used a hand operated coffee grinder over 40 years ago. It was wall mounted and used steel/iron burrs. At the time (mid 1970s) they were common junk shop items, having been made by several Wisconsin companies well into the 1950s. For various reasons, including bits of metal in the grounds, I switched to an electric grinder and gave the hand unit back to my sister-in-law.When I switched to Danish press (aka 'French' press - marketing at work...) brewing about five years ago the electric grinders weren't up to the job. I went through four or five electric models w/o much joy and had to settle for store-ground coffee. The problem with home electric burr grinders (and don't get me started on blade grinders - ugh!) is that the burrs are too small and spin too fast to get a narrow range of particle sizes. That is, a coarse grind results in maybe 50% of particles in the correct size range but the rest are undersized with many fines (1/10th or less of the desired size). This clogs a Danish press and gives muddy coffee - good for those who like Heretical roasts ('burned at the stake') but not for me. Large commercial grinders found in stores use much larger burrs that spin relatively slower giving a narrower size range and better brewing results.So I went back to a hand grinder - only to find my cast iron fav of the 1970s had become a trendoid artifact with worn out units going for $100 or more in 'vintage' (otherwise known as 'junk') shops. Ugh.I tried several vertical axis hand grinders and found them a PITA to use - the ergonomics of operating the units are not consistent with the strength of the human wrist - the wrist is weak in the plane in which the turning force is applied so the grinding action proceeds in fits and starts. Not for me.When Handground launched a Kickstarter campaign to make a horizontal axis grinder I jumped on board. My first unit was very good and improved greatly with the new burr supplied about six months after launch.Now I have a second Handground - works great, makes good ground coffee in good time - ~1 minute to grind 2 ounces of beans for my Danish-American press (Espro).So, get a Handground and toss out your vertical axis hand grinder. Your wrist and arm will be much happier - and you will drink better coffee!I've been using it for 2 days now. Lot of experiments with espresso. The wheel is a good guide, refer to it and adjust to your taste. Equipment used:1. Delonghi Dedica EC685R2. .Bottomless portafilter3. Standard portafilter.4. Coffee from CafeDirect.5. Temperature medium.6. Water, bottled still water.7. Scale, blackmirror scale.For espresso, I found out that turning the grinder scale to 1.5 works best for me. 1 is best for Arabic coffee, very fine. the grind was consistent across many trials. With the right tampering pressure (trial and error) it gives a lovely espresso.Easy to hold. The top cover turn right to open. This is because (I think) when holding it with your left arm and grinding, your left arm tend to pull to the left so you cannot open it accidently as opposed if it open to the left (left arm on the top cover). My son is left handed and had no problem using it.The bottom glass container is good and sturdy but i wish it was stronger as it feels it may fall of but it never did (I had the plastic grinder).Capacity 100g more than enough for 2 people. 5.5 double shots for 18g portafilter and 7.14 double shots for standard 14g portafilter.Quicker to grind than my basic manual grinder.Easy to take apart, store, clean etc and compact enough to transport.You have to experiment with tampering and roast to get the perfect shot (expect to waste a lot of coffee tasting and experimenting - not unique, this is also true of electric ones as well).Overall I am very pleased with it and it does the job until I can afford an electric one which can grind consistently for espresso.Recommended.I very much liked the coffee it ground.I did not (even try to) change the supplied additional washer shims.While this grinder actually worked properly I did enjoy what it made.Less than a year later this is no longer so.The grinder has been used twice a day grinding beans for two people.I disliked the build quality:* Whole handle fell off :: retaining screw needs an unusual tool.* Winder mechanism now 'binds' at about the 12 o'clock position.* Something is now rattling in the header unit (winder mechanism).* Specialist tool needed to access header unit (so I can't fix anything).* The flat perimeter ledge at the bottom of the hopper ALWAYS catches a bean or two (why wasn't it sloped inwards so the beans naturally fall into the burr jaws!? DUH).* I disliked the counter-intuitive clockwise undo of the header unit.* Protective mat (for the sticky bottom pad) 'crazy paved' and then fell apart while being removed from the sticky pad. This has effectively rendered the sticky pad largely useless - due to dust fouling.* With a now useless sticky pad AND a binding winder mechanism the grind process is not a particularly easy or pleasant activity, though it is still possible. For how long this will continue may be moot noting this recent rattling noise (loose screw?) in the header winder unit.This purchase, not even a year old, has already fallen out the 'return goods' facility on my Amazon page and so, I presume, I cannot even return it. Zero marks for lasting less than a year with very light use and no apparent 'one year warranty'.Apparently the grinder was designed by coffee lovers for coffee lovers, from my point of view perhaps it should've also been engineered by engineers.I am unwilling to recommend this grinder on the basis of what I was supplied and its short life - less than a year.A more competent electric burr coffee bean grinder is now being purchased.I bought this grinder because it has ceramic burrs, the inner one being conical so that beans are channelled down to the grinding surfaces, It is very well made and works excellently, The only problem I found was that the instructions for dismantling the burrs for cleaning given in the leaflet is for the old version which had a thumb-nut to secure the burrs to the axle, but from November 2017 this nut was changed to a plastic insert that is flush with the bottom of the conical inner burr so that it cannot be grasped with the finger. The reason for the change is that when beans have been ground and the chamber with the ground coffee is removed, the projecting thumb nut stopped the bean chamber from being stood down upright, but the new system cures that. But to clean the burrs in the new system one has to go to the Handground website to find out how to remove the burrs and the method shown in the video isn't too easy to use as the plastic insert on my grinder had been screwed in very tightly. Resting the grinder upside down on my leg and holding my hand flat over the burr assembly when turning the handle counter-clockwise as shown in the video didn't unlock the plastic insert, but when I placed the grinder upside down on a carpeted step of my staircase rather than my leg, I could put more pressure on my hand over the burr assembly and managed to unlock the plastic insert. I haven't done it up as tightly on reassembling the burrs as had been done by the factory, and it is now a lot easier to dismantle the burrs for cleaning.I used this for around a year and it was able to produce a decent grind. I found that a setting of 1.5-5 worked well in my Gaggia Baby machine. The gearing in the head allowed fast grinding compared to other hand grinders.However, it was that gearing that was its downfall. After a while, the handle started binding and eventually, the handle started crunching as the gears failed to engage. I opened the top up and found that the construction was pretty poor, with only the moulded plastic holding the two shafts with the mitre gears in place. As this plastic eventually wore away, the gears were unable to mesh and no amount of adjustment could compensate for the wear. I feel that maybe if they used some metal bushings/bearings between that plastic and the shafts it would have lasted a lot longer.It's interesting they supplied a shim to compensate for the burr wear when clearly it's not the burrs that will fail first in this product.This is, when it works, a great coffee grinder. Simple to use and grinds great coffee. BUT... this is now the second time its broken in a year. It keeps breaking at the 6 month mark oddly. I grind between 2-4 double espresso's worth every day pretty consistently and both times its broken at the crank area, as though it gives up after a while.A £70+ piece of equipment I kind of expect to last longer than 6 months. On the upside the company were helpful in shipping me a replacement part (even if it did take almost 2 months to get to me in the UK). It's just broken this morning for the second time so lets see how helpful they are this time!If it hadn't broken twice i'd give it 5 stars but as it has broken twice it's only getting 2 stars.