Stepped adjustments too large on my grinder but not on others..

Simon

Hey guys, thought I'd post a thread about this and ask for your much much appreciated knowledge and advice.

Having spent a month and a half with my grinder, it just really seems that the stepped adjustments are too large. I've even gone to the extent of doing a few shots on a setting, removing the top burr and doing a full cleanout of it, toothbrush, brush, vacuum etc, purging, then pulling few shots on a new grind setting, yet it's very very clearly showing me that the steps result in such a dramatically different yield (20+ second difference for one notch change...)

I've actually gone around and asked many people who have the exact same grinder how they found the steps, and all except one person have said that the steps are really small and haven't been an issue for them.

Can I ask for some collective wisdom as to why this might be? That the same grinder can vary so much? I did get it secondhand, but it had only done about 12 kg or so and looked in great condition apart from some dents on the inside (which I have attached here just in case this might be part of the issue). The burrs look fine although I have no idea what they really should look like, but photos below. Do the burrs look okay?

What would you guys say is the best course of action here? Get new burrs just to see if that's it, deal with it and live with it, or side/upgrade to another grinder?

It's a Quamar Q50P, otherwise a really great, solid grinder that's awesome in every other way.

Thanks so much for any thoughts guys

Photos are of before cleaning, after cleaning (actually scrubbed it more after those photos), and photos of the dents

Brett H

Sorry mate... I can't speculate despite the great pictures. Having owned a Rocky the steps aren't an issue that is insumountable.  I wonder if you've not got a grinder that caught a stone or some-such. Also may be worth checking the shaft is straight. I had a used grinder early-on with a bent drive shaft and I ended up ditching it!

Koffee_Kosmo

The step adjustment on a coffee grinder is closely linked to how fine the thread is on the burr carrier A finer thread gives you small adjustments Most grinder issues can be summed up with the list below Humidity Heat Beans left in the hopper Age of beans - they can change daily Intervention by God  :angel: KK

mycuppa

Sorry Simon, I also can't help you mate. Never used one of those, so I would not offer a comment. Personally, I don't like stepped grinders for the simple reasons you are faced with currently, however, as KK mentioned, it comes down to the design - not all grinders are created equal. Up to 20+ seconds difference per step is a big concern IMO - assuming of course you are using well developed coffee beans and they have degassed. The score marks internally are bizarre. Like someone's used the end of a screwdriver to force something. Those are not from stone damage and your burrs look fine. Even the odd minor chip on the burrs won't cause that great a variance. I guess you could start by using a process of elimination - get 2x grinders side by side with the same coffee and dosing techniques. They don't have to be identical model grinders, just so you can eliminate something as simple as technique. The other thing I will share with you Simon is that as Brett eluded - there are lemons out there. I'm not suggesting for one moment you got a dud, but let me tell you I've owned my fair share of lemon Compak's and Mazzers over the last decade. They appeared perfect in every regard, but in service duty they would throw wobblies. We live in a modern age of manufacturing, but stuff goes wrong in batches. You may discover that some owners of the same grinder you have are not as precise (or fussy). Eliminate as many external variables as possible, then when all else fails, Xmas is fast approaching - you deserve a new toy.

K_Bean_Coffee

Hi Simon. I know you are having a tough time here but you really need to go back to technique. I have sold more than 100 Quamar Q50Ps and believe me you are the only person who has reported any issue with the steps and I haven't had a single return (and yep, I have a 30 day returns policy) I also use this grinder every day at home and for all demos and for training. Head back to the 20 steps here Simon: K Bean - 20 Steps to Great Espresso Keep plugging away and work on your workflow. Cheers from Paul Sent from my iPhone using Tapatalk Pro

K_Bean_Coffee

.....and drop in for free training any time Simon Sent from my iPhone using Tapatalk Pro

Simon

Thanks so much everyone for your very generous replies, I truly appreciate it. @Brett H, yeah I might even just take out the lower burr, not sure what/where the shaft part is exactly, but maybe I'll find something really obvious like a bird has flown and gotten stuck in there, or a giant red button saying 'Equalise Steps' haha.. @KK ah interesting about the threads, makes sense, they look pretty fine but not sure. And doesn't seem to be an external factor (well, not one that I can spot).. @mycuppa, definitely am using well developed and rested beans (Honduras beans from a certain someone named Jeff... ) Hmm I still have my Rocky grinder I could use side by side... but that's the thing, I really can't see it as being technique that's the issue (and I'd definitely be the first to admit and be honest if I'm struggling somewhere!), because I can get very consistent extractions on the same grind setting, yields/times are +/-1 or 2 grams. Just when I change setting it goes to extremes. And may be a wobbly, but don't know how I can figure that out... @K_Bean_Coffee, thanks heaps for the offer appreciate it mate. Like I posted earlier, I'm getting great consistency on the one setting, so that makes me think it's not a technique/workflow issue, I am a stickler for keeping things repeatable and to the 1/1000000th degree accurate haha... but I'm more than willing to honestly look at my technique again and treat it still as a possible factor. And there was the fellow from the other forum who did have issues with the steps, but yeah I've asked around and no one else seems to have issues. Okay, current plan of action: -take out bottom burr, clean out, see if any tree branches are stuck in there -Keep all variables the same when pulling shots Thanks guys, any more thoughts feel free! Edit: or perhaps just more kgs of beans need to go through it to 'season' it?

Brett H

Hey Simon, I know folks wax lyrical about seasoning burrs but I reckon it's the users who become seasoned. Did you buy this brand new or is it second hand with new burrs?

Brett H

Looks like the carrier for the bottom burr set sits directly on the motor. Look for anything out of plumb there. Also, while it's disassembled wind the top burr carrier until amost touching then manually rotate the bottom burr to check burrs are parallel. If you get a grab-release effect the burrs aren't level with each other.  KK may know how to better explain with tech-talk.

Koffee_Kosmo

You can check for spinning accuracy by placing a dot on the lower burr shaft Turn on and observe If it's an even and continuing Circle then it's most probably OK If the visual result is oblong with wobbling then it's out of centre Just remember any adjustment you make to the grinder will always produce a different result in volume I never let the grinder have that control It's best to grind as much coffee as required to the physical part of the equation   You tamp to the correct compaction & level required for best repeat results by your machine That level is normally just short of the puck touching the water dispersion screen when fully locked - no matter what filter basket size you use And adjust your compaction of the grinds as needed KK

Simon

on 1505698753:

Hey Simon, I know folks wax lyrical about seasoning burrs but I reckon it's the users who become seasoned. Did you buy this brand new or is it second hand with new burrs?

Yeah it never made sense to me that burrs needed seasoning.. not sure what that really means, I wouldn't think the sharp bits would change much in shape or mould around the beans or something over time hehe, but I plead ignorance here so not sure. I bought it secondhand (I'm assuming with the original burrs), but it had only done roughly 12kg or so, the fellow had it for a year. Seems like it's in great condition apart from them dents in there.. I'm wondering if that could affect the grind, as some of those dents are right on the threads... :S

on 1505699264:

Looks like the carrier for the bottom burr set sits directly on the motor. Look for anything out of plumb there. Also, while it's disassembled wind the top burr carrier until amost touching then manually rotate the bottom burr to check burrs are parallel. If you get a grab-release effect the burrs aren't level with each other.  KK may know how to better explain with tech-talk.

Ah ok, yeah not 100% sure what you meant by that hehe.. as in when I've taken out the bottom burrs, or while they're still in? I think i get it, while the top burrs are out, wind them in, reach just before zero point, then manually rotate the bottom burrs to see if they catch and let go? I also tried removing the bottom burrs this morning, and golly gosh they are screwed in tight haha, could only loosen one of the screws, will give it a bit more oomph tomorrow.

on 1505700613:

You can check for spinning accuracy by placing a dot on the lower burr shaft Turn on and observe If it's an even and continuing Circle then it's most probably OK If the visual result is oblong with wobbling then it's out of centre Just remember any adjustment you make to the grinder will always produce a different result in volume I never let the grinder have that control It's best to grind as much coffee as required to the physical part of the equation   You tamp to the correct compaction & level required for best repeat results by your machine That level is normally just short of the puck touching the water dispersion screen when fully locked - no matter what filter basket size you use And adjust your compaction of the grinds as needed KK

Ah right, thanks KK might try that, assuming I can get this bottom burr out haha. One thing I have noticed is that even when on a particular grind setting and it's locked in with the spring button, the collar still moves around a little freely.. surely that's not normal? While grinding it looks as though it doesn't move around, but if it's slightly out of place, as soon as I run the grinder with beans in it, it moves and snaps back in place against the latch/button... I'll actually post a vid of what I mean soon haha. Thank you thank you thank you guys, appreciate the help, will keep posted how it goes..

Koffee_Kosmo

If the collar moves when beans are grinding that is kinda normal for this to happen as it's inertia To stop it happening you need to check your spring lock clip as that is the component that stops the inertia from moving the burr carrier Try to move the collar back and forth by hand until it's locked in before grinding Check the spring clip to see if it's OK or broken If broken you should replace the spring clip with a unit that does the job as it was designed to do KK

Simon

Ah right... yeah you'd think the spring clip would hold it in place to keep it stable while grinding... The clip is a little flimsy and moves around a bit.. not sure what it's supposed to be like.. I'm always purging first anyway so that locks it into place to begin with, I'll show the spring clip in the vid anyways. It doesn't look broken as such, just not really that stable, unless something is missing from that area..

Koffee_Kosmo

I have a stepped grinder and the spring lock clip is sturdy My unit also has a ball bearing under the spring In any case you can use " not teflon tape " some plumbers hemp thread tape to help any movement as a test I will link the closest PDF schematic of your grinder The part is number 8 & 9 http://www.espressoconnect.com.au/servicing/quamar/Q50S parts diagram.pdf KK

Simon

Ah thanks for that, yeah part 8 and 9 is there (which I'm assuming part 9 is the spring). Cheers for that, and yeah someone suggested using teflon tape (but a fair few layers of it to keep it from moving) so I may try that. I'm also wondering if all those dents have anything to do with it.. Like when I change to a new grind setting perhaps it slots into those dents as they're right on the threads and causes a funky result.. but who knows

Koffee_Kosmo

No those dents are not in the thread area and even if one thread has a dent the other threads would take up any slack The dents would not be the cause And they actually look like pitting or a manufacturer fault Also be aware that teflon tape is not easy to remove after it's on and will not last long with back and forth movements That's why I suggested the hemp KK 

Simon

Ah right that's good to know they're not an issue. Ah I see, yeah the teflon can rip apart quite easily I guess.. I'll look into that, cheers mate

Simon

Okay a little update... I took apart the grinder a little, took out the upper burr carrier, then the upper burr (inspected, looks fine, very sharp, cleaned it a little), managed to get out the bottom burr (same deal), looked around under there, all looks fine and I can't spot anything amiss.. I tried to get that central nut out but with all my might could not haha.. don't really have that many tools around, tried an adjustable wrench but it was just too tight. But anyway I reinstalled the lower burr, upper burr, and everything. I did however notice that the spring clip you push down to adjust the grind setting is quite loose in there, I actually think it's a matter of that the hole diameter is just too big, so it slots in there but can move around left to right a bit, which obviously affects the upper burr carrier and the stability of the setting that it's on. I shot some photos and did some videos too! Apologies for the repetitive nature of the videos, but just thought I'd cover all bases. You can see the springed clip and how it moves with the upper burr carrier quite easily, and also in the clip where I grind some beans how it does that 'snap back' I mentioned earlier. Not sure if this is potentially the issue... doesn't seem that it would affect the dramatic difference in steps, as even when going between steps they seem quite small in the threads in terms of how much it's adjusted.. so whether this little movement is causing too many inconsistent grinds or it's just not stable to even know what setting it's on I'm not sure... I even tried to wrap some things around the spring clip and put it back in to try and stabilise it (wrapped paper around it, blutac etc) but couldn't slot it in. So whether this itself needs addressing or wrapping tape around the threads not sure. May have same effect. So the photos are of the area where the lower burrs were removed from, and the burrs themselves. One strange thing though, the shot I pulled this morning (before the big stripping apart) was 20.5g in on grind setting 1.4, yielded 27.6g in 35s. Then this afternoon I did the cleaning and reinstalling, and went one notch coarser as the shot was a little slow. Purged a decent amount, about 10 grams (even though I'd cleaned and vacuumed everything out). Same dose on grind setting 1.5 (one notch coarser) yielded 19g in 35s! Bizarre, perhaps I've reset something in there! For tomorrow's shot I'm gonna go a touch coarser and fingers crossed something has been fixed here...

Simon

Vids

Koffee_Kosmo

Seen the video That lock mechanism does not look like it's doing its job Question - Is it all plastic ? I will post photos of my all steel lock mechanism to compare

Simon

Ah right, yeah the actual removable black clip is plastic, but the 'teeth' that it locks into on the collar seems metal... although I just tried to snap a magnet onto it and it didn't take (not all metals will I don't think..), so not really sure what material the collar is, but the springed clip is definitely plastic. Just another thing, I think I've altered the zero point, that's why the shot i pulled was so slow. Turned the grinder on and went finer and the zero point (the audible noise where the burrs 'kiss') occurs much earlier.. not sure how I altered that haha

Koffee_Kosmo

My top burr carrier is brass with a very fine thread I suggest that you ask another owner if they have that issue And if so purchase a new locking clip Its possible that the manufacture may have updated to one made in steel on a newer year model ? KK

Simon

Yeah that's an idea.. the slots on the plastic clip do fit really snugly into the carrier teeth though, but it's just the way it fits into the hole that I reckon is the issue.. Just sits too loosely in there, the hole being bigger than the insert..

Koffee_Kosmo

Wrap some aluminium foil around the shaft to take up the slack and give that a go KK

Brett H

Terrific troubleshooting KK.  Thank you!

Koffee_Kosmo

on 1505810026:

Yeah that's an idea.. the slots on the plastic clip do fit really snugly into the carrier teeth though, but it's just the way it fits into the hole that I reckon is the issue.. Just sits too loosely in there, the hole being bigger than the insert..

I had a closer look at this / your photo (below) see area on left hand side the hole And would like another photo from above please so I can see it better without the clip It's possible that a removable/ replaceable collar is fitted in the top of the recess to stop the movement and it's gone missing KK

Koffee_Kosmo

This is a photo of brass "shaft guide collar" that I found on the internet so you get the idea of what I am trying to convey

Simon

Ah wow, that is a very real possibility haha... yeah as far as I know it came like that, there is just the hole, adjustment button, and the spring that sits inside the hole. It would make sense that one would be there to guide the shaft and hold it still.. pics below. Ps. I really really appreciate all your help with all this KK, I'm at a loss with all this, and close to just getting a new grinder, but if I can salvage it that'd be great as I do love the grinder otherwise

Koffee_Kosmo

I am a mechanical engineer so I look at things logically You see on the last photo - there is a larger recess hole (top) for a few millimetres to that of the lower section hole where the spring is If your lock pin is swimming in that larger top section but snug in the lower section - then we may have found your issue You probably need a guide collar Contact Paul to see if a new unit has a collar or similar guide insert that slips in from top all the way to the bottom to confirm KK

Simon

Thanks KK, yeah I even looked it up on the Quamar website and the schematic only shows the pin and the spring, so not sure if there are any newer models, and also the Bombora one they have all sorts of spare parts and they only sell those too, no guiding collar (they didn't have the Q50 on there, but had a few other Quamar and Fiorenzato grinders that had just the button and spring only). I even rummaged through the old box for the Quamar and couldn't find any missing pieces hehe.. I wonder if there's anything similar I can buy at the hardware store, otherwise I'm just leaning towards a new grinder... and selling this one to the lucky person who wants it :D ;D. That's the thing, if it's really only just my grinder doing and not many others, then it doesn't make sense, if it generally didn't come with a guiding collar everyone's grinder would be having the same issues.. anyways I shall ask and see.. Thanks mate Will also try wrapping foil around the shaft, the paper i tried just screwed up ripped when I tried putting it back in the hole haha..

Koffee_Kosmo

Based on all the supplied information of the fault I am confident that we have found your issue You have a couple of options 1) Add a thin metal tube sleeve over the plastic shaft - this will take up the slack & make it tight in the hole and will take the daily use operation 2) Add a collar on the top KK