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Thread: How to tell when I need new burrs

  1. #1
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    How to tell when I need new burrs

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Hi all, I have a second-hand rocky/silvia combo and am having trouble getting a decent pour lately. The latest issue is the grinder. I get fresh coffee, like anywhere from 3-7 days from roast, and I cant grind fine enough to get anything more than a 20 second pour, even when overdosing the double basket to around 18g and tamping hard! And 20 is the upper end.

    Ive addressed the basics of fresh beans, tamping pressure and dosage, so Im sure its not that.

    Ive also noticed husks coming in the grind, which looks bad. The grind itself isnt as fine as it used to look, and looks different tamped down. (I can see the tamped dry puck looks more granular than it did six months ago).

    I cleaned rocky out and reset the zero this morning, and its no better. Im pretty sure I set put the burrs in correctly and that its all as it should be.

    Before you say Just set it finer!, I WOULD, except any notches finer than 6 on my particular machine as it currently is (with zero as the definite touching point), and I hear the distinctive chip chip chip of metal on metal. Something that worries me is that its a chip chip chip i.e. pulsing sound, which means something may be uneven. In fact, if I touch the hopper slightly as its making this sound (I have only done this once or twice), the sound goes away.

    Ive had the grinder for 6 months, during which period Ive bought processed maybe 5kg of beans. Before this the previous owner said he made about a double a day for the two years he owned it, which equates to around 15kg of beans, give or take. So It has done 20kg in total.

    Is it time for new burrs from coffeeparts? Or something else?

    Dana


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    Re: How to tell when I need new burrs

    Hi all, I have a second-hand rocky/silvia combo and am having trouble getting a decent pour lately. The latest issue is the grinder. I get fresh coffee, like anywhere from 3-7 days from roast, and I cant grind fine enough to get anything more than a 20 second pour, even when overdosing the double basket to around 18g and tamping hard! And 20 is the upper end.

    You should be able to adjust the grind down to much finer than required, generally indicated by the resulting ground coffee "balling" up ie falling into your coffee filter (if its a doserless model grinder) in sticky balls. The pump cant pump through this once it has been dosed properly and tamped down. So if you cant get grinds this fine maybe someone has had a fiddle with the adjusting mechanism of the grinder and it wont adjust down far enough.

    Ive addressed the basics of fresh beans, tamping pressure and dosage, so Im sure its not that.

    With silvia you need to dose so that the level of tamped grounds is at just the top of the groove that goes around the filter basket about 6 or 7 mm below the rim......otherwise it is not enough

    Ive also noticed husks coming in the grind, which looks bad. The grind itself isnt as fine as it used to look, and looks different tamped down. (I can see the tamped dry puck looks more granular than it did six months ago).

    All of this simply indicates that the grind is too coarse.

    I cleaned rocky out and reset the zero this morning, and its no better. Im pretty sure I set put the burrs in correctly and that its all as it should be.

    See my first note above, you should be able to adjust the grinder down till the resulting grinds are too fine. If not then this is the cause of the problem

    Before you say Just set it finer!, I WOULD, except any notches finer than 6 on my particular machine as it currently is (with zero as the definite touching point), and I hear the distinctive chip chip chip of metal on metal. Something that worries me is that its a chip chip chip i.e. pulsing sound, which means something may be uneven. In fact, if I touch the hopper slightly as its making this sound (I have only done this once or twice), the sound goes away.

    Very hard to comment unless one has the grinder in front of oneself. And you have told us have been in there so I for one cant comment.......can you be sure you reassembled correctly........

    Ive had the grinder for 6 months, during which period Ive bought processed maybe 5kg of beans. Before this the previous owner said he made about a double a day for the two years he owned it, which equates to around 15kg of beans, give or take. So It has done 20kg in total.

    They should be good for about 400 kilos or more depending on the type of blends used.

    Is it time for new burrs from coffeeparts? Or something else?

    Given your descriptions, nothing to do with bluntness / sharpness of grinding plates (burrs), possibly something to do with the assembly of the top plate carrier. Or, if someone has had the grinding plate right off the carrier, make sure there was no grit under the plate when it was screwed back on as this will cause the plate to sit eccentrically instead of true.......

    Also, dont rule out the blend of coffee itself.
    Try a different blend or a compltely differenty source of beans and see what happens, although the most obvious thing that comes to mind given the symptoms you describe, is inability to set correct grind so would be looking there first

    Hope this helps,
    Attilio.

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    Re: How to tell when I need new burrs

    If the grinder is a lot noisier than when you first got it, it could be the blades.

    It should last 400kgs, but if it is not cleaned every night, this can be greatly reduced.

    Also if you have run the grinder while the blades are touching, this also can shorten the blades life.

    You said you can access the blades, so you should be able to feel the sharpness. Also re check the blades are put back in correctly and no spacers have fallen out. (if it has spacers in this machine?)

    Try to dose and tap the same always, then the only other variable will be the grind.

    As the post above notes, you should be able to set the grinder "Too fine" so I suggest tighten it till the blades are touching, loosen it slightly, it should take along time to extract now. Work "slightly" coarser from there.

    If you cant get it fine enough, change the blades and clean your grinder every night!


  4. #4
    Senior Member greenman's Avatar
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    Re: How to tell when I need new burrs

    If there is a bit of play try teflon tape it helps tighten it up. Ive just done the stepless mod on mine and it runs much quieter now.
    There are posts on how to do these mods if you search.

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    Re: How to tell when I need new burrs

    Thanks!!

    Attillio, I took your advice and and a) tried two different blends I bought yesterday from a local roaster, and b) opened up the grinder and painstakingly re-assembled it based on several guides online. I reassembled (double checking a couple of sets of instructions online) and still cant get the grind fine enough without hearing the burrs touching.

    Im going to get some teflon tape to secure the top burr in place, to see if that improves stability and keeps the burrs flat as they move closer, allowing them to get closer.

    I actually see some oscillation in the lower burr that worries me...

    I definitely havent cleaned the grinder every night (i.e., after every coffee), but I will clean more regularly.

  6. #6
    Senior Member GregWormald's Avatar
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    Re: How to tell when I need new burrs

    If the lower burr is actually moving up and down (it may be loose), or installed lop-sided, then something is indeed very wrong.

    I never took my Rocky apart that far so I cant tell what might have happened, but mine would easily grind fine enough that the machine took 30 seconds to push 10 ml of coffee.

    Greg

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    Re: How to tell when I need new burrs

    Dont need no stinking teflon tape hehehe......the equipment should work as manufactured, except where there is the possibility that prying fingers have been in there.......

    dont be fooled with the optical illusion you often get when looking into a grinder and it ***looks*** like the thing is spinning eccentrically. It can just be the optical effect of the central stalk that draws the beans in as it spins around.....

    Sorry but wothout seeing the grinder in the flesh it is really hard to make any further comment.

    Where are you located?

    Attilio.




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    Re: How to tell when I need new burrs

    Im in Vic (St Kilda).

    Im a bit worried something else is wrong.

    Since last post, I bought new blades. I was in the process of replacing them when i realised a bunch of gunk under the blades (between the actual blade and whatever it was screwed to), which I removed. After I did it, on the FINEST setting I was getting great coffee.

    This lasted two weeks, then it was gushing again.

    So yesterday I replaced the blades. I installed them, zeroed the top dial to blades touching point, and I have worked backwards from ~8 notches above zero to ~5 notches - and I still get the same coarse looking grind, and 15 second pours! Even with a heavy tamp!

    Im terrified of going further in case the blades touch and I ruin another pair.

    Also, the old blades dont look too bad. Theyre not shiny - theyre still dull, like sharpened tools look, and I understand this is how sharp blades should look.

    Could something else be causing the slightly granular grind? Im close to taking it to a repairer, which will cost me quite a bit just to diagnose it, I assume.

    D

    PS. I tried plumbing tape with the old burrs but it did nothing, so I removed it :)

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    Re: How to tell when I need new burrs

    It sounds as if there was something stuck under one of the burrs when you re-assembled it. Take them out again and make sure they are SPOTLESSLY clean and there is no possibility of some coffee etc becoming stuck under the burrs. It goes without saying maybe, but make sure the burrs are also properly seated. When you re-tighten the screws do a little at a time ie dont screw one side up tight then go to the next screw or you will warp the burrs. Do one up just a little, then the one opposite it, then the one next, and the one opposite and so on until they are tight. There is no need to go crazy on the tightness either.

    Yes the Rocky needs the teflon tape treatment, and yes they shouldnt but every single one that Ive looked at has had a sloppy burr carrier just as you describe in yours. The tape goes on the THREAD of the burr carrier and just stops it from rocking about like a drunken sailor.

    Pete

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    Re: How to tell when I need new burrs

    I dont know if this is much help, I dont have a Rocky anymore but I found I got quite good results and had no trouble grinding fine enough, as Petef suggests the teflon tape does help. Any way my tip is, when screwing in the upper burr carrier screw it in all the way till the burrs touch and you cant turn the shaft by hand, then unscrew the burr carrier just enough so when you attach the hopper the limit screw is just counter clockwise of where it hits, if you unscrew it to far you could be a quarter turn out when the stop hits.

  11. #11
    Senior Member greenman's Avatar
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    Re: How to tell when I need new burrs

    Ive just replaced the burrs on my Rocky. Ordered them from Coffeeparts and they arrived a couple a days later, top service there!
    Installation went smoothly, I read a few posts from people who had done it and after removing old burrs and giving Rocky a good clean the new burrs installed without a hitch.
    I was amazed at the difference in grind setting with the new set on, I was grinding for espresso at 1-1.5 and now it is around 8-9 mark and seems to grind a little quicker than with old burrs.
    Very smooth changeover. :) ;) :D ;D



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