How to find the grinder true zero point

Grinders are one of the keys to exceptional espresso. Discuss them here.
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#1: Post by jesawdy »

How to find the Rancilio Rocky Grinder Zero point (applicable to many other similar grinders).

You need to start with an empty hopper. So either unplug your machine and scoop or dump the hopper or run the hopper empty before you get started.


Remove the three screws holding in the finger guard and/or hopper. (I am guessing that many folks have removed the finger guard)

The hopper pulls straight up and off when the screws are removed.

You will see the brass upper burr carrier. Unthread it by turning it counter-clockwise until it is removed.

Clean out the grind chamber, upper and lower threads, the burrs themselves and the grinds chute. You can use a group brush, a grinder brush, a toothbrush, a toothpick, a vacuum cleaner, a slightly moist cloth, etc. I've noticed build up on the three brass carrier arms around the lower burr and significant build up on the lower threads in the grinding chamber.

Thread the upper burr carrier back on turning clockwise. I like to turn until it just snugs up onto the lower burr. Verify that it is actually touching the lower burrs by trying to turn the motor spindle; it should not turn (easily at least). If it does turn, you may be hung up on something or just meeting resistance in the threads; tighten it a bit more.

Back off the upper burr just a hair.

Carefully, plug the machine back in and pulse the grinder... turn the upper burr until you get a chirping sound of the flats of the upper and lower burrs touching. This is your zero point or the point at which the grinder will grind the finest.

Unplug the machine and replace the hopper and finger guard. You can orient the grind indicator sticker on the hopper in 120 degree increments, choose the one that puts zero closest to the grind indicator point on the front of the machine. Make a note of what the indicators says that your "true zero" point is.

That's it!
Jeff Sawdy


#2: Post by Canuck »

This is a good instruction, thanks. BTW, has someone ever posted a video of this process including the sound of the chirp?

I've been meaning to remove the top burr for cleaning for some time now, but was worried of damaging the burrs when re-threading/first use. I also don't like the idea of grinding various shots to find the (new) best point for my espresso machine (I would rather be drinking them vs. throwing away sink shots). I know what my settings are now, though I've never cared to find my 0 point, but if I do all of this I'm sure it will be something different). I usually use two types of espresso and one is set on 8, the other on 10...easy to remember. Any way around this...or is it a given that you have to find that point each time?

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jesawdy (original poster)

#3: Post by jesawdy (original poster) »

Canuck wrote:Any way around this...or is it a given that you have to find that point each time?
You only need to know the "true zero" once per burr set. When you replace the burrs (and I think I am about due to) things will likely change. If you remove the burrs (meaning you actually unscrewed the burrs from the individual burr carriers), things might also change, but only slightly.

When you take a grinder apart for cleaning, on reassembly, you just need to be sure that you have threaded the upper burr carrier down far enough. It is possible to hang up on a dirty thread or compacted coffee and think you are there, when in fact you might be one or more full revolutions of the upper burr carrier above the proper location. A quick check for the chirp, and you know you are truly there.
Jeff Sawdy


#4: Post by 'Q' »

If I recall correctly, when I took mine apart, I set the hopper to a number and made note of it. Then, upon removal, marked one screw hole on the burr ring and simply counted the revolutions it took to remove the upper burr and made the same number of revolutions to put it back on (there's a 60 degree margin either way, so pretty easy to get right). Then replaced the hopper aligning the noted number to the mark and the screw holes on the burr ring. Kept the same setting it had before cleaning. Replacing the burrs would most likely change the settings slightly.


#5: Post by Jarno »

Here is a great set of cleaning instructions with pictures:


#6: Post by Canuck »

Thanks to all. During yesterday's cleaning of Rocky I decided to remove the top burr carrier and all worked fine.

One of the screw holes lined up to the arrow on the front panel with the dial set to 15, so I marked this with a sharpie and noted the 15. It took 11 revolutions to remove the burr carrier (I noticed this as well). I didn't think the burrs themselves were too bad, though I had just used Grindz and the vacuum prior to removing the top burr carrier. Once I got in there there was some grinds at the bottom of the lower burr carrier, so I brushed/vacuumed those as best as I could.

In addition to my normal cleaning (everything in the above instructions but I stop at the burr removal...and I do use grindz) I think I'll only do this every 6 months or so.

Couple of related questions:

1) How will I know the burrs need to be replaced (I usually grind say 1-2 pounds per week)?

2) I assume to replace these I unscrew the burrs from the carriers and just replace (and adjust for grinding / 0 point as necessary)?


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#7: Post by HB »

I was searching on another topic and ran across this video Rancilio Rocky Blades Touching? Listening to the soundtrack, it's quite obvious where the zero point is:
Canuck wrote:Couple of related questions:

1) How will I know the burrs need to be replaced (I usually grind say 1-2 pounds per week)?

2) I assume to replace these I unscrew the burrs from the carriers and just replace (and adjust for grinding / 0 point as necessary)?
Almost a year late replying, but...

A1: See the FAQs and Favorites, i.e., How to know Rocky burrs are worn out?

A2: Yes. You may want to do the "thread slop fix" while you're there. It's linked from the FAQs and Favorites too.
Dan Kehn


#8: Post by msaikali »

Zero point in the video - was it the first time you could barely hear the chirp or the second one whereby the chirp was really pronounced - which one is the ZERO point? The first or second???

My Rancilio is not pouring out anything - either too much espresso coffee grains or grain is not at right grind? Any help would be appreciated!


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Randy G.

#9: Post by Randy G. »

Many new users obsess about the zero point of the Rocky... Forget about it. It doesn't matter at all! If nothing is pouring out after the first five seconds or so after you hit the brew switch, you are grinding too fine. Either that or the reservoir is empty. If there is water in the reservoir, set Rocky one or maybe two clicks more coarse (larger number) and try again.

If you go to my website, besides finding a week's worth of reading, be sure to read the "How To" #12 in the right-hand column. It will contain a lot of useful information that will help you get more out of your espresso machine.
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