Rocky Mods - How to turn it into an uber grinder

Grinders are one of the keys to exceptional espresso. Discuss them here.

#1: Post by snoboy »

The craze seems to be modding your espresso machine to stabilize the temp and pressure, or to be able to see the beautiful streams of brown elixir...

I focused more on grinder mods at first, since the grinder is the most important part of the equation.

There are three things I have done, two of them are original, and one of them is not.

Continuous grind mod

The first and easiest, rewiring the switches for continuous grind on a Rocky SD.

Easy access chute

This one requires some metal working skillz, but it really makes life easier. It even looks like it could be stock, hint to Rancilio...

I hope this pic is self explanatory. If I can figure out how to export an image file from my CAD, I will post that up too eventually.

note: click on photos to link to larger, annotated pics on


Infinite grind adjustment mod

This is probably a med difficulty level trick, it does require one special tool, but the parts are all easily available. I wanted to play with the big boy grinders - I wanted infinitely adjustable grind adjustment!

So, I did it, it needs some refinement, but it works, and it is cheap.


The key was the worm gear part of the drive, which started life as a 6" lag bolt. I cut the head off, and threaded the shank at the top with a 1/4"-20 die (the special tool) to make a long hanger bolt.


Another view:


Hanger bolts are available, but I have never seen one as long as needed.

The second modified part is the coupling nut that makes a bushing at the left end. I drilled it out about 2/3 of the way with a 1/4" bit to remove the threads.


Another view:


Everything else is stock parts off the shelf, here is the shopping list:

1 X large hose clamp backed by thin cardboard to protect the hopper
2 X 90 mending plate
2 X flat mending plate
1 X 1/4-20" coupling nut
1 X 1/4-20"x1/2" bolt
1 X 1/4x6" lag bolt
2 X 1/4"-20 nylock nuts
1 X 1/4"-20 wing nut
4 X medium "3M Command Adhesive strips"
1 X wooden wedge to block the factory adjustment button open.

It takes about 2-1/2 turns of the screw to go one notch on the Rocky. Assuming that it is easy to judge an 1/8 turn, I have increased the resolution of the grinder by 20 times. There is a thought that a notch on the Rocky ~ 10s change in shot time... so now I can dial it to ~.5s...

I am really happy with all these mods. I think it has tuned Rocky into a very capable, easier to use grinder. The only thing I would change, is that I think it would be nice to be able to go back to the click adjustment for grinding presspot coffee, or cupping use. I don't think it would be too difficult to make brackets that could easily pivot the lag/hanger bolt out of the way to allow this, although it would probably necessitate drilling the case to attach.


#2: Post by kdkrone »

I admire the design for the chute. Would you consider fashioning one for a price or providing a template that I could play with? (I promise to respect your intellectual property rights!)

I have bent a wire brush that I can sneak up the original plastic chute, but I would probably use it more often if I could lift the cover that you have made.

Clever ideas...

Ken K

User avatar

#3: Post by malachi »

Excellent idea with the worm drive adjustment. Probably the single best improvement you could make to a Rocky. Well done.
What's in the cup is what matters.

snoboy (original poster)

#4: Post by snoboy (original poster) »

A little followup:

I never got around to making the worm drive mod more permanent. Just last week the adhesive strips started to fail. I found it fairly trivial to replace them, and actually got a better fit this time around. The screw was always a bit crooked, and I took the opportunity to straighten it out as well.

I don't think I could ever go back to a stepped adjustment, at least not one as course as the Rocky. The last week without the worm drive was challenging indeed. Trying to adjust pour times by up and down dosing... ughh!


#5: Post by jonbauer »

This is not a commercial post. I do not benefit in any way... Just trying to share some good news...

Wanted you let you all know that I found a Click Clack (0.7L size, model 2010) at my local Bed Bath and Beyond.

They are also now stocking the Bodum Yohki jars with SS lid.

Both of these were NOT at my BB&B a week ago!

I also posted this info here: ... 235#271235 Lot's of info about Click Clack there too... The Click Clack is a kind of "hack" for flushing out the old grinds in a Rancilio Rocky.

Hope this helps someone.

- Jon

User avatar

#6: Post by HB »

Nice find Jon, I've merged your topic with snoboy's "uber mods" for Rocky. To add context, I've excerpted part of the first post in Flushing Rocky (Part II) on CoffeeGeek to explain:
CoffeeMe wrote:...After reading caffeguy's great post on plunger/piston arrangement to "flush" his Rocky, I started to put together parts to do his mod. While roasting one day, I suddenly realized that maybe my new airtight bean container's lid might fit. Wow, it fits perfectly on the hopper. One would have thought it came standard on a Rocky!

Squeeze the toggle lid (see photo below - green toggle on top of lid) of Click Clack, thus loosen the fit slightly inside Rocky's hopper. Just pump the lid a few times up/down in the hopper, all left over grinds will flow out of the chute :-)

No mess and no modification needed.
Dan Kehn


#7: Post by speedstar »

I am interested in a Rocky chute mod that I saw from a fellow member, snoboy. He made a metal chute that lifts on top. Does anyone have more info on this? I would love to get a plan for this preferrably a CAD file.
Snoboy, can you help me out? Thanks.

User avatar

#8: Post by HB »

Devin, I merged your thread with snoboy's, but I'm not hopeful for a response from him. According to his profile, he hasn't logged into this site or Coffeegeek for over a year. You could try e-mailing him (his login +, according to his Coffeegeek profile).
Dan Kehn


#9: Post by speedstar »

Thanks Dan. I appreciate the help. Hopefully we can get in touch with him.

User avatar

#10: Post by mute »

I'd love some type of chute similar in design to the aforementioned metal one, the plastic chute is a real pita. I wonder if we could convince someone to manufacturer a couple and do a group buy..