Stepless mod for Rancilio Rocky- a cleaner approach

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

Postby F.M. » Dec 15, 2008, 2:08 am

I had my rocky taken apart today to do some cleaning. This was the first time I had taken the burr plate out, and while I was in there I noticed how simple the stepping mechanism was. Surely making this grinder stepless would be an easy mod! I took a break and did some internet research, but I wasn't too excited about some of the solutions out there... must be a way to re-purpose the stock design I thought. Here's what I came up with; Basically the index button now serves as a sort of "brake". Instead of pushing a pin into a hole, it presses a soft rubber grommet against the bottom edge of the hopper. You can turn the hopper with the "brake" on, but it takes both hands w/o beans- plenty of resistance. Press the "brake" button down and the hopper turns freely with no steps. The mod cost $5 and is not permanent.

This photo shows the stock parts and what I added. Sorry, I took this before I had everything figured out so it's not as instructive as it could be. From left-to-right:
1. new part: Stiffer spring which fits around the stock pin. PN# C510 by century spring, 1/4x1/2".
2. Stock pin with the e-clip. I removed the clip and flipped the pin over, so the blunt end faces up.
3. Nylon bushing that I purchased but ended up not using.
4. The stock index (now "brake") button
5. new part: Rubber grommet- this plugs into the top of the "brake" button to give it some grip on the hopper. When re-assembled, the springs are pushing the "brake" button with rubber grommet up against the bottom edge of the hopper, preventing the grind from drifting.

So basically, remove the e-clip, install the pin upside down, add the spring and rubber grommet, and re-assemble. The parts were $5 total from Ace hardware. The only other thing to note, is that when re-installing the hopper, you have to press down against the force of the springs while you thread the screws in. I'll post again in a week or so after some use, but so far it seems to work fine.

Image

wideawake

Postby wideawake » Dec 15, 2008, 9:26 pm

That sounds great! If you get a chance, could you post a picture of the mechanism assembled in the grinder, without the hopper on? Also, any chance you could give some instructions on how to get to the mechanism to do this mod?

I've been wishing for a while that my Rocky was stepless, and this looks like it might be the ticket.


Thanks again

Peter

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trzynkaa

Postby trzynkaa » Dec 15, 2008, 10:15 pm

A nice solution to the discrete grinder step problem.

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fredfal

Postby fredfal » Dec 15, 2008, 10:18 pm

F.M.

Really nice job! I also have looked at a lot of the other Rocky mods and, though they appear to work well, have been a little put off by the "hacked" look that many of them end up having.

This is a very simple, elegant fix.

Way to go!
-Fred

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F.M.

Postby F.M. » Dec 16, 2008, 12:49 am

Thanks guys. The mod is working excellent so far- no drift, and the grind is easy to adjust.

With some fresh beans, I got the best shots ever out of my machine tonight! It really is nice to have that added adjustability.

I'll pull it apart and take some better pics after finishing off this 1/2lb of beans. It's definitely an easy mod to install. If you guys are interested, I could be talked into picking up a few more of the exact spring and rubber gasket I used so you don't have to hunt for them.

earlgrey_44

Postby earlgrey_44 » Dec 17, 2008, 10:32 am

This mod has such a gigantic benefit-to-hassle ratio, I've immediately made plans to assemble the needed parts.

Thanks and congrats on the idea!
Trust your taste. Don't trust your perception.

Mark08859

Postby Mark08859 » Dec 17, 2008, 10:37 am

fredfal wrote:F.M.

Really nice job! I also have looked at a lot of the other Rocky mods and, though they appear to work well, have been a little put off by the "hacked" look that many of them end up having.

This is a very simple, elegant fix.

Way to go!


I agree about the "hacked" look. Very ugly. Something that is transparent would be the right way to go.

ChrisC

Postby ChrisC » Dec 17, 2008, 3:31 pm

Hi FM! Great job. I have my Rocky hacked for stepless already using a very functional albeit less aesthetically pleasing method, but now I want to do this. I'd be very interested in some kind of group buy for springs and gaskets -- please keep us posted!

And again, great work!

Chris

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Psyd

Postby Psyd » Dec 19, 2008, 3:41 pm

F.M. wrote:2. Stock pin with the e-clip. I removed the clip and flipped the pin over, so the blunt end faces up.


Uhm, isn't the blunt side normally up? And the pointy end in the notches on the hopper?
5. new part: Rubber grommet- this plugs into the top of the "brake" button to give it some grip on the hopper.

So, the grommet goes into the hole in the brake? Basically 'lining' the hole and resting on the top and bottom of the 'brake'?
So basically, remove the e-clip, install the pin upside down, add the spring and rubber grommet, and re-assemble.

Does re-assemble include replacing the e-clip?
I agree, some pics of it assembled would go a long way into my understanding of the process.
I never was really good with written instructions. ; >
Espresso Sniper
One Shot, One Kill

LMWDP #175

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F.M.

Postby F.M. » Dec 23, 2008, 6:07 pm

Things are working great. No drifting, and the ability to tune the grind finer has improved my shot quality quite a bit. The grinder is still easy to adjust too.

If there is any downside, it's only that since this is a modification, it gets the job done great but the button doesn't have the precise feel of something that was engineered from scratch to do what it's doing. Hope that makes sense! Lets put it this way, when you're not pressing the button you can still move the hopper with both hands. And when you do press the button there is still some resistance. But otherwise it does exactly what I wanted it to do. Plus, this mod is totally reversible, only costs about $3 and takes 10 minutes to do.

If anybody wants the exact spring and rubber gasket I used, email me at emailsucks98 (at) yahoo and we'll figure it out. As said, it's only about $3.

No photos, but below is a graphic depicting a side-view section of the parts.
Stock Parts:
A) Indexing button
B) Shaft pin
C) e-clip
D) spring

Addition parts required for modification:
E) Rubber gasket
F) Additional Spring

Modification process:
1) Remove all beans from grinder. Set grinder to "0" setting.
2) Remove the three flat-head screws from the finger-guard inside the hopper
3) Remove finger guard from hopper and lift hopper assembly from grinder.
4) The grinder indexing mechanism is now exposed inside the grinder. Push down on the metal pin while lifting up on the indexing button, inside the grinder. This will allow you to remove the indexing button.
5) Remove the shaft pin with e-clip. (you can leave the stock spring, part #D, in the hole within the grinder)
remove the e-clip from the shaft pin. The e-clip will not be re-used.
6) Put the shaft pin back in the grinder, but upside down, so the pointed end goes into the hole where the spring #D sits.
7) Slide the additional spring over the shaft pin. This will create additional upward pressure on the hopper.
8.) Press the rubber gasket into the top of the indexing button. Maybe some glue is a good idea.
9) Install the indexing button in it's original location.
10) re-install the hopper, finger guard and screws. You will have to push down on the hopper to compress the spring, as you thread the screws in through the finger guard.

Image