OK, so I finally got around to doing some work on my trusty RR45 grinder. I know it's not the best out there, but I've been getting great espresso from it even with it's limitations, so I put any changes off. My original intent was to just put in new burrs, since I bought it used (commercial use) and I know the burrs couldn't be sharp. I decided to do a mod at the same time to double the indices to 80 from 40. The index mod came off great, and the burrs seemed great too, but I'm not too happy with the taste anymore. I broke the new burrs in with 11 lbs of minute rice first. The taste was a little sour. I could improve it some by bumping up the temp, but it's not anywhere near as good as where I started. Is's a 2 dimensional taste, where before I was getting lots of subtle flavors. I even tried lightly wire brushing the burrs to get any remaining burrs off, but only saw a slight if any improvement. I notice when grinding that it grinds MUCH faster now, like 3x. The burr machining is different from the original which I think is contributing as much as the added sharpness. The speed has added static too, which I never fought before (although it is listed as a problem with RR45's). The static is so bad that I can't knock the fines down. I'm almost wondering if the static is separating the grounds in a bad way within the doser. Not sure really where to go from here. If it doesn't get better, I guess I can just re-install the original burrs, but the new ones must be better eventually, right???

Here are some pictures:
Original carrier


Old burrs top, new bottom. The grind pattern is different. These are the burrs for this machine, though.


The new indexing disk


Complete upper carrier with new burr and indexing disk


Loaded on the machine


By the way, this mod required no changes to any other parts. It just pushes the hopper up by the thickness of the disk. I did add a stronger spring to make the detents very tight.

Any ideas of how to proceed short of just putting the old burrs back in the machine?

Thanks,
Jim

If you are single dosing try adding a couple drops of water to the bean dose before grinding. This should eliminate the static & you can determine if that makes any difference or not.

I don't single dose, so have been trying to decide how best to spritz the beans when I thought of a different approach last night. This morning I let the grounds sit for 5-10 mins before dosing. MUCH different results! When I tapped the sides of the doser, all the grounds fell down cleanly and The resulting pull was really good and the taste was back where it used to be if not a little better. I was even able to open the grind slightly, where before I had been grinding finer than with my original burrs.

I had seen in various other posts that static can have an effect on the result, but I was suprised it was so dramatic. It must have been filtering out the lightest fluffiest grounds when I was grinding and dosing immediately, resulting in an unbalanced flavor.

Jim

This is a curious taste observation. I have 2 Rossis that aren't seeing much actiion at the moment but when I use any of the electric grinders "personal" use I usually grind a dose then brush down those grounds before I dispense to reduce waste. But since I put a Robur on the counter at the shop the taste difference and shot quality is vastly different from the SJ. But i think now after reading your posts a personal taste test may be in order between my RR with fresh blades and the SJ with fresh aftermarket duraniums, of which I don't think these duraniums are really better than stock blades...too much taste inconsistency.

I like indent plate upgrade! For almost 4 seconds I thought I would do the same thing for mine... then decided I don't have the patience to drill 80 holes with a horsehairs width of tolerance.
I just ordered some new burrs for mine, and will follow your lead on the break in.

zombiecoffee wrote:I like indent plate upgrade! For almost 4 seconds I thought I would do the same thing for mine... then decided I don't have the patience to drill 80 holes with a horsehairs width of tolerance.

LOL! I would't try it either without a CNC mill! Realistically, though, only like 4-5 are really needed for the espresso range. That is probably doable with a hand drill and patience.

I tried really hard to get 100 holes, but they were too close.

Jim

OK, I lived with the new burrs for 1 lb of coffee. It was definitely drinkable, but not up to where I thought I was before. To prove if I was crazy or not, I just switched back to the original burrs. Now I'm convinced the shots were much better with the old burrs. There was a lot more depth of flavor to the shot. The static issue disappeared. The grind time also went higher to what I had before, I think almost 3x the new ones. And I had to open up the grind (from burrs touching) a lot, back to the original position. I'm sure I broke in the new burrs enough that the taste should have been closer if it was possible. I really think now that the completely different cutter pattern has a huge effect. Are my old ones original Rossi's (unavailable now) and was there something special to the shape? Has anyone else seen this before with Rossi's? Is it possible that aftermarket burrs take a decent grinder and push it down a notch?

If I'm happy with the shot taste, is there any need to even look into new burrs (which is the standard recommendation for a used grinder)? With where I'm at now, I would say no...

Oh, BTW, I am really enjoying the finer adjustment with the indexing upgrade. It makes this grinder worth hanging on to now (but with the old burrs!)

Jim

I really like the 80 hole mod you've done! That's really the only option other than modding stepless now that the 80 pin collars are out of production. WRT your burrs, I just pulled the upper carrier from my CC45 and can confirm that the burrs in it are the same as your new ones. I *think* the old ones were similar, but as this grinder was a rescued unit from a restaurant fire, I pitched the old burrs out immediately (they'd been sitting for months with coffee on them after having who knows how much water on them when the FD put out the fire). My experience is that the upper burr carrier is threaded much sloppier than my Mini and some teflon tape can fix that up nicely.

darilon wrote:My experience is that the upper burr carrier is threaded much sloppier than my Mini and some teflon tape can fix that up nicely.

When I looked at the original configuration, I noticed that with the pin fully engaged in the plastic hole, there was still slop between pin and hole. I made the holes in the new part smaller to eliminate the hole slop. The stronger pin spring helps to prevent movement too.

Thanks for the look at your burrs. It would be interesting to see what others have in theirs.

Jim

Just bumping this up. Anybody else familiar with the Rossi who can offer some thoughts? Still seems to me that the replacement burrs are no match for the OEM design...

Jim