RR45 conversion to stepless - Page 2

Grinders are one of the keys to exceptional espresso. Discuss them here.
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Postby danw2002 » Jan 16, 2013, 6:02 pm

Pics man, pics....i too have a fiorenzato, and was going to add a ring stop on the other side so that every other tooth would enage, so one side would engage, then half step latter the other side would engauge, giving me 2x more steps, have the new button and spring, just waiting to set up the drill press, as you can guess the location of the hole is very important, as it has to be Half tooth over from the other side to give the offset, so pics of yours would be nice to see if there is an other way of doing this....thanks.
I made my Fiorenzato grinder stepless using Macap parts. It took some tweaking but in the end it works well.

I attached the Macap notched-edge plate that was closest to the diameter of the outside of the upper burr carrier. this meant drilling and tapping the holes in the upper burr carrier where the mounting holes were in that plate. Then I mounted the Macap worm-gear so that it engages the notched plate. This took making some spacers, grinding some metal, and adding a spring; that was the hardest part of the job.

I really like the result.
What!?!?!, I have not had enough coffee...
Playin with beans in the PNW...

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Postby fishll » Jan 18, 2013, 1:07 am

The grinder I converted to stepless was the Brasilia/Rossi BFD very similar to the rocky, in fact it uses the same burrs. Its in no way comparable to the SJ. The hopper and upper burr carrier were one, which unscrewed. Teflon was placed on the threads closest to the hopper in about four layers.


Postby PaulTheRoaster » Jan 19, 2013, 2:55 am

I converted my RR45 about 7 years ago by simply drilling a hole through the plastic ring and threading a machine screw with a wingnut on top. I didn't use a tap to make the threads -- I let the screw make its own. It would be nicer to put in a threaded insert, but the plastic threads never wore out. I arranged it so the head of the screw contacts the top of the grinder body, and I attached a wingnut to the tip of the screw (with another nut and a drop of Loctite thread locker, probably blue, but possibly red).


Postby darilon » Jan 21, 2013, 5:16 pm

I think the biggest issue for the Rossi style grinders is in the sloppy fit of the upper burr carrier threads. It allows more upper burr movement than a single click on the adjustment ring. In fact, I bet the loose fit of the threads allows as much change in particle size as many clicks and just using a single screw on one side to pin the ring in place leaves the carrier at a tilt with a big difference in particle size being cut on one side than of the burrs than on the other side. The big advantages the Mazzers have are first that they have their threads cut to a tighter tolerance and second that they use the three springs to keep the carrier threads floating at the top of the body threads.

From this I could conclude (in a purely theoretical manner) that teflon tape or carefully tapping flat the threads in the upper burr carrier provide the biggest improvement in particle size consistency and overall grind quality. The stepless mods would be the next on the list. As an alternate to the teflon (or perhaps in addition) I think drilling holes in the grinder body to add springs like the mazzers have would be quite handy.

When I say tapping the threads flat, I mean carefully rounding them off so that they fit the body threads nice and tight, not actually flat, which would basically ruin your upper burr carrier. Having picked up a free Rossi style grinder (no badges, who knows what label it was originally sold under, but I think it's a 240v CC45 without any of the vents near the top of the grinder body), I look forward to experimenting with the various mods and comparing the grind quality to my mazzer Mini.

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Postby allon » Jan 21, 2013, 6:45 pm

I used my RR45 until i modified it by replacing it with a Super Jolly. Then I used it for drip for a while before modifying it again by replacing it with a Lido.

It's sitting idle now; not really worth the effort but I'm keeping it because its covered in sentimental stickers.
LMWDP #331

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Postby DJR » Feb 14, 2013, 1:30 am


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