drgary wrote:That's very well done. I like the ability to tilt the display upward with the brass tab.

Thank you!

drgary wrote:You've also found a convenient way to attach that tab to a nut that screws into the boiler of first version machines.

Actually, the OPV assembly is the same (except for the part that screws IN the boiler) in every version of the Europiccola since 1965 up to today, including current Millennium models. I placed the bracket sandwiched between the OPV base and the cup. It's a totally reversible mod, too!

drgary wrote:Since you've asked, If I had my druthers I would fashion a clamping ring that fits on the neck of the group and attach an upturned metal mount like you've done. Displaying the readout just behind the group seems like a cleaner look. It's one I poached from the manometer placement of my Lady Duchessa.

I did have an idea to place it as you did between the group and boiler. But, aside from the fact that it is rather complicated to come up with some neat and clean looking clamping ring that would not scratch - SACRILEGE! - the chrome of the machine, I did have the feeling that it could interfere with filling the boiler, as it would have been too close to the water cap. There's the manometer already cramming up things, I didn't want one more...

pizzigri wrote:I did have an idea to place it as you did between the group and boiler. But, aside from the fact that it is rather complicated to come up with some neat and clean looking clamping ring that would not scratch - SACRILEGE! - the chrome of the machine, I did have the feeling that it could interfere with filling the boiler, as it would have been too close to the water cap. There's the manometer already cramming up things, I didn't want one more...

That's a matter of careful placement. That spot works on my Cremina and Pavoni.

drgary wrote:Not so much with the type of machine being discussed in this thread. You can set the PSTAT so boiler temperature cruises below desired brew temperature for everything but the coffee you brew coolest. Then use half-pumps to raise group temperature to the start temperature you want for that coffee. This allows you to brew with temperatures tuned to different coffees back to back. Generally that setting on a La Pavoni or Olympia Express Cremina is about 0.9 bar.

This is not my experience with a pre-millennium, steam-heated group. My PSTAT is set at 0.6 to 0.7 bar and the group never settles at a cruising temperature, it just goes on getting hotter and hotter, although slowly with the addition of a thermal-break gasket. My solution is to lift the lever as my group digital thermometer passes the target temperature for a particular coffee. If I want to pull a second cup, I turn the machine off, cool down the group with a frozen OE 3rd Shot heat sink, and repeat the process.

I stand corrected. This is right.

My PSTAT is set at 0.6 to 0.7 bar and the group never settles at a cruising temperature, it just goes on getting hotter and hotter,

I suggest that this is thermally impossible. The group will approach some temperature less than the boiler and then stop getting any hotter.

I agree that if boiler temp is fixed by a pressure stat setting, then monitoring and manipulating group/portafilter/coffee temp is going to be useful in adjusting brew temp.

Caution: if a thermometer is using a thermocouple (vs a RTD), then you cannot extend the leads with copper wire and get accurate results. I don't know which one is common in low cost household thermometers.

I suggest that this is thermally impossible. The group will approach some temperature less than the boiler and then stop getting any hotter.

I meant for all practical purposes. I have measured group temperatures as much as two hours out when experimenting with various materials for thermal blocks, and although the rate of growth becomes very slow I don't recall that the group ever ceased getting hotter. I agree that eventually it would find an equilibrium point, but that is a long time to wait for your morning coffee. Not to mention that you wouldn't much enjoy an espresso pulled with the heat sink at boiler temperature.

I did some measurements (using masking tape and an IR thermometer) and found that group exterior temperature stabilized at ~101C after ~30 min. Given that I don't use steaming, I wonder if I could adjust the pressure relief to a lower temperature where the boiler and group would stabilize at a temp suitable for brewing - no temperature surfing needed.

I find the flow/pressure attributes of the Europiccola interesting - but temperature management is a mess.

If you place a thermocouple inside the group at the top of the coffee cake, when the outside is 101C, what's the temp where brewing takes place? With my Millennium Europiccola (different model, I know) and my Cremina, when pulling shots with very light roasts, external group temperature will often exceed 100C and the coffee isn't burnt.

My experience has been similar to Gary's. On the Caferina, which is like the early brass-sleeve Pavonis, I can get great shots with the group temperature measured right around 212F (measured at the back of the group). This is with C+/FC coffees, not light roasts. Light roasts I flip the switch to massimo, and pull shots closer to 220F as measured at the back of the group. There is a lot of variation in temperature from the front to the back of the group, so where you measure can make a lot of difference.

With the outside of the boiler at 113C and the outside of the group at 101C (measured on the side), I see no source of any brew water at ~93C (about what I like).

Additionally, with the group cooler than the boiler, I expect a flat or more likely rising temperature profile during brew - but I prefer a slightly declining profile. Maybe if I significantly lowered the boiler temperature and added a group heater. And then did measurements to correlate boiler and group temperatures to brew temperatures/profiles.