Building the Ultimate La Pavoni Europiccola - Page 10

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
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drgary
Team HB

#91: Post by drgary »

Wiring Completed

Edit: Warning! Be sure to insulate the switch contacts, which can touch the metal base and cause a short!

I completed the wiring today according to Ray's diagram. The PTFE shim around the power cord keeps it away from the heated bottom boiler plate. After wiring and before plugging it in I tested from the spades on the power cord to make sure it was working as intended.



Pressure Test

This is always an exciting moment. You hope everything will work. So I plugged it in, turned it on, and the GFCI didn't trip. Good!



I was happy to see that the indicator lights both went on. They are fully colored unlike what you see in this iPhone photo.



Another exciting moment is when the manometer indicator starts rising.



As it reached 1.0 bar and beyond, the OPV started steaming intensely. The heating element light didn't go off, but I expected this may have been because of a high pressurestat setting combined with pressure venting too intensely. I powered down, unplugged, and took the Teflon mushroom out of my 1961 Europiccola and installed it. It still vented too soon.



I also noticed a bit of steam had released on the bottom rubber plate at the pressure fitting for the PSTAT. I went out to my tool bench and used leather punches to create shims for the OPV spring so it wouldn't release as soon. Two shims almost 4mm thick each did the trick, using the vintage spring and ball bearing. The Teflon mushroom doesn't seem necessary on these machines if you shim carefully. Don't overdo it or you'll defeat your OPV. This is something you do at your own risk.



I also picked up a second 17mm wrench to tighten the pressurestat and that worked. I dialed the pressurestat down counterclockwise and achieved my target setting of on at 0.8 bar and off just below 1.0 bar. The heating element light goes on at 0.8 bar and soon turns off. So that's working too. The smell of the steam tells me it's now time to descale. It is so ready!

There are still some mods to do, specifically I want to size the brass rod for lever pins by spinning it under steel wool, then cut it in lengths and thread the pins for stainless steel acorn nuts. After that I want to try Rich's (oldnuc) idea of a roller bearing with shims for the rear slot. I'm also thinking about what I want to do for measuring temperature at the group, whether using temperature strips or mounting a digital thermometer.

At the moment, though, I'm really glad I've got it working.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

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drgary
Team HB

#92: Post by drgary »

Thorough Boiler Cleaning

Things seemed all ready to go for a first shot, but the steam smelled metallic. I tasted some water from the group and there was a hint of petroleum oil taste. Possibly some penetrating oil had gotten inside the bottom boiler lip when I was struggling to loosen the flange. Several cleanings using Pulycaff took care of that problem. In the process, though, the machine got hot from refills and reheatings.

The GFCI tripped a couple of times. I removed the bottom plate and noticed accumulation of moisture but couldn't tell where it was coming from. Leaning it on its side for inspection revealed a paint failure.

Paint Failure

Here's what I saw this morning. The paint had softened, wrinkled and lost its surface at the edge when I leaned the machine over to inspect the bottom while it was hot. This is going to need a repaint. The product I used has a maximum temperature of 200°F. I didn't think the base would get that hot, but here's the evidence.



This paint doesn't meet the spec for this project.



After the machine had cooled overnight I was able to inspect for the leak underneath. The Pulycaff used for cleaning had created a fine powder over the PSTAT, revealing a leak at the pressure fitting. (I hate pressure fittings. There's got to be a better way to seal these things!) I wrapped some ptfe tape around the knob of the male pressure fitting to create a softer material for sealing, punctured a hole in the middle and made sure it would stay open, realigned and retightened. Fingers crossed. I'm going to test this again before disassembling to repaint the base. This time I'll go to an auto supply store and will source a high temperature rust sealing paint. It won't be hammertone, but since this isn't intended to be a faithful restoration I can choose a creative color that fits our kitchen.

Meanwhile I've got another 1st gen Europiccola on the bench that will be a more traditional restoration. I only need to assemble it and wire it more simply, but first I'm going to check and make sure that its hammertone won't fail when hot. I may be repainting two bases! This is a version 1.4 (1964-68) sourced from H-B member rotchitos (Vincent).

Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

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drgary
Team HB

#93: Post by drgary »

Although I will repaint, this morning's coffee was made on my ultimate Europiccola. Temperature reading at bottom back of the group went very high, but the coffee wasn't burnt. This tells me about its heat sink properties. Feel of the pull even more rock solid than a second generation Cremina.* Keep in mind that the lever is longer and the base is heavy, cast aluminum, and there's absolutely no "give" under pressure. The group internal temperature may be more stable than a 2nd gen Cremina, also, although only measurement will tell. I will do a follow up temp study thread and will probably adjust the PSTAT lower to accommodate darker roasts too. (With half pumps I'll still be able to fully heat the group for lighter roasts.) That thread will give a sense of how to tune this hybrid machine.

Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

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[creative nickname]

#94: Post by [creative nickname] »

Congrats on getting it up and running! A first gen Pavoni tuned to be stable at idle, without venting steam out of the OPV, might well be the ultimate small office or vacation machine. I look forward to the temp studies and also to seeing the final paint job!
LMWDP #435

forbeskm

#95: Post by forbeskm »

Beautiful! You are only inspiring me to buy more Pavoni's!

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gunman45

#96: Post by gunman45 »

Thanks for doing all of the legwork on this........... :D

Now that my Cremina is up and running I will mod my La Pav for use in my camp trailer for the up-coming season. I will not need to add the lights as I will use the one red on my Generation 2 La Pav.
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Larry - LMWDP #536

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drgary
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#97: Post by drgary »

If you're talking about a 2nd generation La Pavoni, it has such a different group it's off topic for what's discussed here. 2nd gen is still a good machine and just fine for travel, of course. You could start another thread of mods done on your 2nd gen where the group is a much less efficient heat sink, so it would need to be tuned and maybe used differently.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

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gunman45

#98: Post by gunman45 »

I cannot see how the Gen 2 would require a different setup. Changing from a dual heater to a single and the other components would be the same. Of course there is more thermal stabilization with the brass sleeve but its the single wattage heater/pressurestat setup that interests me the most and your upgrade would would work just fine on a Gen 2. For that information I thank you.
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Larry - LMWDP #536

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drgary
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#99: Post by drgary »

You're bringing up an interesting discussion and a project that's worth trying, but it's different enough I still believe it deserves its own thread. You could certainly link to the wiring we're trying here.

Here's another way it's different. According to Robert Pavlis, the group can't be heated by pumping water into it. Apparently steam enters the group so it easily overheats. It may be better run manually by toggling on and off. That can be done effectively as I wrote in this thread:

Reaching the Zen Zone with a Two Switch La Pavoni

But I'm not sure whether that group can be temperature stable without toggling off because I haven't owned a 2nd gen in a long time. You may find more information about this if you search threads about controlling temperature in a pre-Millennium La Pavoni Professional. Essentially that's the setup you're proposing, but without the larger boiler. People say those are prone to overheating. Perhaps you could set the PSTAT low enough, but at a certain point you're not going to get much positive flow into the boiler and steaming will be virtually disabled.

One could argue that the group on a Cremina resembles that on a 2nd gen La Pavoni, but if memory serves there are holes cast in the Cremina group that are filled in. Those may still be open in a 2nd gen Pavoni group. Since you have a Cremina and a 2nd gen Pavoni, maybe you can tell us.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

cpreston
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#100: Post by cpreston »

Could you comment on any differences in use/convenience/temp management between a current Millennium model and these early ones, after proper setup and assuming use of a thermometer? Is the current model functionally as good? I realize there is a lot of difference in mechanical quality.