1: Overview - La Pavoni Lever Espresso Machine

[@kvitoroulis]

This is outstanding John, thank you.

[@BrucePappas]

John, this is an excellent explanation of the differences between Gen 2, 3, & 4 groupheads (GH)and how they work. I hope ALL La Pavoni lever machine owners watch this. A few observations (everything mentioned here regarding Gen3s also applies to Gen4s): 1. Upper chamber: The top of the GH is important in the heat-up process. Gen2s are steam-heated, Gen3s water-heated. When the lever is at its lowest position, steam or water is allowed to fill the top of the GH, i.e. the upper chamber. Water-heated Gen3s tend to run cooler for this and a few other reasons. 2. Lower chamber: Gen2s and Gen3s have different mechanisms to fill the lower chamber: - In Gen2s, water enters the lower chamber directly from the boiler at close to boiler temperature. The only way Gen2 owners control the temperature of water that enters the lower chamber is by switching between the two heater elements (if it has 2) or by switching the machine off (or the pressurestat switches off the element if equipped with a pstat). - In Gen3s, water that enters the lower chamber is tempered by the GH. First it swirls around the outside of the sleeve and then enters the lower chamber from the top of the upper chamber through a tunnel on the exterior of the sleeve, as you noted. 3. GH temp: In all generations, GH temperature is important and worth managing. Once the water enters the lower chamber and comes in contact with the GH, GH mass will further heat or cool it, and thus, establish brew temp. Gen4s have more GH mass to affect water temp. I love having a model to show how our machines behave differently. They are truly "different animals." Thanks for all your hard work.

[@Stelios.Posantzis]

9:17 Steam or air are compressible: once they reach equilibrium with the steam/air in the boiler, water from the boiler will stop coming up to the head. If for some reason you can increase the pressure in the head (e.g. by decreasing the volume through piston action), then there's only one way for the steam/air to go: back through the tube. If you decrease the pressure in the head (e.g. by increasing the volume through piston action), the opposite will happen. This is my understanding based on your presentation.

[@JohnMichaelHauck]

Stelios, it is all a bit confusing, but I think your comment is consistent with my understanding. I'll restate your comment in my own words to see if I am understanding your point. Raising the lever raises the piston, which decreases the volume in the chamber above the piston, which forces any water, air, steam out of the chamber above the piston and back into the boiler via the siphon tube. Lowering the lever lowers the piston, which increases the volume in the chamber above the piston, which draws water from the boiler into the chamber above the via the siphon tube. Let me know if you have any concerns or questions.

[@Stelios.Posantzis]

@@JohnMichaelHauck In my comment I was always referring to the volume (and pressure) of the chamber above the piston. I also corrected the time. Apologies if I caused any confusion. I agree with what you wrote except that you have one typo in : "Lowering the lever lowers the piston, which decreases the volume in the chamber above the piston" It should be "increases" and not "decreases" of course.

[@JohnMichaelHauck]

@@Stelios.Posantzis Thanks for catching that! I edited the reply to fix yet another silly mistake of mine.

[@Stelios.Posantzis]

@@JohnMichaelHauck I dare not think how long these CAD models must have taken to make. Their precision is very impressive. A very useful guide for choosing between models and identifying which model corresponds to a particular second hand machine.

[@enekogomez9038]

Thank you, thank you, thank you!!!.... I'm a lover of these machines and I fancy doing the maintenance by myself. This is the definitive tool to ease my repairing and to know exactly how the machine works, that is mandatory to make a good maintenance and to understand and know what are the spare parts to change if needed. Thank you again.... now, I can't understand how I lived until today ignoring this application.😉

[@JohnMichaelHauck]

This makes me happy. Cheers!

[@benhetfield]

Thanks a lot! I've been searching for gen. 2 schema without success, until this video; even more helpful than schema the whole mechanism is explained and can be seen functioning. Thanks for the time passed creating this and for sharing it!

[@JohnMichaelHauck]

Cool!

[@esyu-eq4hw]

Great explanation! I am a big pavoni enthusiast as well

[@athhehetha2983]

awsome video! I would love to see a comparrison of the first generation La Pavoni.

[@JohnMichaelHauck]

Joseph, Check out the play list kzbin.info/aero/PLPX9KWMNFMwNk_aBK7plrFBF1VJx0OMVw You might find what you are looking for!

[@toddmacon670]

Awesome. Truly, awesome.

[@JohnMichaelHauck]

Thank you kindly!

[@CyberGene]

Nice! It's the first time I understand how exactly the La Pavoni works, thanks! I'm wondering though, on 3rd generation, once the lever is down, it's possible that the chamber above the piston might get full of water? Then, when you lift the lever, how is that water going to escape the chamber? I can't imagine it. On the second generation the steam will push the water back to the boiler but there's nothing like that here. To me it seems if there's trapped water, its only path is through the piston rod gasket at the upper side of the head. BTW, on my La Pavoni some water started leaking from above when I lift the lever before making a shot, so my theory is corroborated. I guess if all is sealed properly, water can't enter the upper chamber because it will be hermetically sealed.

[@JohnMichaelHauck]

Glad you like it. To address your question, on the 3rd generation with the piston down, water does indeed fill the area above the piston. When the piston is raised, this water travels up over the top of the sleeve, through the neck and back into the boiler. Take a look at the top edge of the sleeve, and you will see what I think look like "battlements" on the top of a castle wall. Maybe some of the other videos in this playlist will help. kzbin.info/aero/PLPX9KWMNFMwNk_aBK7plrFBF1VJx0OMVw

[@CyberGene]

@@JohnMichaelHauck, ahh, you’re right. Indeed that’s the water path as it seems. All makes perfect sense now. Thanks again!

[@panosswiftsport]

​@@JohnMichaelHauck so as you have described with 3rd gen grouphead as the lever moves up, the user will feel difficult to raise the lever because of traped water, and the lever will go alone quick down if you leave it, right?

[@JohnMichaelHauck]

@@panosswiftsport Correct. The user will be raising the piston against the boiler pressure. It does not take much effort, but it does lift the front end of the machine a bit if you don't hold it down with your other hand. As you said, if you let go, the lever drops quickly. However, once the lever is all the way up and the water fills the area under the group head, then the pressure equalizes and the lever stays up by itself (provided the coffee grinds are fine enough to prevent the flow of water at low pressures). An interesting related phenomenon is that this works backwards. When you turn off the machine, there is no air* in the boiler but just steam. As the steam condenses into water as the boiler cools, it creates a vacuum. The pressure relief valve on most machines will open at this point and let air in. If the pressure relief valve is an older design or is stuck closed, then the vacuum causes the piston (and lever) to rise. * The reason there is no air is because opening the frothing (steam) valve lets out the air and all that is left is steam. You need to realize steam is not hot air. It is vaporized water that condenses (contracts) back to liquid water when cooled. Modern pressure relief valves take a while to close, first letting out a lot of air. So in practice, when you turn on your boiler, after a few minutes you will hear air escaping from the pressure relief valve for a few seconds before is closes with a satisfying click. If it does not close, whack it with a wooden spoon. Cheers!

[@PyMeH]

Respect!

[@gaarithwilliams2353]

Hey John- could you please post those links in the comment section or description? Typing in the links from the video is not working

[@JohnMichaelHauck]

Gaarith, This links to the document: bit.ly/LaPavoniCadGuide From there you should be able to get to all the other resources, including the interactive CAD model.

[@윤상찬-i6s]

Thanks for ur info. very helpful :)

[@JohnMichaelHauck]

Awesome! There is more here kzbin.info/aero/PLPX9KWMNFMwNk_aBK7plrFBF1VJx0OMVw

[@sidbokhani3427]

Can you provide me full details of this machine , I want to know about its water storage capacity nd Heating temperature time .

[@JohnMichaelHauck]

Check out LaPavoni.com

[@adambromley6972]

Hi I have a question I can’t seem to get answered anywhere else, I seen this review on Amazon: “Then I noticed that after using it, there was a puddle of water underneath. La Pavoni sent me to Thomas Cara in San Francisco, and said he was their representative. HE curtly said he was NOT their representative. But he described a defect in the Stradivari design - the heating element is made of stainless steel and the bottom fixture is brass - so they cool at different rates and frequently leak like mine was doing. So there is no good fix for this $800 espresso maker.” That’s a quote from part of the review, while I’m not interested in a Stradivari I am looking at getting the esperto abile I’ve read the esperto abile has the same “base” as the Stradivari but with a red accent, I’m not sure what other similarities they may share but I’m worried this “design flaw” would be apparent in the esperto abile model as well Basically I’m other words, do you know if the esperto abile has a stainless steel heating element and a brass bottom fixture? I’m not sure what the “bottom fixture” even would be or if this is even a credible complaint. Do you believe there is any truth to this? And will it happen with the esperto abile if I buy one?

[@JohnMichaelHauck]

Adam, I'll try to help. This is what I think he means by "heating element": coffee-sensor.com/product-category/la-pavoni-parts-and-accessories-custom-made-from-coffee-sensor/heating-elements/ This is what I think he means by "bottom fixture" (I call it a "boiler ring") coffee-sensor.com/product-category/la-pavoni-parts-and-accessories-custom-made-from-coffee-sensor/boiler-rings/ The boiler ring is screwed around the bottom of the boiler. The heating element is attached to the boiler ring with three bolts. Water can leak from where the two heating element connectors protrude from the heating element. Water can leak from the interface of the heating element and the bottom of the boiler. Water can leak from the hole which is connected to the pressurestat with small pipe. I would strongly suspect (but I do not know for certain) that the boilers/heating elements/boiler rings of the Esperto Abile and the Stradivari are identical. I cannot tell you what materials are currently being used in new products. I can tell you that from all the online forums I monitor, I have not read about a chronic issue with water leaking from the bottom of the boilers - neither new machines nor vintage models. Personally, I own 3 different recent generation La Pavonis (including a 2020 Stradivari) and have not experienced any leaks on the bottom of the machines. I would guess that a leaking new machine has more to do with one of the three bolts being a bit loose. La Pavoni has done a remarkable job of continuous product improvements since 1960. Maintaining and repairing the machines is easy enough. I hope this helps.

[@adambromley6972]

@@JohnMichaelHauck helps a bunch thanks! :)

[@duncan.g.burton]

Incredible CAD’s John. Quick question, is it possible to Pull a shot using Flow Rate profiling ? Thank you

[@JohnMichaelHauck]

Duncan, Let's say you want to start with 1 bar for 8 seconds, then 7 bar for most of the volume, then finish with 5 bar, you can indeed do it. What you need to do is press the lever down softly for 8 seconds, then press pretty firmly for most of the volume, and then back off a bit for the finish. Now you will ask, how do I know what "softly" is for 8 seconds? Good question! Well, let me ask, why you want 1 bar? Because it taste good that way you say. Fine, I say, then figure out over time what amount of "softly" gives you the best tasting shot. In other words, use "feel" to dial in your shot profile, not numbers. That may be, you reply, but my question implied numerical precision, and you dodged that in your answer. Well, then, I reply, you could trick out your La Pavoni with a "pressure profiling kit". This is an analog pressure gauge that connects to the piston. You can then watch the needle as you pull your shot. Mind you, for the 8 seconds you will need to watch a timer too! Such a kit can be purchased here: coffee-sensor.com/product/coffee-sensor-full-piston-pressure-kit-for-the-la-pavoni-europiccola-pre-millennium-and-millenium-machines/ Now if you want a machine that can run a precision profile with the touch of a button, I am smitten by the products at decentespresso.com/ Tell me if I answered your question somewhere up there.

[@duncan.g.burton]

@@JohnMichaelHauck Thank you John, your information is great & I’ll give it a go. It’s interesting that some semi automatic machines are adding this flow control & the most basic machine has had this feature for nearly 70 years. I’d never replace my Pavoni, it’s just great and stunning to look at. The only thing I wish the Pavoni’s had was a heavier base, I think the mk1 or mk2 had a metal base. Many thanks again 👍☕️🇮🇹

[@ozespresso]

Great Video! I love the CAD! Is it possible to have the file so we can 3D print it? Thanks!

[@JohnMichaelHauck]

Well of course! However 3D printing requires slightly different geometry. I created a simplified version for this very purpose. bit.ly/LaPavoniCadPrintable You should be able to export directly from this link to your format of choice. Cheers!

[@adambromley6972]

Is the CAD model Canadian? Do you have to get somewhere other than their website to get that?

[@JohnMichaelHauck]

Adam, I'm confused! The model should be available internationally. Can you see it at bit.ly/LaPavoni ? If not, try this full URL cad.onshape.com/documents/4833676df7d2a808ac4b52b7/w/1779c4496f69618947b539b5/e/75f2654cbbb785c3812333d2

[@adambromley6972]

@@JohnMichaelHauck sorry I was confused too I’m just wondering what the CAD model is? I’m the begging you say “this is the la pavoni cad model” I was just wondering if cad means Canadian or maybe it meant something else

[@JohnMichaelHauck]

Adam, Forgive me, I am a hypocrite. I take a dim view of people who throw around three-letter acronyms as if everyone knows what they mean. Here I am doing the same thing. I am using the term "CAD" in this case to mean "computer-aided design" (en.wikipedia.org/wiki/Computer-aided_design). Over the course of many moons, I took physical measurements of various La Pavoni lever machine models in my possession and then "drew" them in a three-dimensional space on a computer. For example, the lever rod is a metal cylinder. So I drew a circle on the computer of the diameter of the rod (12 mm), and then "extruded" the circle into a cylinder of the length of the rod (160 mm). I then drew the black handle (a bit more complicated) and attached it to the rod. Then I added the fork on the other side. Once I started modeling the "e-style" retaining clips for the pins on the fork, I found I had descended into a rabbit hole with no escape. So I undertook to model the entire machine, including switches, wires, logo, and pressure gauges. I'm still not done, but I've completed enough to share this computer model of the La Pavoni machines in these KZbin videos. I hope I answered your question. - John

[@adambromley6972]

@@JohnMichaelHauck completely! And cudo’s to you for putting in the work this really helped me out and I think it was WELL worth the effort. You are a legend