I don't have a gauge on my PV Export piston. What I do have is a pair of rubber bands wrapped on the lever yoke, so I can manually increase the pressure, above that which the spring produces, by standing over the machine and pushing down directly on the piston rod via the lever yoke and cotter pin. I'm not sure the cotter pin likes this, but I have been producing some frothy little shots. This is faciltated by the fact that the Export seems to have a perfect center of balance - I can pull shots with one hand without the machine moving or tipping. I'll try to post some video of this interesting procedure sometime.

I just pulled a doppio Organic New Guinea SO, and I was high as a hummingbird (to quote timo) on the first sip...

PC

Great stuff,
Smaller pre-infusion, ramp up the pressure, back off on slow shots, pull harder to slow down fast shots-- Who would have thunk it--!! Dial in my arm to 135!!! Done.

Thanks guys

GreatDane wrote: I have to figure out how to load video on this sight. I'll go ahead and load some still pictures. John and I went through more than a pound of coffee today! I must say, we had fun! Oh and I learned a lot!

Afternoon Les. Just noticed the above quote.

You need to load your video on google or youtube first (I am assuming you were trying to use YouTube from the orphaned tags in your post).

Once it is uploaded on Google or YouTube, you have a link that will open the video in your web browser. Copy that http link from the page or your browsers address bar if you are playing the video.

Go to HB, create a post. When you want to insert your video, type either '[gvideo]' or '[youtube]' (depending on which one you used), paste in that url you got form the web page then close it with '[/gvideo]' or '[/youtube]' and it will appear. Remove the preceding and trailing ' in my post when you do it for real.

I.E.

'[gvideo]http://xxxxxxxxxxxxx[/gvideo]'

Alchemist,

The machine made it home for the holidays .

This has been a great experience. I never imagined when I joined this forum that I would be sending a coffee machine to another country to be experimented with.

I have used the mod a few times and now see that 9 bar is a bit more than what I was pulling at. I think I was more around 7 or 8 bar. Now as Mogo would say, "I have dialed my arm in". And the resulting shots are a better. It is a great training tool. I wonder if the piston can be removed and installed on another pavoni.

I usually use my chrome europiccola at home. I am finding that the shots are a bit different on my this pavoni ambassador (modded). Not because of the mod, I remember they were always a bit different. Results from levers, even though they may be same make, are all a bit different. Still great coffee but somehow different.

Thanks for the great mod. I will continue to experiment with it and post some more observations.

Happy holidays,

Also a big thanks to Greatdane (Les) for the lever handle. Looks and works perfectly.

So now it has been a month with Alchemists wonderful mod. My arm is dialed in and i think even a bit stronger. The 9 bar pressure is quite high and takes a bit more muscle than I expected. I have used the machine every day for the past month and it has produced wonderful results. Two espressos every morning. I have had a guest.

It is a blast to see the gauge show the amount of force exerted on the coffee. And it is fairly impossible to keep the force consistent throughout the pull. But it has been an excellent guide and I can now be sure what a 9 bar pull feels like.

But I find that I am always adjusting my pull based on the variables in the coffee. Pulls are adjusted even along the way depending how the coffee is flowing out of the portafilter, the 9 bar rule only works with a specific grind or tamp and i think a good espresso is pulled by a barista who understands the flow as well as the grind and adjusts the pull along the way.

Still love the zen feel of a totally manual machine (ie no spring) with a stepless manual Zass grinder. But for more than one or two shots in a row I give my zen a rest and use my faema Urania. I can pull two doubles and steam milk all at once. La Pavonis are not built for speed but I think they enable a user to find the shots best suited to his/her preferences.

Yesterday I retired the Modded ambassador and began to use the europiccola again. Missed using my sculpted bronze portafilter that seems to only fit into the eurpiccola. Well maybe retired is a bit strong, perhaps I am just giving it a well deserved rest after all its travel.

Happytamper,

I am glad you are enjoying your gauge. I am grateful I was able to spend time with Alchemist John using your machine. I learned more in those 3 hours than I could have learned just pulling blind for years! Learning that pulling too hard colapsed the puck, and that 5-7 bar makes a nice smooth, but unremarkable espresso. Feeling the flow increase without a major drop in pressure was interesting. I think there are many people pulling low pressure shots and not getting all they can from their machines. Thanks.

Les

WOW! I wonder if adding a little purge valve like the ones on tire pressure gauges might allow you to relieve the air pocket during pre-infusion and get a full shot.
For those of us without your lathe skills/patience, perhaps manufacturing a new piston shaft would be easier by taking an appropriate size and length of thick walled pipe and turning down to the proper dimensions. A set of threads on one end to match the existing (presumably metric) interface to the piston and we get to use npt on top so no custom adapter necessary there. That may also present an appropriate opportunity to change the interface with the lever (and fix your leak once and for all) by putting ears on the shaft rather than the through pin there now.

If I thought I could pull off the hole, I'd buy a spare shaft and go for it. However, I really don't have the confidence for that.

arri

Very slight leak in the modded La Pavoni has now been fixed with a bit of TIG welding. Leak was through the edge of the sleeve and was an easy fix with a tig welder and a bit of sanding.

I have been using the Modded La pavoni again for a while after switching to the Chrome europiccola for a while. Enjoy the brass la pavoni and needed a change of color. I am also using my new addition to the espresso collection, the Elektra microcasa. Great machine but I find it produces a thinner espresso. I hope to soon modify it so that I can help ramp up the infusion pressure by pushing up on the lever. This is possible on the Urania at my studio but not on the elektra. however the steam capacity of the Elektra is much better then the La pavonis. All seems to be well espresso wise and enjoy reading all the threads.

May have a new addition to the collection soon.

Good to see you alive and hopefully well Mitch! Have not seen you in the forums of late- Hope the summer was nice in Canada!

arriflex wrote:WOW! I wonder if adding a little purge valve like the ones on tire pressure gauges might allow you to relieve the air pocket during pre-infusion and get a full shot.
For those of us without your lathe skills/patience, perhaps manufacturing a new piston shaft would be easier by taking an appropriate size and length of thick walled pipe and turning down to the proper dimensions. A set of threads on one end to match the existing (presumably metric) interface to the piston and we get to use npt on top so no custom adapter necessary there. That may also present an appropriate opportunity to change the interface with the lever (and fix your leak once and for all) by putting ears on the shaft rather than the through pin there now.

If I thought I could pull off the hole, I'd buy a spare shaft and go for it. However, I really don't have the confidence for that.

arri

I never found the "appropriate" size of thick walled pipe. Nothing was ever thick enough. That had been my original plan. Drilling through turned out to be the only solution I could come up with. I am not sure what you mean by putting ears on the shaft to solve the leak problem.