Ponte Vecchio Lusso piston removal tool - Page 3

A haven dedicated to manual espresso machine aficionados.
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sorrentinacoffee
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#21: Post by sorrentinacoffee »

because printing one is easier? and possibly cheaper? and just as effective- though I still want to hear about the seal guide...

sprint jinx (original poster)
Posts: 220
Joined: 13 years ago

#22: Post by sprint jinx (original poster) »

I was unaware of the seal guide issue, so it was not included in my internal design brief. I said that I was open to revisions and tweaks, your idea of the guide seems more than a nice thing to have.

Maybe I get working on version 2.0, but I am overseas for a week. What I would have to know would be the external diameters of both top and bottom of the V.

thank you-

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sorrentinacoffee
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#23: Post by sorrentinacoffee »

you want to know the diameters of the V seals? Confused... I don't have the tool at the moment to measure the seal giude ring- but basically it is the same internal diameter as the piston chamber- with the top of the guide 'stepped' so it mates perfectly with the bottom of the cylinder. I am not sure if it would work- but possibly you could do away with the guide by dimply having the cavity inside the PF tool part being the same diameter as the piston chamber.

You can see the guide part here:

How to Change Lusso/Export Seals: The Ponte Vecchio Way!

sprint jinx (original poster)
Posts: 220
Joined: 13 years ago

#24: Post by sprint jinx (original poster) »

Hold on - wait for version 2.0

I tested the tool this morning. Here's what happened. I popped off the screen without issue. I borrowed a small plastic plug cap to cover the bolt's end face, and mounted the tool into the grouphead. The handle rotates further with the screen removed, but it is still a snug fit. I began to use a socket wrench to tighten the head of the bolt, and yes, a normal sized socket tool fits between the tray and the group for this application. When the plastic plug met the face of the piston, the captured nut began to slide towards the bolt's head, negating any progress on lifting the piston.
So, lessons learned:
The nut at the base needs to be more secure, or immovable.
Even better would be to adjust the design of the tool so that the nut is captured in the base of the basket, rather than outboard at the base of the PF cup.

I prefer to fix the design rather than chase after the current model. So, soon I will get into the cad file and make version 2.0. That should fix the issue from happening again.

I apologize for the mistake, perhaps there exists a way to modify the current tool to make it work, if you have plans to use version 1.0.

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spressomon
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#25: Post by spressomon »

Thinking a metal threaded insert might be more suitable. Something akin to these: http://www.mcmaster.com/#standard-threa ... ts/=xrz430

For whatever reason MMC links don't take you to the actual part page...but rather the section page. Thinking #92394A030 style...or one of the variants.

EDIT: sprintjinx's v2.0 appears to solve the bolt/nut issue! Disregard the above.
No Espresso = Depresso

sprint jinx (original poster)
Posts: 220
Joined: 13 years ago

#26: Post by sprint jinx (original poster) »

Version 2.0 is now uploaded on the thingiverse link above.

The new design has a hollow boss on both sides of the pf wall. So a nut can be put inside the basket as well as outside, with an obvious through hole for the bolt.
The head of the bolt is a 17mm socket.

My plan is to print one out and test it for strength. Stay tuned for an update after printing and testing.

Update -
My part came out of the printer this morning and into the group it went. I used some scrap paper as the bolt face cover and torqued the head until it met up with the piston. From there, the distance needed to see the lever handle loosen up is not alot. The tool took the pressure of the spring just fine, I reached the point where I could have removed the clips on the pin, but since the gaskets are fine, I stopped there, and released the spring, to its normal state.
So, the tool works, but I will add that if your 3d print is not robust in terms of material strength, well, all bets are off.
Let me know if anyone needs more assistance in this matter.

jinx

sprint jinx (original poster)
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#27: Post by sprint jinx (original poster) »

Well, here's an update to this project.
One of the two groups on my PVL is acting up, pulling the lever down on the left group causes an initial purge of water to come from the cylinder, prior to the opening of the hole that feeds from the boiler. My guess is that one of the seals on the piston has worn to the point that water is making its way to the basket.
I took the previously made piston removal tool and managed to remove the piston successfully, although the spring popped the piston out at the removal of the tool.
The seals look ok, not perfect, and so I am ordering more for a replacement of all of them on both pistons.
In the meantime, I can use the right hand group to make espresso, as long as I put the piston back in to the left group. Upon offering up the piston to the group, I noticed that the piston face bottoms out on the inside of the tool's cup, and does not allow the tool to be fitted into the group like a normal portafilter would. So, this called for version 3 to be made, this iteration changes the cup depth to be deep enough to accept the piston as it sits below the cylinder. I made the changes to the CAD file, and printed another prototype overnight. It fits, and now works better than ever.


In review- there is a new version up on thingiverse, it has a deeper and works better. It does not break, IF it is made of abs with a solid infill.
I'll be getting the new seals and swapping them in asap, this should be straightforward by this point.

thanks-

sprint jinx (original poster)
Posts: 220
Joined: 13 years ago

#28: Post by sprint jinx (original poster) »

Another update:
I ordered new seals for my Lusso and they came in, so I set about doing the work. I only swapped one group of the two on my lusso.
Because the new seals are ever so slightly larger, the middle one is difficult to insert into the cylinder. So, I measured the critical dimensions and printed a short open cuff that is tapered so it compresses the middle seal. I was able to offer up the piston, but the length of the spring pushes it right back out. I noticed that the upper pin hole becomes visible with the spring compressed with my hand force, so I was able to insert a straightened paper clip to hold the piston inside the cylinder. Then, I inserted the new PF tool and cranked the bolt into place, against the piston's face. Wala, job done.

I apologise for being lazy about updating the thread, and the files, and the parts on thingiverse. I will get to that, its just that I am a busy guy at work and home too. But, this tool is rock solid now.

Here's another way to skin this cat:
I have other hobbies that require expensive and unique tools. Members of my 'club' share the tools by mailing them around to those who need them, paying it forward with a gift inside the box.
I say we make just 1-5 of these tools and use them when we need them.
Mine is now up for 'sharing' if anyone is in need, just pm me.
We can keep track of the tool's whereabouts right here on this thread, or create a new one named PVL Tool.

many thanks- I am thrilled to see folks enthusiasm on this. Maybe its my way of giving back to a community that taught me so much when I was a newbie.

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sorrentinacoffee
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#29: Post by sorrentinacoffee »

awesome!

i actually post the factory tool around Australia for users here. But printing one of your new ones would be the way to go for a PV owner. Just two way post costs $20... It's good to service the piston BEFORE it fails. With the odd 3 monthly silicon lube- my bet is the seals would last much longer- and overall the extractions would be better and operation smoother. I am using my SAMA at the moment- the lever started feeling a little stiff- I popped open the group- lubed and now it is awesome again.

The last thing you could do if you can be bothered is print out the little disc for popping the shower screen back on... But that would just be the cherry on the top- it's not really needed- though it is good to use.

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sorrentinacoffee
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#30: Post by sorrentinacoffee »

you should contact Ponte Vecchio- they should print these and send one with every machine. They once emailed me and asked how users change the seals - as they had a customer who asked them!

They should send you some PV freebies for your efforts.