jpender wrote:Suppose the lever were in your kitchen connected via the internet to a machine a thousand miles away that responded precisely to the pressure and movements you made. Lever or not?

Nope. It's all got to be in my kitchen and serve coffee there.

Jim had it right. Is it a chicken or a dinosaur? What if it walks like a duck?

I think the Leva X is a lever. An almost science fiction version of one, and comparatively expensive to service with more parts that can go obsolete. I'd take one, sure, but I don't think anyone's giving them away.

If we're going to do philosophy, let's look at Wittgenstein's concept of "family resemblance". He observes that games may differ from one another in innumerable respects but they are all called games in virtue of traits that some share and others don't, analogous to what we see in members of a family.

Analogously, looking back over this thread, you can see contributors trying and failing to identify a trait common to all espresso machines that are said to be levers. As Wittgenstein says of games:

the result of this examination is: we see a complicated network
of similarities overlapping and criss-crossing: sometimes overall similarities, sometimes similarities of detail. (Philosophical Investigations, paragraph 66)

Could we not be satisfied with saying that the same of lever machines?

baldheadracing wrote:I think that you might be missing the historical references that provide the humour/sarcasm of the post.

But yes, <Jeremy Clarkson mode on>Some Say that a lever machine has no pump.<Jeremy Clarkson mode off> To answer your question, the group is filled by either gravity (open boiler), or boiler pressure (dipper), or line pressure (HX). Use of a pump to fill the group (in the machine, Jim) means that the machine is a hybrid of a pump and a lever. A mule is a hybrid of a donkey and a horse. A mule is not a horse, nor is it a donkey. A mule is its own thing, just as a "hybrid lever" is neither a lever machine nor a pump machine, but a combination of both.

The above paragraph is more humour. I happily call my Strega a lever machine.

What will you define the meticulous as? it fundamentally works as an open boiler lever, yes could theoretically use other technologies and achieve same end goal, but it doesn't so what dos it make it. It's clearly not a pump machine and the user have no direct control over the process as it's automated.

I think the progress we are seen in later years and merging of types really start calling for other definitions as we now seen several iterations of hybrids

What distinguishes a lever to me from other means of extraction is using a piston in a cylinder to compress a volume of water to espresso extraction pressure. Traditionally the piston is physically controlled by a leverage arm which identifies the machine as a lever but it's not the lever but the piston that defines a lever. It's not the lever but what it's attached to that makes it a lever. Replacing the lever controlled piston with a robotic piston still retains the piston extraction so it can be said it's a lever without the lever control.

That's one way to make a less ambiguous definition. If it has a piston it's a lever. Period. It's like saying a person is male if they have a Y chromosome: even if they also have three X chromosomes; or complete androgen insensitivity and all of the external characteristics of a female; or strongly feel like a female despite genetic and physical characteristics.

In other words, it's a simple definition but ultimately doesn't solve the question satisfactorily. You can have a pump driven machine that utilizes a piston. How is that anything like a lever? Does it have to be a fixed volume that is pumped with a single stroke of the piston? Then no Fellini moves are possible with levers.

I agree with Matt, there is no way to define it. In some cases it obviously is a lever and in others it obviously isn't. But there are going to be machines where it's not cut and dried and that's okay.

Right, but I think both you and mrgnomer are correct. That was the point I was trying to make in the penultimate paragraph of my earlier post.

I can design a lever machine without a piston. So how can that jive with the definition of piston = lever?


You could imagine a kind of Turing Test for levers. You have a lever sticking out of a machine in a plain case. You can't see the internals. You pull a shot. You can feel some feedback. Was it a lever or a simulation? Does it matter what's inside?

This thread is making want to find a massive gear pump and slap some acrylic and a lever on the side.
It might take a minute to warm up, but but the stability will be incredible.

However the problem is just as one can design a lever without a piston mechanism, we can also have a piston driven machine that doesn't use a lever at all. Could the answer to this taxonomic question be as simple as asking- if it has a lever acting on its extraction, it's a lever machine?

malling wrote:What will you define the meticulous as? it fundamentally works as an open boiler lever, yes could theoretically use other technologies and achieve same end goal, but it doesn't so what dos it make it. It's clearly not a pump machine and the user have no direct control over the process as it's automated.

I think the progress we are seen in later years and merging of types really start calling for other definitions as we now seen several iterations of hybrids

I haven't seen one nor looked into the machine with any interest, but at first glance it looks like it uses a single stroke linear pump.