I'm looking for a new machine that doesn't require plumbing, and the Vivaldi II Mini and Alex Duetto have captured my attention.

I noticed that the rotary pump in the Alex is located directly above the pump motor.

My only rotary pump machine developed a leaky seal after ~ 4 years of home use. I suspect it would have made a mess of the pump motor if it had been in the Alex. I've read posts by others saying rotary pumps are ultra reliable, don't worry about leaks, etc., but a quick search of HB brings up a few posts about leaking rotary pumps. So it does happen. Seems worrisome to me.

Anyone have a perspective on this? How rare are leaking seals in rotary pumps, and how likely is a leak to fry, er saute, the motor in an Alex?

Thanks,

Rick

Java Man wrote:Anyone have a perspective on this? How rare are leaking seals in rotary pumps, and how likely is a leak to fry, er saute, the motor in an Alex?

Cooking in a little water? I think it would be more of a braise.

As for your question, you are asking people to either engage in flights of speculation or survey the actual damage complaints (if any) online, which you can do just as easily yourself.

I tend to over analyze things, but that's what steered me away from the Duetto. A bearing failure will take out the electrical motor. But that is a fairly rare event. Asked Chris @ ChrisCoffee, and he agreed, but said basically if you're going to squeeze that much into that small a space, then your mounting choices are limited.

Regardless of Marshall's flippant response, I've wondered the same thing myself. I had seriously considered a GS/3, but lack of QC and numerous problems that seem to crop up has killed that for me. Looking at other 2xboilers brought me to your position.

Given that the Duetto is likely a wonderful machine, for me the location of the pump/motor killed that one for me and now I'm leaning quite heavily towards the VMB DD due to the relative "build safety".

Now, I need to justify the VBM DD over the Elektra A3 (the other woman, so to speak).

I doubt this sheds any light on your question, except to relate that you are not the only one uncomfortable with that build.

Cheers and good luck in your final choice.

Dave

Cramming everything you need for a double boiler into a kitchen-friendly size is a daunting task that is only accomplished by using every bit of available space. There is no way to avoid putting parts in close proximity to each other. This makes these machines more difficult to design, to assemble and to repair.

I have been told that the Dalla Corte Mini takes more time to assemble than its big commercial brothers, which is one of the reasons for its relatively high price.

That being said, there is a lot of owner experience with these machines, which I would put more stock in than speculation about what could or might happen because of a particular configuration.

Marshall wrote:I have been told that the Dalla Corte Mini takes more time to assemble than its big commercial brothers, which is one of the reasons for its relatively high price.

What does this have to do with the DC?

Marshall wrote:I wish people would stop comparing the output of machines with which they have zero experience.

hmmm

What does this have to do with the DC?

It's a double boiler. It's an example of the difficulty of configuring two boilers for home kitchen use and explains why critical parts in home machines tend to be in closer proximity than might be ideal.

As far as comparing the output of machines with which I have no experience, I'm fairly certain I did not do that. I did not even describe the output of a single machine.

As a point of reference, the double boiler Expobar Brewtus III-R mounts the pump horizontally. Marshall is right, there sure isn't much wiggle room:

Thanks for all your comments, including the flights of speculation that rotary pumps leak and water runs downhill.

Rick

And of course the BIIIR has the luxury of not needing space for a reservoir like the Duetto. Don't know if it would have been possible to mount the motor and pump horizontally and used a wider shallower reservoir with enough practical capacity. Regardless the vertical mounting would not be enough to deter me from Duetto. I mean, there are all kinds of ways a leak could happen and possibly fry the motor or other even more expensive electronics for that matter in most all espresso machines. Yet agree absolutely design layouts to minimize risk of potential expensive repairs is a good thing. Yet again the Alex Duetto is quite unique at its price point having internal rotary pump and reservoir or direct plumb option at the flip of a switch.

Java Man wrote:Thanks for all your comments, including the flights of speculation that rotary pumps leak and water runs downhill.

Actually there's no speculation at all; I've seen water run downhill many times.

Java Man wrote:
I noticed that the rotary pump in the Alex is located directly above the pump motor.

I asked the same question about the new Duetto II on the Vivaldi S1 forum:

http://www.s1cafe.com./viewtopic.php?f=13&t=1127

Have a look through the same forum on all the examples of rotary leaks. It's definitely something you need to routinely inspect for.

I personally love the vibe pumps. Simple, soft ramp-up, no leaks, no burn-out if you run it dry, and cheap to replace. Some people just love rotaries but personally I don't see the advantage except for the "wow" factor and cool noise.

Endo wrote:I personally love the vibe pumps . . . Some people just love rotaries . . .

Yes, and some people love machines with no pumps. Personally, I'd never go back to a vibe pump, have never had problems with rotary pumps -- save once when the pomace clogged the impeller, but that was in a winery not my kitchen -- and it's not that big of a deal anyhow . . . .

Double boiler machines? HX models? They all work -- I've never seen any huge advantage of one over the other. You want "easy"? Get a super auto! After all, You pays your money and you takes your choice!

One other point of note; the electronics on the Duetto are on top of the case and Chris stated "The first you will probably notice is that we are having Izzo insulate the steam boiler and add additional vents both top and bottom to promote cooling inside the machine. This will help to prolong the life of the electronic components inside the machine."

I had preordered a Duetto but after a little more dd I ordered the Mini Vivaldi II. I really liked the Duetto but it's somewhat of a new design, which most likely will experience -0- problems, however, the Vivaldi has been out in the field for a number of years now.

I don't think you would go wrong with either machine but it's my money and I took my choice.

Not that hard to relocate a rotary pump to be remote (ie outside the case). Has the benefits of also reducing rattle vibration and making pressure adjustments trivial.

If I recall correctly, the pump mounting was changed from regular Alex to Duetto. The point was to reduce vibration and noise.

i'm no machinist, but it seems like it would be a pretty straightforward task to just put a waterproof "shell" between the pump and the motor...like an inverted coffee can with a hole cut out of the bottom with a rubber seal that would be made water tight when the pump and motor sandwiched it together (of course in production the coffee can would be the highest grade stainless machined to absolute perfection, with padding to avoid adding any more vibration/noise to the machine

if it did leak, water would flow over the stainless umbrella and into the case where it would cause less damage.....

or just move it outside the case...

From the couple of machines I have looked at and rebuilt I can say that Procon pumps can and will leak. But it seems they only do it if they are left idle. If they get regular use they seem to last a long time, but if stored improperly they will die with about a year on idle. So if you are looking at a used machine the motor up pump down configuration would seem to be the least damaging to the motors bearings. But even with that you can still get 'bloom' of strange minerals into the shaft/pump interface. But that nice air gap leaves you room to clean out with out damage.

Hope that makes sense.

-Cecil

malachi wrote:or just move it outside the case...

Chris, that would not work in most houses.

Me: "Honey, could you please empty the cookware out of that cabinet so I can install my espresso machine pump."

Wife: "I'll show you where to put that espresso machine pump!"

Back to the original issue. Is that a bad design idea?