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Topic: [coffee] +Rotary vs. vibe (36 msgs / 849 lines)
1) From: Rick Farris
This is a multi-part message in MIME format.
If that were true, then you should be able to pull the AC power plug out
of the wall half-way through the shot and have it continue to the end
normally.  Give it a try and report back.  :-)
 
-- Rick

2) From: alfred
This is a multi-part message in MIME format.
MessageOK: If the pump supplies correct  pressure, properly controlled, =
how does the coffee in the PF know whether it comes from a rotary or =
vibe pump?

3) From: Rich Adams
By "it" I assume you mean water, or pressure?
Why would it care?
I think I missed something along the way here.
Rich

4) From: alfred
Pressure, exactly!

5) From: Rick Farris
This is a multi-part message in MIME format.
Bad premise!   I can't remember all the details from the last time I saw
this go around, but the rotary pump provides a constant ...  Nope, I
can't remember the details.
 
-- Rick

6) From: Greg Scace
That is the salient question.  IMO if the pressure building profile, 
pressure control scheme are equivalent, then rotary and vibe pump 
performance should be pretty damn near to equal.  some folks make a fuss 
about pressure fluctuations due to 60hz. cycling of the diaphragm, but they 
forget that rotary pumps have pressure flutter as well due to the vanes 
passing by the pump outlet.  As near as I can tell, properly regulated vibe 
pumps perform the same as rotary pumps, but they are noisier for sure.
-Greg
At 02:15 PM 1/8/2004 -0800, you wrote:
<Snip>

7) From: alfred
This is a multi-part message in MIME format.
This is exactly the point I am trying to make:
    Scenario: In order to pull a great shot, due to the fluctuations in =
pressure with a vibe pump, I am going to invest $500 more in a =
commercial machine with a rotary pump.

8) From: Rick Farris
This is a multi-part message in MIME format.
I'm really on shaky ground here, but maybe I remember (bad case of CRS,
here) that the rotary pumps pump more of a constant volume than a
constant pressure.  That would mean a relatively constant rate of flow
through the puck, with much less sensitivity to grind and tamp.  But
maybe it was something else.  :-)
 
-- Rick

9) From: Joseph A. Feliciani
This is a multi-part message in MIME format.
I guess my questions are:
 
In commercial machines, if it is not for quality of espresso purposes,
why do they all use rotary pumps? Is it for the noise difference? Do
they last longer? Less repairs?
 
There must be some good reason why they use them.
 
Joe
RK Drum #9, Solis Maestro +, *$ Proteo Barista

10) From: alfred
This is a multi-part message in MIME format.
MessageRick: This comes from Greg 
That is the salient question.  IMO if the pressure building profile, =
pressure control scheme are equivalent, then rotary and vibe pump =
performance should be pretty damn near to equal.  some folks make a fuss =
about pressure fluctuations due to 60hz. cycling of the diaphragm, but =
they forget that rotary pumps have pressure flutter as well due to the =
vanes passing by the pump outlet.  As near as I can tell, properly =
regulated vibe pumps perform the same as rotary pumps, but they are =
noisier for sure.  
-Greg

11) From: Greg Scace
At 02:51 PM 1/8/2004 -0800, you wrote:
<Snip>
As near as I can tell, most vibe pump installations are unregulated.  I 
think exceptions are the e61 Isomacs and the Valentino.  I stuck a pressure 
regulator inside my Silvia and that changed things substantially in the 
consistency department.  Ther's a really simple silvia mod for turning the 
over-pressure relief valve into a pressure regulator.  Search google for 
it.  I think that supposed issue with vibe pump pressure flutter is so much 
bullfeces, however the lack of proper pressure regulation is a lame scene 
which machine manufacturers should fix in their machines.  They're just too 
damn cheap I guess.
<Snip>

12) From: alfred
This is a multi-part message in MIME format.
MessageAccording to the people here at Aarabee Coffee the only reason =
for the use of the rotary instead of the vibe is the degree of usage and =
the ultimate necessity to change out the pump in a commercial setting. =
For home usage or even light commercial, the vibe is more than =
sufficient.

13) From: paul
On Thu, Jan 08, 2004 at 02:59:20PM -0800, Joseph A. Feliciani wrote:
<Snip>
My guess would be: volume.
A commercial machine would be designed so that all of the groups + 
steam + water could be run at the same time(1). I suspect getting
a vibe pump to handle the load would be either difficult or expensive.
Cheers
Paul Haddon
Sydney, Aus
(1) We'll leave discussions on temperature stability for another 
thread

14) From: Rick Farris
This is a multi-part message in MIME format.
No kidding.  Would that be the message I quoted down there?
 
-- Rick

15) From: Rick Farris
This is a multi-part message in MIME format.
Ah.  "More than sufficient."  Immediately forfeit all CSA points.
 
-- Rick

16) From: Tom Murray
I did the pressure mod on my recently sold Silvia.
I measured the pressure before (165psi) after the mod(135psi) Thanks greg.
The pressure on a rotary pump will be consistent. through out the pour.
Tom
Greg Scace wrote:
<Snip>

17) From: miKe mcKoffee

18) From: Ed Needham
You'll get a lot more with a commercial machine than a rotary pump, but I'm
not sure everyone needs a commercial machine.
***********************************************
Ed Needham
To Absurdity and Beyond!
homeroaster ... d.o.t ... com
***********************************************

19) From: Tom Murray
Yes, it' reads 135psi just a tad over 9 bar
Tom
miKe mcKoffee wrote:
<Snip>

20) From: miKe mcKoffee

21) From: Tom Murray
Here is a review by Ken Fox. He is one of the few owners that has owned 
both versions of the same machine. A Cimbali Jr
His opinion is that the rotary pump is better.
If I am not mistaken Jim Schulman was at ken's house and compared both 
machines. Please correct me if I am wrong.http://www.coffeegeek.com/reviews/commercial/lacimbalijunior/champignonTom( who is still with out power)

22) From: miKe mcKoffee

23) From: miKe mcKoffee
Good information, thanks. Does it greatly reduce the confusion factor in
deciding upgrade path? If I only knew... I'd started leaning towards a
Giotto, in part it's under the cabinet clearance and great looks, but not so
sure it still wouldn't be a compromise. Back to a rotary plumbed unit being
higher priority than convenient quick counter placement. Dual boiler (Reneka
or) or HX another matter. HX likely...
Since you got me looking, and of course checking eBay, here's a La Cimbali
up for auction that might be a wee bit much for most homes...http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item%86846464&categoryS187MM;-)

24) From: Jeffrey A. Bertoia
Although I did not own both machines I pulled shots on both of them.  
And decided after a lot of thought
on the vibe for a couple of reasons...
After speaking to several of the owners of both machines (generally 
light commercial) and the
service guys the vibe jr was more trouble free.  Not necessarily because 
of pump problems.
One of the major differences in the vibe vs rotary debate is 
preinfusion.  In order to implement
preinfusion on a rotary pump control must be active.  In other words the 
pump must be stopped
after wetting the puck.  Since the vibe builds pressure up slowly the 
preinfusion cycle is natural.
This means that the rotary has to have extra control and this was the 
area where the rotary jr
failed more often.
As far as coffee quality I disagree with the review.  Head to head with 
the same grind and both
machines extracting a double in about 25 seconds the vibe produced a 
sweeter shot.  If  I
grind too fine I kill it at 30 seconds and drink a short one so I don't 
know about the rotary
producing a better shot under those conditions.
As with all rotaries, plumbing it in is a requirement, and that limited 
my flexability.  I live on
a lake and in the summer during parties we frequently take jr out on to 
the deck and serve
out there.  (I have been looking for an inverter for the boat :->)  This 
is not a _huge_ issue
to us but it is definately nice.
All in all, after evaluating it,  I decided that the vibe jr was the 
best buy for _me_.  I do not
regret that decision.
BTW - I have had it for between almost 3 years.
jeff
Tom Murray wrote:
<Snip>

25) From: Dan Bollinger
This is a multi-part message in MIME format.
MessageJoe,  Just so you know, 'rotary' is an abbreviation. In our =
context it is short for 'rotary vane carbonator pump.' There are a =
number of reasons rotarys are used in commercial applications. First, =
you'd need 3 vibes for a 3 grouphead machine, but only one rotary. =
Second, the rotary pumps that are used were already in food service and =
had NSF approval. They are the same pumps used to dispense soda. Also, =
they last for years. We have one a work and it has run 10 hours a day =
every day for the last 7 years. Finally, they have excess capacity, =
making tuning the espresso machine easier. 
  I guess my questions are:
  In commercial machines, if it is not for quality of espresso purposes, =
why do they all use rotary pumps? Is it for the noise difference? Do =
they last longer? Less repairs?
  There must be some good reason why they use them.
  Joe
  RK Drum #9, Solis Maestro +, *$ Proteo Barista

26) From: Tom Murray
Ed my needs and wants are the same when it comes to espresso. :)
I had a PID'd and pressure mod Silvia and still was not happy with what 
I was getting. Of course it's not really fair to
compare my $six hundred silvia against Stumptowns Mistrals 
http://www.keesvanderwesten.com/)So I decided I needed and wanted a Lyra. When I use Stumptowns beans, I 
find I can get the same consistence
and taste more so with the Lyra than I could the hoped up Silvia.
Tom
Ed Needham wrote:
<Snip>

27) From: Ed Needham
The rotary Procon was already in a lot of shops as a carbonator for soft
drinks.  It was easy to get replacements and basically an on the shelf
workhorse.  I wouldn't want to take the Procon out of my machine and replace
it with a Ukla vibe.  Even if it didn't change the shots a bit, I think the
consistency, reliability and durability are issues I would not want to give
up.  I don't have much to base that on, but my Procon weighs probably 15
pounds and I'd guess the Ukla is around 6 ounces or so?  Still not a good
argument though.
***********************************************
Ed Needham
To Absurdity and Beyond!
homeroaster ... d.o.t ... com
***********************************************

28) From: Ed Needham
I 'knew' when I typed that, somehow it didn't sound right.

29) From: Ed Needham
I had a Gaggia Espresso (high end entry level machine) before I got my La
Pavoni PUB, single group espresso machine.  The Gaggia could pull wonderful
shots, but it was really on the edge of it's ability and capacity.  The La
Pav can pull good shots all day without breaking a sweat, and without
fiddling with 'temp surfing' or anything more than clearing the heat
exchanger if it's been sitting for a while.  It sounds like a 'real' espresso
machine, feels like one and works day in and day out.  The WOW factor counts
for something.
The Gaggia is in a box in my basement.  Took it to work last year to pull
shots for a couple of days and it performed like a champ, except for a
dripping grouphead.  I guess the valve corroded while in  storage.  Gotta fix
that.
***********************************************
Ed Needham
To Absurdity and Beyond!
homeroaster ... d.o.t ... com
***********************************************

30) From: Gene Smith
<Snip>
And a thoroughly trippy link from the above URL:http://www.espressomadeinitaly.com/sito_inglese/_index.htmGo and look at the lovely machines in the museum.
Gene Smith
riding the wild learning curve in Houston

31) From: Joseph A. Feliciani
This is a multi-part message in MIME format.
MessageThanks, Dan, I knew there had to be a reason!
Joe
RK Drum #9, Solis Maestro Plus, *$ Proteo Barista

32) From: AlChemist John
This is scary when I start understanding this kind of discussion due to my 
Chemistry work....vaguely wondering why I have not heard of any dual 
sapphire piston rod reciprocating pumps like I use on my HPLC?  Probably 
lack of volume I guess...
Sometime around 14:50 1/8/2004, Greg Scace typed:
<Snip>

33) From: Ben Treichel
That pump would look great with a jewel encrusted porta filter handle 
and a gold group head!!
AlChemist John wrote:
<Snip>

34) From: AlChemist John
I know what you mean, but was so disappointing seeming my first sapphire or 
ruby piston.  For this kind of work, they are clear.  Never really 
understood that.
Sometime around 05:59 1/9/2004, Ben Treichel typed:
<Snip>
--
John Nanci 
AlChemist at large
Zen Roasting and Blending by Gestalthttp://www.dreamsandbones.net/blog/

35) From: Ben Treichel
yeah, had that happen to me too.
AlChemist John wrote:
<Snip>

36) From: Rick Farris
Need?  WHACK!  -10,000 CSA points!  :-)
-- Rick


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