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
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?
By "it" I assume you mean water, or pressure? Why would it care? I think I missed something along the way here. Rich
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
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>
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 $500 more in a = commercial machine with a rotary pump.
This is a multi-part message in MIME format. I'm really on shaky ground here, but maybe I remember (bad case of CRS, here) that the rotary pumps pump more of a constant volume than a constant pressure. That would mean a relatively constant rate of flow through the puck, with much less sensitivity to grind and tamp. But maybe it was something else. :-) -- Rick
This is a multi-part message in MIME format. I guess my questions are: In commercial machines, if it is not for quality of espresso purposes, why do they all use rotary pumps? Is it for the noise difference? Do they last longer? Less repairs? There must be some good reason why they use them. Joe RK Drum #9, Solis Maestro +, *$ Proteo Barista
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
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>
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.
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
This is a multi-part message in MIME format. No kidding. Would that be the message I quoted down there? -- Rick
This is a multi-part message in MIME format. Ah. "More than sufficient." Immediately forfeit all CSA points. -- Rick
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>
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 ***********************************************
Yes, it' reads 135psi just a tad over 9 bar Tom miKe mcKoffee wrote: <Snip>
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)
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;-)
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>
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
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>
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 ***********************************************
I 'knew' when I typed that, somehow it didn't sound right.
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 ***********************************************
<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
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
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>
That pump would look great with a jewel encrusted porta filter handle and a gold group head!! AlChemist John wrote: <Snip>
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/
yeah, had that happen to me too. AlChemist John wrote: <Snip>
Need? WHACK! -10,000 CSA points! :-) -- Rick