Author Topic: Good or great espresso machines? Let the arguing begin!  (Read 90058 times)

Tex

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #420 on: June 13, 2010, 04:00:26 PM »
Only drawback - no steam capability.

Not a deal killer for me at all if I found one for a steal...

My thing on this machine is that I don't have any desire for it to be a project machine. That is a pretty old design I'm guessing and might be a pain to source an o ring, seal, or something. The only way I'm getting something like that is if it's a screaming deal I can't pass up, otherwise I'll probably be looking at new for this purchase.  

I am only interested in learning about lever shots not any machine rebuilding, modding, or any of that stuff. I've already got one of those.  ;)

BTW: How's the Carezza coming along?

gratefulroast

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #421 on: June 13, 2010, 05:31:38 PM »
The cool kids don't do frou-frou; very uncool! 8)


I wanna be a rebel.

Pee-Wee the loner rebel
« Last Edit: June 13, 2010, 05:35:04 PM by gratefulroast »

Tex

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #422 on: June 13, 2010, 06:16:34 PM »
The cool kids don't do frou-frou; very uncool! 8)


I wanna be a rebel.

Pee-Wee the loner rebel


Oh, oh; I just found my opponent for my first match in the octagon. I can take him coach, put me in! :o :o


Pyment

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #423 on: June 15, 2010, 07:24:34 AM »
John,

I like to search more regionally for these type of things and this is helpful:

http://www.searchtempest.com/

Question on double boiler systems. I am unconvinced that a PID is needed on the steam boiler. I have also read comments by Jim at 1st Line where he seems to be saying that PID's aren't all that needed for the brew boiler. They get limed up and become more inaccurate as time goes on.

It sure would make it easier if I was just looking for a DB and no PID. Geeks are probabl dumping thos by the tone to get the new DB-PID units.

ButtWhiskers

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #424 on: June 15, 2010, 09:43:06 AM »
A PID-controlled unit will not have a quick enough response to have significant effects in a system with a large enough heat sink and boiler.  For something like a Gaggia it is absolutely indispensible, but for a larger double-boiler unit with a huge brass grouphead it becomes just another link to break.  If you have a huge, intermittent, throughput it might be useful, but I'd wager that even then we'd see far more variability introduced by minor loading and tamping inconsistencies than by the small heat perturbations seen with a robust semi-commercial double boiler unit.


Tex

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #425 on: June 15, 2010, 10:37:58 AM »
A PID-controlled unit will not have a quick enough response to have significant effects in a system with a large enough heat sink and boiler.  For something like a Gaggia it is absolutely indispensible, but for a larger double-boiler unit with a huge brass grouphead it becomes just another link to break.  If you have a huge, intermittent, throughput it might be useful, but I'd wager that even then we'd see far more variability introduced by minor loading and tamping inconsistencies than by the small heat perturbations seen with a robust semi-commercial double boiler unit.

A PID will not force a faster stabilizing of temps in a large commercial machine sized boiler; BW is 100% correct in that. But a PID should last a lot longer than a pstat or tstat, and the pstat's constant click clack is enough reason in itself to use a silent PID to control a boiler's temp.

The biggest problem I have with pstats is that when they fail it's a slow and at first an unnoticed failure. The temps start creeping up as the diaphragm leaks, and as a result the coffee starts getting bitter. A barista thinks his/her technique is at fault and starts tweaking their procedures and customers just think the coffee is crap and take their business elsewhere. So save your business, switch to PIDs. ;)


Tex

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #426 on: June 15, 2010, 10:47:55 AM »
John,

I like to search more regionally for these type of things and this is helpful:

http://www.searchtempest.com/

Question on double boiler systems. I am unconvinced that a PID is needed on the steam boiler. I have also read comments by Jim at 1st Line where he seems to be saying that PID's aren't all that needed for the brew boiler. They get limed up and become more inaccurate as time goes on.

It sure would make it easier if I was just looking for a DB and no PID. Geeks are probabl dumping thos by the tone to get the new DB-PID units.


Truism for SB/DU and double boiler machines: The larger the brew boiler the more stable the brew temps. A PID is necessary for small boiler machines to ensure that the inter-shot temp (beginning temp or recovery temp after pulling a previous shot) is where you want it. The PID has little or no effect on intra-shot temps (temp change as the shot is being pulled). That's where the larger boiler is invaluable - the larger the boiler the more constant the brew temp will be for a 2 oz pull.


Pyment

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #427 on: June 15, 2010, 12:18:39 PM »
would that be true with the Vibiemme Domobar Junior 2B? It has a 600ml boiler "controlled by bulb thermostat adjustable with 2 degree C increments"

http://www.1st-line.com/machines/comm_mod/esprmach/vibiemme/juniordb.html

The Double Domobar has a 1.4 liter boiler and uses a PID for the coffee boiler.

http://www.1st-line.com/machines/comm_mod/esprmach/vibiemme/vibiemme-manual-stainless-double-boiler-directconnect.htm

Tex

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #428 on: June 15, 2010, 03:54:06 PM »
would that be true with the Vibiemme Domobar Junior 2B? It has a 600ml boiler "controlled by bulb thermostat adjustable with 2 degree C increments"

http://www.1st-line.com/machines/comm_mod/esprmach/vibiemme/juniordb.html

The Double Domobar has a 1.4 liter boiler and uses a PID for the coffee boiler.

http://www.1st-line.com/machines/comm_mod/esprmach/vibiemme/vibiemme-manual-stainless-double-boiler-directconnect.htm


I'm not sure where the line is drawn as far as boiler sizes goes: I just figure bigger is better!

I wonder what the dead band is for the bulb tstat used in the VD Jr? That's the key to temp control; bimetallic tstats have huge (~30°F either way!) dead bands, which is why it's so difficult to manage temps. Pstats are better; IIRC the Siria is set to 3°F and a PID has no dead band to speak of.


GC7

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #429 on: June 15, 2010, 03:57:04 PM »
I would never buy a double boiler espresso machine for home use that was not PID controlled.  

The DD brew boiler of 1.4 liters is large for home use (the Gaggia for comparison is I believe 3 1/2 oz. (~0.1 liter) >:D and the La Spaz is 0.45 liter ) but still would benefit IMO from a PID.  Their main purpose aside from being more reliable/durable then a thermostat/pressurestat is the ability to tune the deadband temperature range to plus/minus about 1 degree (the wadlows I use in my lab are good to about 0.1 degree). A thermostat will range significantly higher and lower then your desired brew temperature so you will not know the actual brewing temperature rather a (larger then PID controlled) range around your desired temperature from shot to shot. With th money already being invested in a good machine why not make it both more reliable and accurate in temperture management?
« Last Edit: June 15, 2010, 04:33:32 PM by GC7 »

Tex

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #430 on: June 15, 2010, 05:41:31 PM »
Here's something Jim Gallt did; comparing the temp stability of a Rancilio Silvia with an OEM bimetalic tstat and a PID. Notice the swings above and below the target temp - that's what's known as dead-band, the swings in temp as the tstat opens & closes at its preset temp.


Offline peter

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #431 on: June 15, 2010, 08:12:18 PM »
If that red band was a neon green, it would look just like your avatar.
Quote of the Day; \"...yet you refuse to come to Me that you

Offline John F

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #432 on: June 15, 2010, 08:14:18 PM »
If that red band was a neon green, it would look just like your avatar.

Blahahahaha!

"At no point should you be in condition white unless you are in your bed sleeping with your doors locked."

Lee Morrison

Pyment

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #433 on: June 16, 2010, 07:26:30 AM »
I really am finding the Vibiemme Domobar Junior hard to resist.

There isn't an indication of how large the dead band is on the bulb thermostat.

I suppose an inquiry to 1st line is in order.

BoldJava

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Re: Good or great espresso machines? Let the arguing begin!
« Reply #434 on: June 16, 2010, 07:34:42 AM »
I really am finding the Vibiemme Domobar Junior hard to resist.



Dave, toss in a MACAP 4 (stepless) at $429 and you have a set-up that will hold you until Social Security should kick in.  Peddle the Rocky.  Peter and I both run the Macap should you wish to see/hear it in action (stepped though)  http://www.1st-line.com/machines/home_mod/macap/M4.htm

B|Java