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Date: 23 Oct 2006 05:26:57
From: Robert Harmon
Subject: Presisia PID, is it too good to be true?
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I was looking at some PID's I was told about in another post & came across
what seems like an interesting machine.
http://auberins.com/index.php?main_page=product_info&cPath=6&products_id=20
Precisia Espresso Machine w/PID - $185?
There is a speculative discussion about it on CoffeeGeek, but no ones seems
to have actually had their hands on one. I was just curious if anyone here
has actually seen one & used it?
http://www.coffeegeek.com/forums/espresso/machines/260258
--
Robert (Watch out for Chinese knock offs, they're getting better & cheaper.)
Harmon
http://tinyurl.com/pou2y
http://tinyurl.com/psfob
http://tinyurl.com/fkd6r
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Date: 23 Oct 2006 18:48:18
From: Robert Harmon
Subject: Reply from Presisia about sub-$200 PID equipped machine.
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I requested info from http://auberins.com/ about parts for a PID conversion
& their PID equipped espresso machine price under $200 & here is the reply.
----------------------------------------------------------------------
>
> I'm converting a professional espresso machine that uses a Sirai pressure
> stat to use your Universal PID. I'll be ordering a temp sensor & SSR from
> you. I want to insert the sensor into the boiler for accuracy. Which SSR &
> sensor do you recommend for my use?
The 25 A SSR is the most common one used. It has a plastic cover (or
protected terminal). With 120V AC line volatage, the 25 A SSR is sufficient
to handle a 3000 Watt heater. For the sensor, there are many different
option and different opinions in the community. Here is what I think. You
will get a more accurate temperature if the sensor is in the water. However,
if the sensor it too close to the heater in the water, it will take a long
time to heat up the system unless the water is circulated. Putting the
sensor on the metal wall will speed up the heating, but water can be hoter
than the metal. However, if you let it sit for a few seconds (or a minutes
or so), I believe the temperature will become uniform. My personal choice
will be the Pt100 with washer mount. Themocouple could have a few degree
drift. The thermocouple cold junction compensation of most controller are
not very precise. If the controller working enviroment does not have a
stable temperature, there could be a error. The RTD (pt100) sensor does not
have this problem.
>
> Do your SSR's have plastic covers?
>
> Finally, I'm VERY curious about the espresso machine you sell. Could you
> provide me with more specs, such as boiler size & material, portafilter
> type (pressurized or not), size & material, construction materials
> (plastic, steel, S/S, or cardboard)?
This machine has very similar construction (material and size) as the
Starbucks' Barista and DeLonghi's EC701. It is designed for the same ket
..... people don't have a expensive grinder and skill of making espresso and
cappuccino. It produce much more consistent espresso than any machine in
that class. I understand that most "coffee nuts" are critical about the
pressurized portafilter. We compared the quality of the coffee with a PID
modified Silvia but could not find significant different. In terms of
boiler size, we measure the temperature change at the surface of coffee
during a double shot. It varies less than 2 degree after reach the peak
temperature. The temperature change before reach the peak will depending on
the pre-warming condition of the coffee and system. This is also very
simialr to the Silvia performce measured with Greg Scace device.
> --
> Thanks,
> Robert
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Date: 23 Oct 2006 16:57:20
From: Jack Denver
Subject: Re: Reply from Presisia about sub-$200 PID equipped machine.
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& here is the reply.
> ----------------------------------------------------------------------
> The 25 A SSR is the most common one used. It has a plastic cover (or
> protected terminal). With 120V AC line volatage, the 25 A SSR is
> sufficient to handle a 3000 Watt heater.
Yes but if you have a smaller element then you can get a smaller SSR. A few
extra amps cushion doesn't hurt but you don't want to overpay for a vastly
oversized SSR.
Is your machine 220V and is your existing Sirai set up to switch both lines?
For the sensor, there are many different
> option and different opinions in the community. Here is what I think. You
> will get a more accurate temperature if the sensor is in the water.
> However, if the sensor it too close to the heater in the water, it will
> take a long time to heat up the system unless the water is circulated.
> Putting the sensor on the metal wall will speed up the heating, but water
> can be hoter than the metal. However, if you let it sit for a few seconds
> (or a minutes or so), I believe the temperature will become uniform. My
> personal choice will be the Pt100 with washer mount. Themocouple could
> have a few degree drift. The thermocouple cold junction compensation of
> most controller are not very precise. If the controller working enviroment
> does not have a stable temperature, there could be a error. The RTD
> (pt100) sensor does not have this problem.
It sounds like this guy's experience is with small single boilers (e.g.
Silvia) that are completely water filled. For a large steam boiler the most
responsive spot will be in the steam, not in the water or on the metal.
Most people here prefer thermocouple to RTD. Presumably wherever you mount
the controller (either inside the machine or I keep mine in a project box on
my cup tray) will have a fairly constant temperature, at least after the
machine comes up to temp.
>>
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Date: 24 Oct 2006 00:55:20
From: Andy Schecter
Subject: Re: Reply from Presisia about sub-$200 PID equipped machine.
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Jack Denver wrote:
> For a large steam boiler the most
> responsive spot will be in the steam, not in the water
Why do you think there's a significant difference between the steam and water
temps?
> Most people here prefer thermocouple to RTD.
Because of cost and familiarity. If you're willing to pay for an RTD, you'll
get better accuracy.
--
-Andy S.
http://www.flickr.com/photos/andy_s/sets/
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Date: 23 Oct 2006 23:36:13
From: Jack Denver
Subject: Re: Reply from Presisia about sub-$200 PID equipped machine.
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I realize that inside a pressurized vessel the water temp is exactly the
same as the steam temp under stable conditions. But I'm guessing that there
is a lag when there is a pressure drop (e.g. you open the steam valve) as
it would take some time for some of the liquid water in the vessel to
vaporize and cool the rest until the equilibrium between steam and water
temp was again reached. Take the extreme case where you chop a hole in the
boiler with an ax - the steam temp would drop instantly but the water would
continue to boil for a while until it was no longer above boiling - the hot
metal of the boiler would continue to add heat until it too cooled below
boiling. I have no idea what the magnitude of this lag is under normal
conditions (steam valve opening) or whether it is significant or only
microseconds.
"Andy Schecter" <schecter@remove.me.rochester.rr.com > wrote in message
news:Yvd%g.9307$484.34@twister.nyroc.rr.com...
> Jack Denver wrote:
> > For a large steam boiler the most
>> responsive spot will be in the steam, not in the water
>
> Why do you think there's a significant difference between the steam and
> water temps?
>
>> Most people here prefer thermocouple to RTD.
>
> Because of cost and familiarity. If you're willing to pay for an RTD,
> you'll get better accuracy.
>
>
>
> --
>
>
> -Andy S.
>
> http://www.flickr.com/photos/andy_s/sets/
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Date: 24 Oct 2006 11:56:14
From: Johnny
Subject: Re: Reply from Presisia about sub-$200 PID equipped machine.
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"Jack Denver" <nunuvyer@netscape.net > wrote in message
news:CLCdnQRga62xF6DYnZ2dnUVZ_sSdnZ2d@comcast.com...
<snip/ >
> I realize that inside a pressurized vessel the water temp is exactly the
> same as the steam temp under stable conditions. But I'm guessing that
there
> is a lag when there is a pressure drop (e.g. you open the steam valve) as
> it would take some time for some of the liquid water in the vessel to
> vaporize and cool the rest until the equilibrium between steam and water
> temp was again reached. Take the extreme case where you chop a hole in the
> boiler with an ax - the steam temp would drop instantly but the water
would
> continue to boil for a while until it was no longer above boiling - the
hot
> metal of the boiler would continue to add heat until it too cooled below
> boiling. I have no idea what the magnitude of this lag is under normal
> conditions (steam valve opening) or whether it is significant or only
> microseconds.
>
>
That's a clever approach Jack. Some day I'll have to test it out, not
doubting you, just like to watch it happen.
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Date: 24 Oct 2006 10:00:19
From: Andy Schecter
Subject: Re: Reply from Presisia about sub-$200 PID equipped machine.
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Jack Denver wrote:
> inside a pressurized vessel the water temp is exactly the
> same as the steam temp under stable conditions. But I'm guessing that there
> is a lag when there is a pressure drop (e.g. you open the steam valve) as
> it would take some time for some of the liquid water in the vessel to
> vaporize and cool the rest until the equilibrium between steam and water
> temp was again reached.
There is a lag, but is it significant compared to the response time of the
thermocouple in its sheath? I doubt it, but I don't have data.
--
-Andy S.
http://www.flickr.com/photos/andy_s/sets/
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Date: 24 Oct 2006 10:32:10
From: Coffee for Connoisseurs
Subject: Re: Reply from Presisia about sub-$200 PID equipped machine.
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May I suggest that getting excited (in a positive OR negative fashion) over
this machine may be an overreaction? If it's still got the same SS boiler as
the one I bought (see http://www.coffeeco.com.au/newsletter/june2004.html )
the influx of cold water during the shot, into the teensy boiler, will
override any possible benefit the PID may bring.
--
Alan
alanfrew@coffeeco.com.au
www.coffeeco.com.au
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Date: 24 Oct 2006 16:32:47
From: jim schulman
Subject: Re: Reply from Presisia about sub-$200 PID equipped machine.
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On Tue, 24 Oct 2006 10:32:10 GMT, "Coffee for Connoisseurs"
<alanfrew@coffeeco.com.au > wrote:
>May I suggest that getting excited (in a positive OR negative fashion) over
>this machine may be an overreaction? If it's still got the same SS boiler as
>the one I bought (see http://www.coffeeco.com.au/newsletter/june2004.html )
>the influx of cold water during the shot, into the teensy boiler, will
>override any possible benefit the PID may bring.
Look on the bright side, you'll get **repeatably** crappy shots at any
starting temperature you chose.
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Date: 24 Oct 2006 14:07:53
From: Jack Denver
Subject: Re: Reply from Presisia about sub-$200 PID equipped machine.
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I agree that the boiler could be bigger but I had a Saeco with a very
similar hockey puck sized boiler and it actually kept up fairly well over
the course of a shot, especially if you gave the heating element a head
start with the steam switch. Think of it as a oversized thermoblock where a
lot of the heating is done "on the fly". I dunno where this one has its temp
sensor but they claim that the reading remains stable during the shot.
"Coffee for Connoisseurs" <alanfrew@coffeeco.com.au > wrote in message
news:KYl%g.52242$rP1.37844@news-server.bigpond.net.au...
> May I suggest that getting excited (in a positive OR negative fashion)
> over this machine may be an overreaction? If it's still got the same SS
> boiler as the one I bought (see
> http://www.coffeeco.com.au/newsletter/june2004.html ) the influx of cold
> water during the shot, into the teensy boiler, will override any possible
> benefit the PID may bring.
>
>
> --
> Alan
>
> alanfrew@coffeeco.com.au
> www.coffeeco.com.au
>
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Date: 23 Oct 2006 21:52:53
From: Robert Harmon
Subject: Re: Reply from Presisia about sub-$200 PID equipped machine.
|
"Jack Denver" <nunuvyer@netscape.net > wrote in
news:yJOdnbgh1_cosaDYnZ2dnUVZ_qednZ2d@comcast.com:
> & here is the reply.
>> ----------------------------------------------------------------------
>> The 25 A SSR is the most common one used. It has a plastic cover (or
>> protected terminal). With 120V AC line volatage, the 25 A SSR is
>> sufficient to handle a 3000 Watt heater.
>
> Yes but if you have a smaller element then you can get a smaller SSR.
> A few extra amps cushion doesn't hurt but you don't want to overpay
> for a vastly oversized SSR.
>
> Is your machine 220V and is your existing Sirai set up to switch both
> lines?
>
> For the sensor, there are many different
>> option and different opinions in the community. Here is what I think.
>> You will get a more accurate temperature if the sensor is in the
>> water. However, if the sensor it too close to the heater in the
>> water, it will take a long time to heat up the system unless the
>> water is circulated. Putting the sensor on the metal wall will speed
>> up the heating, but water can be hoter than the metal. However, if
>> you let it sit for a few seconds (or a minutes or so), I believe the
>> temperature will become uniform. My personal choice will be the Pt100
>> with washer mount. Themocouple could have a few degree drift. The
>> thermocouple cold junction compensation of most controller are not
>> very precise. If the controller working enviroment does not have a
>> stable temperature, there could be a error. The RTD (pt100) sensor
>> does not have this problem.
>
>
> It sounds like this guy's experience is with small single boilers
> (e.g. Silvia) that are completely water filled. For a large steam
> boiler the most responsive spot will be in the steam, not in the water
> or on the metal. Most people here prefer thermocouple to RTD.
> Presumably wherever you mount the controller (either inside the
> machine or I keep mine in a project box on my cup tray) will have a
> fairly constant temperature, at least after the machine comes up to
> temp.
>
>
>>>
>
>
>
The Bunn is a 120v AC & the Sirai is configured to use only one set of
the three contacts. So it seems that you're saying that to get the most
responsive reading from the TC it would be better to mount it inside the
boiler where the steam is, namely the to inch or so? But regardless where
it's mounted it'll still maintain a constant temp, right?
Robert (duck & cover) Harmon
--
http://tinyurl.com/pou2y
http://tinyurl.com/fkd6r
Remove "Z" to reply via email.
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Date: 23 Oct 2006 18:31:56
From: Jack Denver
Subject: Re: Reply from Presisia about sub-$200 PID equipped machine.
|
Wherever the TC is mounted it will try to maintain that temperature
constant. But if the TC is mounted on outside of the boiler there may be
some lag in between the time the steam cools off (or heats up) and the time
the metal cools off (or heats up). Because steam is a gas temperature
change is almost instantaneous. The greater the lag the less precise the
control because you end up with over/under shoot. Imagine you are trying to
maintain a precise speed in a car but that the speedometer had a delay of
several seconds on it- by the time you saw that you had reached your speed
limit you'd in fact be going faster. Then you'd slow down until you saw that
you were below the limit and you'd end up going too slow. Etc.
Of course in a HX the steam temp only directly influence the brew temp and
flushing/stand time has a big influence. On most machines, you want steam
temp to be in the range of 120 to 125 C to get a brew temp of 90 to 95C
after a flush of the water standing in the HX. This also gives you decent
steam pressure in the range of 1 to 1.3 bar (gauge).
"Robert Harmon" <r_h_harmon@Zhotmail.com > wrote in message
news:Xns9865ABBBBBDFErhharmonZhotmailcom@207.217.125.201...
. So it seems that you're saying that to get the most
> responsive reading from the TC it would be better to mount it inside the
> boiler where the steam is, namely the to inch or so? But regardless where
> it's mounted it'll still maintain a constant temp, right?
>
> Robert (duck & cover) Harmon
> --
> http://tinyurl.com/pou2y
> http://tinyurl.com/fkd6r
> Remove "Z" to reply via email.
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Date: 23 Oct 2006 09:16:22
From: Randy G.
Subject: Re: Presisia PID, is it too good to be true?
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I just emailed them so we shall see.. Click to view the "larger image"
it has been Photoshopped (IMO). For example, examine the flow of the
espresso as it exits the right-hand spout and how it is entering the
cup on the right as well..
If this is worth owning, it appears that a grinder is now approaching
nearly twice the cost of the espresso machine! But for most folks who
want to enter the world of espresso, a PID'd machine with quality
grinder at around $400 total is a tempting price point.
But.. If I have to predict I imagine aluminum boiler and PF body, lots
of plastic inside (and out), but we shall see....
Randy "if it sounds too good to be true..." G.
http://www.EspressoMyEspresso.com
"Robert Harmon" <r_h_harmon@Zhotmail.com > wrote:
>
>I was looking at some PID's I was told about in another post & came across
>what seems like an interesting machine.
>
>http://auberins.com/index.php?main_page=product_info&cPath=6&products_id=20
>
>Precisia Espresso Machine w/PID - $185?
>
>There is a speculative discussion about it on CoffeeGeek, but no ones seems
>to have actually had their hands on one. I was just curious if anyone here
>has actually seen one & used it?
>
>http://www.coffeegeek.com/forums/espresso/machines/260258
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Date: 23 Oct 2006 16:33:30
From: Robert Harmon
Subject: Re: Presisia PID, is it too good to be true?
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Randy G. <frcn@DESPAMMOcncnet.com > wrote in
news:hdqpj29v1v4in21kr2r0qsjm9t18a70v7p@4ax.com:
> I just emailed them so we shall see.. Click to view the "larger image"
> it has been Photoshopped (IMO). For example, examine the flow of the
> espresso as it exits the right-hand spout and how it is entering the
> cup on the right as well..
>
> If this is worth owning, it appears that a grinder is now approaching
> nearly twice the cost of the espresso machine! But for most folks who
> want to enter the world of espresso, a PID'd machine with quality
> grinder at around $400 total is a tempting price point.
>
> But.. If I have to predict I imagine aluminum boiler and PF body, lots
> of plastic inside (and out), but we shall see....
>
>
> Randy "if it sounds too good to be true..." G.
> http://www.EspressoMyEspresso.com
>
>>
>>http://www.coffeegeek.com/forums/espresso/machines/260258
>
Yeah I know the tune to TANFL (there aint no free lunches). But for those
moving up from a steam pot to their first 'real' espresso machine this
might be a good starting point. Whether it's worth the money will be
determined by impartial testing. But, while I'm curious...
Robert (...just not yellow!) Harmon
--
http://tinyurl.com/pou2y
http://tinyurl.com/fkd6r
Remove "Z" to reply via email.
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