HomeRoast Digest


Topic: PID for a Gaggia (17 msgs / 319 lines)
1) From: Sheila Quinn
Speaking of the PID, I've been wondering this for a while.... Has anyone 
here every PID'd a Gaggia, in particular a Gaggia Baby? I would love to 
have that on my machine, but I've never heard of anyone doing it. I 
would imagine it's possible, but how difficult is it?
Thanks,
Sheila

2) From: Michael Wascher
PIDing almost any machine would be similar. Probably not difficult. But then
the PID's parameters need to be tuned to the machine's dynamic
characteristics (how fast does it heat up & cool down based on the size of
the heating element, size of the boiler, mass of metal getting
heated/cooled).
Can anybody out there with hands' on experience describe how easily that is
accomplished?
On Jan 5, 2008 5:05 PM, Sheila Quinn  wrote:
<Snip>
-- 
"About the time we think we can make ends meet, somebody moves the ends."
--Herbert Hoover

3) From: Barry Dryden
Sheila,
Check outhttp://www.blog.nashlincoln.com/espresso/gaggia-espresso-pid-arduino-modRegards,
BarryD

4) From: Mike Koenig
Michael,
Are you referring to tuning the PID??
Many of them have an auto-tune function, that's fairly adequate.  I
usually auto-tune mine, then tweak from there, (usually I lower the I
parameter a bit),  works fairly well for me.
At one point Greg Scace wrote a nice post to alt.coffee about tuning
PID's for espresso machines.  You can search alt.coffee for it at
groups.google.com.
--mike
On Jan 5, 2008 5:12 PM, Michael Wascher  wrote:
<Snip>

5) From: Sheila Quinn
Oh boy... looks more complicated than something I can tackle myself! 
Wish I knew someone in my area who's good at tinkering with this stuff. 
Thanks for the link.
Sheila
Barry Dryden wrote:
<Snip>

6) From: Mike Koenig
Sheila,
that link is for a microcontroller mod, which is a bit more than a PID
(but a very interesting concept).  If you know some basics of
electronics, and can follow the wires to the heater,  it's not that
hard.  Most machines are wired the same way, so if you check out any
of the Silvia mod pages, you can follow the same concepts.
--mike
On Jan 5, 2008 7:00 PM, Sheila Quinn  wrote:
<Snip>

7) From: Barry Dryden
Just found this linkhttp://home.earthlink.net/~r_harmon/PID/index.htmwhich seems to have kits for sale.  I don't know if this is current
information or not.
BarryD

8) From: Sheila Quinn
Thanks! I will check into these.
Barry Dryden wrote:
<Snip>

9) From: raymanowen
Rest assured, it is completely within the capability of an amateur to do a
botched installation of a PID temperature controller. The temperature of the
sensing probe will be kept stable, not necessarily the temperature of the
shot brew water in the coffee puck.
Brass is used to fabricate the group and filter handle components of
espresso machines Only because it is fairly easy to machine. Brass has about
the lowest thermal inertia of any metal you could machine. Bronze is higher,
as are stainless steel and even solder. Water itself is FAR higher.
("joules/Kg-degree" is the term.)
"Marine Brass" refers to Navy Commanders. The heated water provides most
thermal stability, not the brass.
Cheers, Mabuhay -RayO, aka Opa!
Advertising palaver...

10) From: Sean Cary
Hey, I am Marine Brass also...hopefully Marine Silver Brass next year since
I am up for LtCol this year...yeah, start the prayers early I need them.
Sean
I feel way to young to be a LtCol...they are all old and crotchety.
On Jan 6, 2008 9:07 AM,  wrote:
<Snip>
-- 
Sean M. Cary
Major USMC
Tempus Fugit, Memento Mori

11) From: raymanowen
Yes, Sir!  How much and Where, Sir?
Cheers, Mabuhay -RayO, aka Opa!
On Jan 5, 2008 11:29 PM, Sean Cary  wrote:
<Snip>
-- 
"When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Mighty
Wichita (ex- NYC Paramount) WurliTzer- 1976

12) From: Sheila Quinn
I'm sure it is, but I'm not asking about a botched job...I'm asking 
about how to do it RIGHT! :)
Not sure it's something I'd even want to attempt myself at this point. 
I'd hate to screw up my machine and have it be useless. Oh well.
Thanks,
Sheila
raymanowen wrote:
<Snip>

13) From: David
There is a thread over on CG about this, as well as
installing an OPV in a Gaggia.
--- Sheila Quinn  wrote:
<Snip>http://sweetmarias.com/maillistinfo.html#personalsettings<Snip>">http://lists.sweetmarias.com/mailman/listinfo/homeroast<Snip>http://sweetmarias.com/maillistinfo.html#personalsettings<Snip>
Looking for last minute shopping deals?  
Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping

14) From: Sheila Quinn
I'll check that out -- thanks!
David wrote:
<Snip>

15) From: raymanowen
"...how to do it RIGHT!"
What is your definition of RIGHT?
You could easily outspend a whole new Baby, trying to make it RIGHT.
What problem currently manifests itself, the first cause of which is Lack of
PID control? Before you tie up any funds in a different control device, I
suggest you write down the exact problem you are experiencing, with its
observable effects (shot defects).
Duplicate the problem and take notes several separate times. With this
degree of awareness, perhaps you will be able to diagnose the proximate and
ultimate cause. Once you have done that, more than one solution will become
obvious.
Try to choose the solution least expensive, easiest to implement, with
maximum results. If a PID controller is the outcome of such diagnosis, be
aware that a correct installation is unique and different if it's even
feasible for each type of machine.
A PID is a controller, which means that it can control a heater from
overheating a process. If the machine has quadrants of operation in which
the process measurand demands heat faster than the heater can supply it (the
heater is underpowered), the PID doesn't make heat. The process could fail
completely or marginally. [How close is Good Enough?]
Good brewing practice demands a certain temperature and pressure of water
within the "puck." Since the pump and heater are elsewhere and the process
is dynamic, temperature and pressure gradients exist within the shot brewing
volume. It is unlikely that the desired brewing dynamic ever exists within
the puck on a low powered (120v, 15a) home espresso machine.
You could increase the *virtual* size of your heater by pre-heating the
water supply, thereby reducing the actual heat it needs to supply- smaller
steps are easier to accomplish. Or, you could boost the  actual heat
delivered by the heater by boosting its supply by 6v - 20v.
With either mod you could really use the PID *controller*, but the machine
would probably draw more than 15a - 20a at 120v when the heat is on.
How many home machines maintain an adequate heated brewing water reservoir
with an E 61 brew group?
QED
Cheers, Mabuhay -RayO, aka Opa!
On Jan 6, 2008 8:04 AM, Sheila Quinn < quinngraphics> wrote:
<Snip>
-- 
"When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Mighty
Wichita (ex- NYC Paramount) WurliTzer- 1976

16) From: stereoplegic
WAY too expensive!
i'd recommend ebay seller ColdfusionX for the Solid State Relay (SSR, 
don't know if they have smaller than 25Amp, but it's better to have too 
much than too little), because their SSR's don't require a heatsink (and 
thus take up less space). for the electrical wire cut up a $ store 
extension cord (16 guage for the heating element). for everything else, 
there'shttp://www.auberins.com/(individual links to "everything else" 
below)
      Universal 1/32 DIN PID Temperature Controller
      
      Temperature sensor for Rancilio and Gaggia Espresso machine
      
(this RTD temp sensor isn't completely necessary but will screw right in 
where the brew thermostat is now, and will allow you to make 1/10th 
degree F or C temp adjustments).
      *Controller project box
      *
(also not necessarily necessary, any hard plastic box will do. cut a 
slot for the PID in the front, and a hole for the wires in the back or 
on the side, depending on how/if you chose to mount the box).
here's a link to the site i followed when installing mine:http://www.thedomesticbarista.com/content/view/17/27/Barry Dryden wrote:
<Snip>

17) From: stereoplegic
WAY too expensive!
i'd recommend ebay seller ColdfusionX for the Solid State Relay (SSR, 
don't know if they have smaller than 25Amp, but it's better to have too 
much than too little), because their SSR's don't require a heatsink (and 
thus take up less space). for the electrical wire cut up a $ store 
extension cord (16 guage for the heating element). for everything else, 
there'shttp://www.auberins.com/(individual links to "everything else" 
below)
      Universal 1/32 DIN PID Temperature Controller
      
      Temperature sensor for Rancilio and Gaggia Espresso machine
      
(this RTD temp sensor isn't completely necessary but will screw right in 
where the brew thermostat is now, and will allow you to make 1/10th 
degree F or C temp adjustments).
      *Controller project box
      *
(also not necessarily necessary, any hard plastic box will do. cut a 
slot for the PID in the front, and a hole for the wires in the back or 
on the side, depending on how/if you chose to mount the box).
here's a link to the site i followed when installing mine:http://www.thedomesticbarista.com/content/view/17/27/Barry Dryden wrote:
<Snip>


HomeRoast Digest