# How to PID



## badger28 (Jan 5, 2013)

Hey,

As requested I have written a quick guide as to how I added a PID to my gaggia classic. It isn't comprehensive but should give the general idea.

If anyone spots any errors please let me know!

And if anyone has any more questions then give me a shout. The word document is the best one, but there is a pdf too.

https://dl.dropboxusercontent.com/u/97796915/Gaggia_classic_pid.docx

https://dl.dropboxusercontent.com/u/97796915/Gaggia_classic_pid.pdf

Looks like the ebay seller of the pid and ssr has stopped selling them, however this one is the same I think...http://www.ebay.co.uk/itm/100-240V-AC-Digital-PID-Temperature-Controller-25A-SSR-Heat-Sink-K-Sensor-/221302652447?pt=UK_BOI_Industrial_Automation_Control_ET&hash=item3386aa7e1f

Cheers,

Nick


----------



## c_squared (Jun 26, 2013)

Thanks for this nick. I've had my eye on putting a PID on my classic. Once I read this properly, then re-read it I might just be in a position to actually be able to achieve it!


----------



## urbanbumpkin (Jan 30, 2013)

Great effort Nick.

Where did you source the PID from and how much did the components cost in at?


----------



## badger28 (Jan 5, 2013)

No problem. I thoroughly recommend reading the original guides which I followed as the people who wrote those understand the electronics far more than I do.

However I thought that the pictures from my classic should help as I tried to focus on the connections to give clarity.

PID and SSR were sourced from ebay. I think I put the link on the guide, although cannot remember now.

PID and SSR £30

Wires £5

Connectors £6

Project box £5

Thermocouple £5

So about £50.


----------



## unoll (Jan 22, 2014)

I've been desperately searching for a source like this as there seems to be alot of schematics and rough how to's out there but few decent guides. *Big thanks Nick!!!* Now all I need is the gear and a bit of time with my electronics toolkit. I'm toying with the idea of hooking up a dimmer switch to the pump at the same time but think I'll figure out the PID first and I'm doing ok with cracking open the steam at the moment.


----------



## Mike mc (Apr 10, 2012)

Thanks for this


----------



## Pompeyexile (Dec 2, 2013)

OK so I'm going to ask a really dumb question now. Firstly here is a picture of the PID on my Gaggia...

View attachment 5501


Now for the dumb question...My Gaggia came with it already added and what do the top and bottom figures represent? I haven't a Scooby what to do and why, other than I know it's got something to do with steady boiler temp....I think.

Also is this yet another factor as to why my recent attempts at pulling a decent shot have gone awry?


----------



## badger28 (Jan 5, 2013)

Green numbers look like the temperature it is set to.

The red number looks like what the temperature is actually at.

It won't be accurate ie 90c won't actually be 90c. But it will be consistent. So just keep adjusting the temperature setting to find at what temperature the coffee tastes nice. Mine was at about 98c I think.


----------



## Pompeyexile (Dec 2, 2013)

Thanks Badger. The lower green figure is what it came set at which I guess the previous owner did and I haven't touched it because as I said I didn't know what the figures really meant. Now you've enlightened me I understand but I thought 90 was about right for coffee as I have a kettle that has temp settings for tea, coffee and green tea, that I use for when I'm making Cafetiere coffee and for that it is pre-set at 90 degrees and cannot be adjusted. I also read somewhere that boiling water burns coffee but 98 isn't boiling so I'll try it a bit higher and see what happens.

By the way the machine hadn't been on that long which I guess is why the top figure showed 84 but it carried on climbing after I took the photo and steadied out at 90 too.


----------



## badger28 (Jan 5, 2013)

I think it depends on where the thermostat is located and how accurately it measures the boiler temperature.

There is also a difference between boiler temperature and the temperature when the water hits the coffee so I found it best to get some beans that you know well and just play until it tastes good!


----------



## sub7 (Nov 8, 2012)

I was looking into how to install/what I need to install a Sestos PID/SSR that I have ordered. I stumbled across one of your posts but it seems the drop box links no longer work. Is it possible if you could re-upload the guide you made ?


----------



## sub7 (Nov 8, 2012)

Having spoke with badger28 on PM he advised he files are corrupt in dropbox. Does anyone else by any chance have them saved anywhere ?


----------



## majnu (Jan 31, 2014)

Can badger not restore previous versions in dropbox?


----------



## majnu (Jan 31, 2014)

Also how does the pid compensate for when you get a rush of fresh water into the boiler when you hit the brew switch?

Should the thermocouple be located as close to the brew head as possible? What's the ideal location?

Cheers


----------



## Neill (Jun 26, 2013)

majnu said:


> Also how does the pid compensate for when you get a rush of fresh water into the boiler when you hit the brew switch?
> 
> Should the thermocouple be located as close to the brew head as possible? What's the ideal location?
> 
> Cheers


The problem is it can't compensate. A PID simple provides a smaller dead band for turning the element on and off. What it does give you is a much more accurate starting point. Temp will always drop as you but the brew switch unless you get in to pre heat coils. My thermocouple is screwed in to the original thermal well in the boiler.


----------



## badger28 (Jan 5, 2013)

Sadly not. It only restores within 30 days of the original version being deleted.



majnu said:


> Can badger not restore previous versions in dropbox?


----------



## Jim bean (Aug 16, 2014)

It would be great if some one had a copy of the original document they could copy and paste


----------



## joe (Nov 13, 2014)

Jim bean said:


> It would be great if some one had a copy of the original document they could copy and paste


Anyone?... please.


----------



## Jim bean (Aug 16, 2014)

Hi Jo

here's instructions for PID with added steam alarm function

http://coffeeforums.co.uk/showthread.php?19674-DIY-PID-Steam-and-Brew

PID just with brew this is using the auber PID but can be used with any PID

http://kabalin.blogspot.co.uk/2014/03/gaggia-classic-controlling-temperature.html

Cheers James


----------



## joe (Nov 13, 2014)

Excellent.. many thanks for the reply.


----------

