mitch236 wrote: The problem with autotune is the PID is only reading a stable boiler while just sitting.

AutoTune should be started when the boiler about 20-40°F below idle point, machine dependent.

mitch236 wrote:It isn't measuring the variations during a shot.

A PID is measuring at all times. Its reaction is determined by the settings. Whether AutoTune is better or worse than a manual tune is dependent on factors too innumerable to list.

Using someone else's numbers could be far worse than AutTune, again depending on innumerable factors

There are many threads about different methods for reading temps but a Scace device is (IMO) the easiest and best. Putting the thermocouple into a pf spout won't work because you need some restriction to flow. I've tried putting the probe on a bed of coffee which works fairly well but you need to make a new shot with every measurement. There are some folks who have constructed a flow restriction pf device similar to the Scace but for setting the PID which you will only do once, it still would be more cost effective to rent the setup.

The other benefit of the Scace is once you set the PID, you can work out a pre-shot ritual to determine what gives the best temp control during the shot. In my case, if I run the pump for 6 seconds prior to pulling the shot, my shot temp is as stable as I could get.

There's one for rent over at Coffee Geek. I don't have the link but I know Dan does (HB here). Maybe he will chime in.

cafeIKE wrote:Using someone else's numbers could be far worse than AutTune, again depending on innumerable factors

Using someone else's numbers who is using the same machine as your's will get you in the ballpark. You would still want to fine tune. When I installed the PID in my Linea, I used Greg Scace's suggested numbers as a starting point, but since he has a two group Linea and mine is a single group, my ultimate settings were different but not by a lot.

mitch236 wrote:Using someone else's numbers who is using the same machine as your's will get you in the ballpark.

Someone else's numbers might get you in the ball park IF your sensor is the same, your heater is the same, your inlet water temp is the same, the sensor location is the same, the sensor scale is the same...

IF using a kit with identical components, it's a relatively safe bet, assuming the installer didn't hork it up.

The OP

leopm wrote:Just got some PID stuff to put on my Gaggia Twin...

I'm betting on AutoTune

You could be right Ian. I enjoyed setting up my PID. I learned a lot about temp stability and realistic expectations. I learned a lot about how PID's work, what they are capable of and what they are not capable of. I also learned what my machine is capable of and how to best control the variables. Granted my machine is a true commercial design and not representative of the typical home machine. Auto tune may be easy and get you working but tuning the PID yourself will educate you about what to expect from your machine.

Well,

Read the Greg Scace's article. VERY useful. Gonna try.

Thanks for helping!

Leonardo