Arpi wrote:Oops. I think it is the "PV offset" the one you want to change (not the SV offset). All it does is to tell the pid to read higher or lower by so many degrees. For example, if you set it to -5F, then the temperature at the boiler will be +5F than the temperature displayed. If you match this value to the temperature difference between the boiler and the head, then the pid will display the temperature at the head.

Keep raising the pid temperature till you get 200F at the head (water running-shot), then the pid display value minus 200 is the offset value you would put in the "PV offset" variable so that the temperature of the head and the display match.

Cheers

That makes sense. I also realize that a Silvia is no comparison, but I did find offset values on the Silvia to be about 20F different from the boiler to the head, just figured this machine shouldn't be that much of a difference. I am currently running stable at about 213(SV) and I will do more measurements after about an hour of idle rest, to see how close I am getting to 198F.

Does anyone know the approx. volume to flush, to clear out the AV of it's cooled water?

Euology101 wrote:Does anyone know the approx. volume to flush, to clear out the AV of it's cooled water?

For me with my single group Linea with Piero cap (puts the flowmeter in the cap), my pre-shot flush is 6 seconds. You might have to add about 2 seconds to clear your flowmeter but that's not the whole problem but close enough. Also, If you read Greg's paper on setting temps, you should throw away the first two seconds before the measurement starts.

ok, Just want to make sure I understand this correctly....

I have the SV set at 212f and then I go in and set the PV Offset to -13f (This is what I am finding based ony my crude measurements). When I do this, I notice the PV is instantly lower, but then the heater kicks on and tries to go back up to the SV of 212f. Because of this PV Offset being programmed in, do I now need to set the SV to say, 198f?? I just want to make sure I am doing this correctly.

mitch236 wrote:For me with my single group Linea with Piero cap (puts the flowmeter in the cap), my pre-shot flush is 6 seconds. You might have to add about 2 seconds to clear your flowmeter but that's not the whole problem but close enough. Also, If you read Greg's paper on setting temps, you should throw away the first two seconds before the measurement starts.

I've noticed it takes about 6oz, or 35 seconds roughly, to get the temp up around where I think it should be. This seems like a lot, but that being said, the whole point to Piero Caps is to fix this exact issue? I also notice if I pull a few shots in succession, it maintains the temp pretty well, so I'm guessing this is a good thing.

When you have the offset correctly set, the SV should be set to whatever temp you want to brew with.

I never measured how much volume comes out in 6 seconds but that's how long I run the pump without the pf before I lock in the shot.

*Sitting at my desk, I'm relying on memory alone and its been quite a while since I set up my PID.

Wait a minute!! Are you telling me that with a double boiler L.M. machine with PID I still need a flush, just in this case a warming flush? I thought the advantage of DB machines was fixed brew temperature? I guess the group cools off and the control system, with the sensor in the boiler, can not detect that.
KDM

mitch236 wrote:When you have the offset correctly set, the SV should be set to whatever temp you want to brew with.

I never measured how much volume comes out in 6 seconds but that's how long I run the pump without the pf before I lock in the shot.

*Sitting at my desk, I'm relying on memory alone and its been quite a while since I set up my PID.

Thanks, That is what I needed, makes sense. I think it's time I rent the Scace...

duke-one wrote:Wait a minute!! Are you telling me that with a double boiler L.M. machine with PID I still need a flush, just in this case a warming flush? I thought the advantage of DB machines was fixed brew temperature? I guess the group cools off and the control system, with the sensor in the boiler, can not detect that.
KDM

Well you have to remember, a 2 group machine isn't typically meant for home use... In a commercial setting, if this thing was pulling shot after shot the groups would hold temp, and the water inside the lines leading to and from the flow meter would not be stagnant, and therefore warm. This (I Believe) is only because of the setting that it is currently in... AKA, my living room.

Hi.

Since you don't have a Scace (I don't either), you could use a method called "lip over". You get a thin thermocouple and place it over the lip of a full portafilter (with coffee grounds). Then, carefully, lock the portafilter in place (well, maybe not all the way). Since you are only concern about the temperature and not how the coffee taste, you leave the portafilter there till you are done with your measurements. That is, you use the same coffee for several shots.

Cheers

Justin,

If you do find a scace to borrow let me know - I'd like to fine tune my machine as well

I am making some progress with it! The brew boiler is fully finished and tested - good to go

now just waiting on some parts to finish the steam boiler and then I could really enjoy the machine

As far as the offset on pid it's exactly what it sounds like. If you set the offset to 5, and set temp to 195, it'll make the temp 200

so either you can figure out the difference in temp from group to boiler, make that your offset and set whatever temp you want for your coffee or you can set offset to 0 and just add that boiler-to-group difference to your goal temp and put that as your set value

both would have the same effect

godlyone wrote:Justin,

If you do find a scace to borrow let me know - I'd like to fine tune my machine as well

I am making some progress with it! The brew boiler is fully finished and tested - good to go

now just waiting on some parts to finish the steam boiler and then I could really enjoy the machine

Ilya,

Check out Dan's post, 3rd one in this thread, and you will see a link to rent the Scace.

-Justin