Hi folks.

I am looking for tips I am learning how to roast with a PID and becoming aware of its possibilities. So far it is nice. My thinking is that the 'soak' portions (temp flat for a periods of time) is only good for warming up. And for the real roasting, the 'ramp' mode is the only one used.

As my first batch, I'll try to do a light roast (most difficult). I can program how steep are the ramps and for how long. So I programed only 3 legs (out of 16).

1) 8 mins till 200F after damping beans
2) 8 mins till 350F
3) 10 mins till 430F

This is what I got

Brasil Facenda Ipanema Dulce



It seems I got a nice and long time from 1C (390F) till I finish I wanted to get a light roast but after seeing that it had a very smooth curve on top I let it stay longer je je. At the end I got a medium roast. The beans are nicely crunchy but I will not try them till tomorrow morning.

Do you guys have any tips?

TX

What did your P, I, D, Ar settings end up at??

Hi Gyro.

I did the day before an autotune (with empty drum) at 300F and this is what I have now:

P = 7.3
i = 172
d = 33.1

If you are interested, I can email you the hole file.pxg so that you can downloaded into your pxg4. They call 'upload' to read the PID into the laptop. And they call 'download' to write a file into the PID. If it were me, I would have call it backwards. I did the mistake to 'download' the computer.pxg file that came with the software into the PID. Then I did an autotune jeje.

I tried a shot of the roasted Brasil beans just now and they came out good.



So my first PID roast was good after all jeje but I wonder what I am missing from not chosing the 'best' parameters or the best times, temperatures, etc..

Cheers

How did your roast go in relation to your target curve though? Mine was poor, and it suffered in the cup as well. Are you controlling via BT or ET?
I did a 'self-tune' instead of 'autotune' and it tightened the numbers considerably, but I've yet to try it on with the new dataset on an actual roast.
Finally got the roaster/computer interface up and running, so will have a crack at it tomorrow.

My thermocouple sits at the very edge of the green beans. It depends on volume. So it is a 'mix' of ET and BT.

I think the PID did good keeping the time spans for being the first time. It did a little bell at first in the 200Fs, but that did not had an impact I think.

I think the best would be to sacrifice a batch and do an autotune at 390F with the drum loaded.

Cheers

I think I came up with a super roast in my second PID attempt I can taste some fruit and bean characteristics just by chewing on the beans. I took a peak at my previous data for the sidamo and I came up with these three legs:

leg 1: 180F to 300F 8 mins
leg 2: 300F to 370F 4 mins
leg 3: 370F to 435F 10 mins

1C = 385F

The PID settings were so so. The PV value was lagging somewhat at the first part of the roast. At the last part of the roast, it was the other way around but the end was magnificent.





I did the changes you mention in the other PID thread. It is nice to have decimal points

I just did a shot and the perfume and flavor are super excellent

That's it for me till next weekend. I got my two roasts.

VIVA PIDs!!

Arpi, did you just plug the PID into the computer and it worked? Mine will communicate with the loader program,but whenever I plug it into the computer, the PV goes to LLLL. Did you change any settings or anything, I'm a bit stumped.

I tried taking the panel off the roaster incase a wire was a bit cramped in there (the loader cable is pressed hard against the base of the roaster body) but it didn't make any difference. Although I've put it back now and when I plug it in it reads UUUU and doesn't talk to the loader program either!

Its been a frustrating exercise, but I am getting closer with manually tuning parameters that actually work. So far I think I am settled on a very aggressive P setting of 0.2 with a set value range of 0-250C. On my roaster at least, the power needs to get on quickly if it starts falling behind the curve as there is a lot of thermal inertia.

I'm still working on the best I setting, but a D of around 20 is working nicely so far for anticipation values.

Its taking me a long while to get my head around some of these PID settings. Being a high school dropout and all

Cheers, Chris

Hi Gyro,

You may have set limits that prevent operation. Check the values of P-SL (lower limits) and P-SU (upper limits).
If the pv reading was above or beyond the limits, you would get that display (LLLL or UUUU).

Another weird possibility is incorrect wiring at the back. It could be either wrong holes used or a fake electrical contact. I think I saw a different pinout being used in one of your pics. Even though it looks as if the wires are in the hole, they may not be making a good contact. I would back the screws all the way back and put the wires in. Then I tighten the screws.

If anything fails, reset to factory conditions and try again. I think I have my file saved in the laptop if you want it.

Cheers

Its very strange. Works fine until I plug it in, then PV reads LLLL or UUUU. With the loader cable unplugged, all is good.