After messing around for a good long while, my P1 has a ramping PID
controller on it. Considering I just got the first three roasts on it, I
have to say it works pretty sweet. Bit I still have some tuning to do
Here is what I've seen so far.
Plugged into the wall, it does fine for slower ramps. About 10F per
minute. After a bit of tuning it will stay with a degree or two of the
set point. However, it did a pretty good job of falling on its butt
around first crack. Had a tough time keeping up. I can't say that I'm
surprised since it was the first roast, and hadn't been fully tuned yet.
So I held it about 440, cut the fan back some, and set it into autotune
again. Ended up with some columbian into rolling 2nd.
2nd try, tuned better, but still fairly nasty around 1st. cut the fan
back, hit hold until the temp caught up & shut it down. 3'rd time, I
kicked the variac back into the circuit. Was hoping to be able to run
without it, but the P1 with 225gr, and no fan turn down just can't hold
as tight as a I wanted. Still 3 to 4 degrees C lagging at ~ 220. Kick up
the variac a bit more and it pulled in better. So the variac is back,
and running at about 130.
Figure I'm going to have to soften the initial ramp some, to get over
the initial start-up lag. Don't want all 130 hitting the slow moving
beans. I'm going for a no fan adjust setup, so I'll stick a few extra
points at the low end.
Once I get it working the way I want, I'm going to start logging bean
temps so that I can compare repeatability of the profile. Once I get a
good repeatable profile, I figure I will finally be at the place that I
can start to learn what changes in profile really mean to the final