Originally Posted by BluesDaddy
Great stuff, takes a lot of guess work out of it. I've been using my Tiger for the first time today. I didn't see this until just now, so I've been pretty much doing trial and error. I just set one stage for 235°, but it has pretty much wanted to stay at 250° (which is not a bad temp for smoking a pork picnic). I hit manual periodically and the temp will come down, but even before it gets down to 235° if I put it back on auto the fan comes back on and drives the temp up. I'm guessing I don't have it set quite right.
I am using reverse flow offset, REVERSE 282 at www.allchinas.com
, grilling size 282" square inches, lining by stove mud, gravity feed burner, and Tiger.
When warming up the grill this morning, I did extensive test.
I set I=0 and D=0
The Bigger the P, the SLOWER the temperature rising.
The smaller the P, the FASTER the temperature rising.
Finally I set P=5 (default is 30)
As my gravity feed burner is also reverse flow, when the fan stops running, the hot air/smoke will stop entering the grill immediately. So it is hard to overshoot.
I set target temperature at 200C,(not F), It varied between 198C to 200C,
In your common sense offset firebox, If you set P=5 and I=0.D=0, it may overshooting.
But you can tuning P,I,D by set I=0 and D=0.
Try different P, say 5,10,30,50,100, find the best P for you.
When you find P, set P there and try Different I, say I=10,30,60,100
and finally try D.
Then You can use P, or PI, Or PID, whichever behvoirs best in your smoker.
ASLO PLEASE SET UDC=90
But if you use my Gravity Feed Burner, it is very easy to tune P,I,D.
Even the PID is not correct, it will keep temperature much more stable
Also my burner can burn automatically for 10+ hours
Also my burner can burn broken charcoal, chips,chunks. These are cheaper than pellet. Or you can mix a small portion of pellet with charcoal.
With my burner and controller, temperature swing will be under 3F.
But for a warranty promise, I guarantee 5F.(leave a small safe room for me)
I am going to do beef jerky.
I set it at 60C or 140F
As I first did test by 200C or 392F on my grill.
I do not open the cover.
It has been two hours and the pit temperature is still 77C or 170F
How great the lining by stove mud is!
It must be agreat help to do low and slow smoking