Autotune Results

[rjprice]

Hi all,  Been reading up on my new #3.  Just got an Auber, mounted the Fixed Box temp sensor, bypassed the stock controller and ran an autotune.  Got some funky results:

P=76 (reasonable)
I=283
D=320

The stock numbers are:
P=70
I=600
D=150

Foiled, Used 2 bricks for a heat sink, and a water pan.

Do the I & D results look weird?

Thanks!

 

[DivotMaker]

Not at all.  The stock parameters are for a Bradley smoker, so don't use them for a reference.  The numbers really don't matter, as long as the controller is maintaining temp properly.  Have you tried it with food since the autotune?

 

[rjprice]

Thanks! Actually, trying some ribs/Brats as we speak. 

I saw the autotune results thread and mine were different by a mile.  I re-ran the AT and got the exact same values as Wik in the autotune results thread:  75,715,89.  My bricks we still a tad warm so that may be some of the difference.

 

[DivotMaker]

It will vary by model, too.  My results in the #2 are quite a bit different from yours.

 

[rjprice]

I noticed that there was what seemed to be significant variation from the set temperature.  I have the program set for 225 and it would fluctuate to like 230 or so.  Is that normal?  It was a little windy.

 

[DivotMaker]

Wind is tough sometimes, and may account for the difference, but that's a little high for an Auber.  Even in the wind, I rarely see more than a couple degrees difference.  Your issue could be probe placement.  If you're using the drop-in probe, you need to make sure it's as close as possible to the location you had it in for the autotune.  Remember, it was reading from that exact location, so any variance could make it react differently.  That's the main reason I love the wall-mount probe; that variable is completely removed!

 

[rjprice]

I did the permanent box probe which is why I was surprised about the variation from the set point. I set the auber to ramp up to 140 for .5 hrs and then 5.5 hrs at 225.

If I want to test the auber, can I use the bricks for a heat sink and no wood?

 

[DivotMaker]

RJ, you are correct about bricks with no wood (smoke won't affect your autotune).  You want to make sure the smoker is setup as close to "actual" cooking conditions as possible.  When I autotune, I foil the bottom and lid of the smoke box, and poke a hole in the drain hole, just like for cooking.  Add a water pan next to the smoke box, and 2-3 bricks (not foil-wrapped or anything) on a shelf as high as possible. 

If you set the autotune parameter as you have, and enter the program at the time of the autotune (don't use a "stored" program, you should get an accurate tune.  If it's not stabilizing closer than 5°, you may want to repeat the tune. 

 

[rjprice]

Good idea to re-test.  I had foiled the bottom and used a water pan.  The temp fluctuations occurred when I smoked 2 slabs of St Louis ribs and 12 Brats after autotuning.

 

[rjprice]

I re-ran the auto tune and the Temp never varied more than 2 degrees from the set point.  It was real windy, too.  I did not pull the new PID values but it's working good now.

I spatched and brined a whole chicken, smoked it at 140 for .5 and 225 for 2.5 (a little too long) and the put it in the oven at 350 for .5 to try to crispen the skin.  Next time I will smoke less and oven cook a little more.  The brine made a huge difference.  Even overcooked, it was juicy.  I still want the crisp skin, though. Gonna try 45 mins at 350 next time. I'm totally down with the Auber, now.

 

[DivotMaker]

Great news, RJ!