Auto Tuning - Group Results

[TexasSmoke]

Thanks Tony!

So if it was no longer flashing AT and I turned it off while still in my program did I still get good numbers?

Was the 6 bricks to many?

[DivotMaker]

Ron, if it stopped flashing, you were OK to turn it off...that means it was done.  No problem with 6 bricks, either!

[SuperDave]

Ron, I've done 2 auto tunes and both stayed at 140 for the entire auto tune period.  My auto tunes both took a little over 1 1/2 hours which as you say was much longer than program 1 was set.  All is good on the working end though.  You should be fine tomorrow for a test cook.

[TexasSmoke]

It's interesting it never makes it to program 2. It makes me wonder should we start the 1st program at 225 so it would test at the temp we normally smoke at.

[DivotMaker]

The program really doesn't matter, Ron, so long as there is a program.  The older units tuned a little differently than the new GPH models.  I may modify the autotune instructions to reflect that.

[FunkedOut]

Wik, great thread; I suggest making this a sticky.
I have some data points to contribute.

I received a WSD-1500GPH this week and got the wall-mount probe installed on my SI3, 3/4" from the top of the chamber with a 1/2" spacer behind the rear wall.  Started playing with it.  Here's what I got:

Contributor	P	I	D	SI Model	Air Temp	Meat/Lbs	Start/End	ByPassed	Notes
Valid Range	1-999	0-999	0-999
Preset	70	600	150
FunkedOut	106	999	734	#3	90F	empty	Start	Yes	set temp = 100F; auto-tune = 5.5 hours; no wood
FunkedOut	80	765	191	#3	90F	empty	Start	Yes	set temp = 200F; auto-tune = 1.5 hours; no wood
FunkedOut	72	510	127	#3	90F	empty	Start	Yes	set temp = 300F; auto-tune = 1.5 hours; no wood
FunkedOut	57	441	110	#3	90F	empty	Start	Yes	set temp = 400F; auto-tune = 1.4 hours; no wood

I want to point out the values I put in the Valid Range row. 
Both, the manual on the auber site (v.1.0) and the manual that is on the CD included with the unit (v.1.5) list the "Range" for P, I and D the same as the values you listed in your original post.  However, when playing with the unit, I am able to set the P, I and D values anywhere from 0/1-999.  The 100F auto-tune yielded results for both I and D that are out of that range.

Looks like when trying to tune with the set temp (100F) only 10F above the ambient temp (90F), the unit calculated a value for I approaching infinity.  This says the SI3 is outside of its operating range in those conditions; cold smoking conditions.  I need to try an auto-tune with set temp to 100F and the cold smoking plate and a block of ice...

I hypothesize that increased airflow, say by adding a small fan blowing air into the chamber would have similar impacts to the PID values as does increasing the set temp.
Increased temperature results in more convection (airflow) which slows down the heating of the box a bit and also cools it down faster.
The difference between a fan and increased temp is the difference from ambient temp.  The higher the temperature of the chamber, the greater the temperature difference, the faster the chamber will cool down towards ambient.
Maybe a fan would bring the SI3 into proper operating conditions under cold smoking conditions.

While I am on the airflow discussion, I would like to bring up that I have an extra drip hole at the rear of my SI3 bottom, doubling my airflow and changing the system behavior a bit.  This hole is where I plan to enlarge and add a fan.
Although, at the moment (just before adding the auber), the SI3 was making great BBQ. 
I don't want to mess up a good thing.

[FunkedOut]

Collected a couple more data points after enlarging my rear airflow hole to 5/8" (front drip hole is still 3/8"):

Contributor	P	I	D	SI Model	Air Temp	Meat/Lbs	Start/End	ByPassed	Notes
Valid Range	1-999	0-999	0-999
Preset	70	600	150
FunkedOut	49	407	101	#3	83F	empty	Start	Yes	set temp = 400F; auto-tune = 1.4 hours; no wood
FunkedOut	45	389	97	#3	83F	empty	Start	Yes	set temp = 400F; starting temp = 400F; auto-tune = 1.4 hours; no wood

Although I don't have a fan, enlarging the hole certainly increased airflow and had the same effects on the PID values as increasing the set temp.  Compare my previous post entry for set temp = 400F.

Today's second entry is almost identical to the first.  The only difference between the two is that the second entry was the result of an auto-tune initiated with the smoker already at the set temp (400F).  I was wondering if the initial warm up and overshoot was affecting the auto-tune calculations so I ran this second auto-tune to test the theory.  Such small differences in value indicate that the auber is not affected by starting at 0F and climbing up to temp.

[DivotMaker]

Interesting data, Funk, but I would caution you against using a 400° setpoint.  According to Steve, the box is not rated higher than 350°, so you are risking damage, going to 400.

[Limey]

Although in some earlier posts he indicated that 500 degrees was OK.

[DivotMaker]

Although in some earlier posts he indicated that 500 degrees was OK.

Please find those posts.  I have discussed this with Steve, and the factory engineers have stated 350 as the rating.

[FunkedOut]

http://smokinitforums.com/index.php?topic=1041.msg4314#msg4314
http://smokinitforums.com/index.php?topic=1015.msg4067#msg4067

those are the two I found.  Both by johnnytex where he says he got the 500*F number from Steve.  There are several posts by you (DivotMaker) saying you got a 350*F number from Steve.  Could not find any posts by Steve or any info on smokin-it.com regarding the rated temp value.

I'd love to know the truth, not the safe margin for warranty claim value, and not the head buried in the sand value.
Really, the stainless will hold up fine and so will the element and wiring.  It's the insulation rating that we need to worry about; at least for me, having removed the original controller.
I've modified my SI3 and plan to keep it for a long time.
I don't plan to cook above 250*F often, but like to run the temp up to 400*F for a good crisp/bark/sear/burn for a short while at times.

[DivotMaker]

I'd love to know the truth, not the safe margin for warranty claim value, and not the head buried in the sand value.
Really, the stainless will hold up fine and so will the element and wiring.  It's the insulation rating that we need to worry about; at least for me, having removed the original controller.
I've modified my SI3 and plan to keep it for a long time.
I don't plan to cook above 250*F often, but like to run the temp up to 400*F for a good crisp/bark/sear/burn for a short while at times.

Funk, we're both right.  Early on, when JohnnyTex talked to Steve, the 500 number was mentioned.  However, 350 is the number he is sticking with now.  Not to say the box can't support a higher temperature, just be assured it will be solely at your own risk.  Personally, I'll think you'll find trying to take your #3 to 400 will be a painfully slow process, and not worth the effort (your meat will be done way before it hits that temp).  If you need a high-temp finish, just pre-heat your oven so you can transfer to it straight out of the smoker.  This is a smoker, not an oven.  Steve told me he will not endorse going above 350 in his smokers.

[FunkedOut]

Thanks for checking in again on this, Divot.
I'd venture to guess that materials have not changed from 2013. 
I did buy my #3 about the time johnnytex made those posts.

Totally agree on the at-my-own-risk part.  I never was under the impression that these products came with a warranty anyway.

As far as getting to 400F, the #3 gets there in 40 minutes from being completely cold.  It's good to go. 

At any rate, 350*F is plenty high enough for a smoker.  Plenty high.
Thanks again.

[DivotMaker]

I never was under the impression that these products came with a warranty anyway.

As far as getting to 400F, the #3 gets there in 40 minutes from being completely cold.  It's good to go. 

At any rate, 350*F is plenty high enough for a smoker.  Plenty high.
Thanks again.

Warranty is 3 years - longest of any like these!    400 in 40 minutes is great!  I haven't gone higher than 235 in my #3 yet, but that big element does heat up fast.  I tried 325, with chicken, in my #2 and it was done long before hitting 325!

"At any rate, 350*F is plenty high enough for a smoker.  Plenty high." -- Agreed!

[allmann]

Installed the probe and by passed the switch yesterday. Auto tuned today with a large brick and a can of water. Set the program, it didn't follow it, and it ranged from the high 120s to the high 170s.

the final #s
P= 80
I= 600
D= 303



I will be testing it out tomorrow on a few racks of ribs.