Author Topic: Auto tune on 3d  (Read 1459 times)

Jeffinn

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Re: Auto tune on 3d
« Reply #15 on: June 08, 2016, 08:04:03 PM »
So as an experiment I set up the following program:
C1 135 degrees E1- t T1 1.5
C2 155 degrees E2 - t T2 1.5
 Used the same two bricks as I used for the auto tune (in the same place in the smoker)

Here's what the auber showed on its display:
0.3 hrs. 143 degrees (8 degrees over)
0.5 hrs. 141 degrees (6 degrees over)
0.7 hrs. 142 degrees (7 degrees over)
0.8 hrs. 138 degrees (3 degrees over)
1.0 hrs. 133 degrees (2 degrees under)
1.2 hrs. 130 degrees (5 degrees under)
1.4 hrs. 135 degrees
1.6 hrs (when the program switches to 155 degrees
1.6 hrs. 141 degrees
1.8 hrs. 157 degrees (2 degrees over)
1.9 hrs. 161 degrees (6 degrees over)
2.0 hrs. 163 degrees (8 degrees over)

I finally stopped the test because it was obvious that the smoker wasn't holding the temperatures correctly. This is disappointing. For the extra $200 I was expecting this unit to hold the temperatures much more effectively.

Jeff

DivotMaker

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Re: Auto tune on 3d
« Reply #16 on: June 09, 2016, 05:24:23 PM »
Jeff,

If you only had 2 bricks in a 3D, that's probably not that bad.  That's a lot of airspace to control with very little heat sink.  I use these numbers in my 3D, based on an autotune I had done in a standard 3 with the standalone Auber PID:

P  62
I  900
D  112

They hold pretty tight, so I'm happy.  The stock numbers worked for me, too, but these are just a little better (at least in mine).  This is simply a programming issue, not any kind of failure of the controller.  These boards are accurate, but if you try to hold temps within a degree or two in essentially an empty box (2 bricks vs. volume of space), it's very hard for the controller to adjust for that.  However, even the variations you show are well-below the temperature swings of the analog controller, and BBQ isn't unforgiving.  There's guys with stick burners that would kill for temps that close! ;)   Not trying to make light of your disappointment, but this is a smoker, not a scientific test chamber.

One more thing - in the temp numbers you posted, you can pretty much disregard the .3, .5 and .7 hour readings.  This is the heat-up phase, and it will never be exact (the element has to heat, and then cool).  This period also has absolutely NO effect on the outcome of your meat.  Sometimes it takes around an hour, or so, to "settle in" and maintain the same temp.  As you saw around the one hour point, it was pretty close.  Had you let this program run longer, I have no doubt it would have stabilized very close to 135, which by the way, is a very low temp to smoke at, so this was truly a "stress test!" 

When it switched to 155, you also did not give it time to get through the heating phase.  Please remember that this is an electric element that doesn't heat & cool instantaneously.  You only gave it 18 minutes to stabilize!  Not enough.

If it were me, I would throw a big ol' pork butt in there, set the program to 225 until it hits 190 internal, and eat some BBQ!  I think you are over-analyzing how rapidly the controller can work, and expecting more than any electric element can deliver.  It is extremely more accurate than any stick burner, and other analog-controlled electrics.  No offense, my friend, just my 2... :)
Tony from NW Arkansas
"Official Smokin-It Test Pilot"
Smokin-It Model 1, 2D conversion, and 3D
Auber PID, NexGrill 896 6-burner, CharBroil Big Easy, Anova Precision Cooker w/WiFi
Wife, Son and One REALLY Big Dog!

Jeffinn

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Re: Auto tune on 3d
« Reply #17 on: June 09, 2016, 06:12:25 PM »
The numbers were similar last week with 10 pounds of snack sticks in the smoker which is why I'm playing with it now.
 I'm not looking for a scientific test chamber, I'm looking for a smoker that delivers on it's promise of accuracy.
 135 may be low for the smoking that you do but I use that temp from time to time for various sausage recipes.
 I cant see a valid reason for the over-shoot when the smoker switches from 135 to 155. The box is already pre-heated and the heating element should be able to edge up to 155 without overshooting by 10-12 degrees which is where its at today by the way).
 The whole point behind the Auber controller is having a certain degree of accuracy. Their website claims their controller will hold temps within 1 degree of the set temperature. While I Realize that theres a certain amount of marketing hype to those types of claims, I dont think its out of line to question 10 degree temperature swings with the Auber controller.
 Your suggestion that I should throw a pork butt in there and enjoy some barbecue was un-necessay and unhelpful.
 I'll continue working with Steve as he seems somewhat interested in identifying what the issue is.
 I wont bother posting about this again in this forum.
Jeff

DivotMaker

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Re: Auto tune on 3d
« Reply #18 on: June 09, 2016, 06:28:25 PM »
Your suggestion that I should throw a pork butt in there and enjoy some barbecue was un-necessay and unhelpful.
 I'll continue working with Steve as he seems somewhat interested in identifying what the issue is.
 I wont bother posting about this again in this forum.

I'm sorry you feel that way, Jeff, but I stand by my recommendations.  Good luck to you, Sir.
Tony from NW Arkansas
"Official Smokin-It Test Pilot"
Smokin-It Model 1, 2D conversion, and 3D
Auber PID, NexGrill 896 6-burner, CharBroil Big Easy, Anova Precision Cooker w/WiFi
Wife, Son and One REALLY Big Dog!