Need everyones help on a PID problem

Mr Walleye · February 04, 2008, 02:58:49 PM

Quote from: pensrock on February 04, 2008, 02:45:53 PM
It also seems odd that he was able to complete three autotunes in such a short period of time.

WildCat

To expand on what Pensrock said... How long does it take to run the auto tune?

Something doesn't add up....

Mike

pensrock · February 04, 2008, 02:59:48 PM

If you pick the probe up so it is not touching anything inside the smoker does it still keep bouncing? Did you check to make sure the wires are tight on the back of the controller?

Wildcat · February 04, 2008, 03:02:26 PM

It takes about 2 to 5 minutes for the autotune. I will go change the temp probe so that it will just hang and will get back in a few.

Mr Walleye · February 04, 2008, 03:02:31 PM

Sorry WildCat... I have to head home for supper. I will be back shortly & see how you are making out.

Mike

Mr Walleye · February 04, 2008, 03:04:47 PM

Quote from: Wildcat on February 04, 2008, 03:02:26 PM
It takes about 2 to 5 minutes for the autotune. I will go change the temp probe so that it will just hang and will get back in a few.

Wow

Non of the autotunes I have ran were that quick! I think the fastest was about 30 minutes. Did you pay attention to the display temps as it was autotuning? It should overshoot then undershoot about 3 times.

Mike

pensrock · February 04, 2008, 03:05:02 PM

I have never used an Auber but most autotunes take anywhere from 1-3 hours. I suspect the fact that the temp is jumping around in the instrument that it is getting kicked out of autotune.

Tiny Tim · February 04, 2008, 03:08:35 PM

I'm assuming your chicken is pretty close to done by now...just for kicks, when it is, take a couple of bricks or something and put them in the position you usually put the meat in...start autotune, then leave it alone for an hour or so, then see what it's doing.

Wildcat · February 04, 2008, 03:26:30 PM

Moved the probe and is simply hanging above the meat. Chicken at 135. Probe temp reading climbed steadly to 225. No jumping. Of course it did this before then started jumping. This time it slowly went down to 211 and is now slowly climbing. No jumping. One problem fixed. I think I should try another auto tune and see if it works this time. What do you guys think?

pensrock · February 04, 2008, 03:28:23 PM

Yes, I think the autotune was shutting off due to the bouncing you were seeing on the controller.

Wildcat · February 04, 2008, 03:57:10 PM

Thanks to all of you. Been running the auto tune for about 25 minutes now and it is still tuning. Wish I knew what was causing the bouncing before. It was not touching metal the other day. Seems to be working now though. I also moved my Maverick probe to be near the PID probe. There is about an 11 degree difference between the two. Maverick showing a lower temp. May need to get a more accurate PID probe in the future if this thing calibrates itself alright. In the mean time, I will just set the PID about 10 degrees higher than I want to cook at.

pensrock · February 04, 2008, 04:07:24 PM

Talk to iceman when he get back home. I think he uses these type of probes, see how he mounts it. It's possible you do have a defective probe, maybe the wires inside the insulation are bad? Its hard to tell without actually being there.
Good luck, pensrock.

pensrock · February 04, 2008, 04:10:01 PM

Also, your PID controller should be more acurrate than the Maverick. Most digital controllers are +- 5 degrees F. Maybe the probe is the correct reading and the Maverick is off a few degrees? Just a thought.

Wildcat · February 04, 2008, 04:17:05 PM

I checked the Maverick today in boiling water. The cabinet probe went between 209 and 211 and the meat probe between 210 and 213. I think the boiling point of water is 212.

The auto tune went for 25 minutes. The temp swings are now from 216 to 222. The Maverick is roughly 10 degrees lower. May have to do another auto tune. Any other recommendations for a smaller temp swing?

The chicken has been in there for 3 hours now and is only registering a temp of 135. I seems strange that it is still at that temp. It is skinless and boneless breasts and vent is a little over half open.

Wildcat · February 04, 2008, 05:25:05 PM

Ran auto tune one last time for tonight. Took another 25 minutes. Numbers are P=544 I=161 D=166. Let it run at 220 for awhile and had a temp swing of 219 to 221. Looks like goal is met. Maverick temp reading 9 to 11 degrees less. I just bumped the PID setting to 230 so that I can get the chicken done. Will probably be dry. If so, the dog has some treats to look forward to.

Thanks for all your help guys. It appears that now all I need to do is get another temp probe for the PID.

pensrock · February 04, 2008, 05:55:29 PM

Your within two-three degrees now. It may get even better with another tuning but I would write down the numbers before changing anything. Some controllers will allow you to enter an offset to make the controller match what the maverick reads, I'm not familiar with the Auber so I do not know if you can offset it. I'm happy it looks like it is working now for you. The dog is probably happy too!