Just PID-dling Around! - UPDATED w/Cook Photos

Bill Arnold

1974
Staff member
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Thomasville, GA
Yep, it's my turn to have a go at partially automating my meat smoking process. After reading through Brent's thread and seeing folks on a smoker thread posting about a controller, it was time to see how I could do with it. My parts list is much the same as Brent's; the main difference being the addition of two indicator lamps - one for power on; the other for relay on. When I was ready to order, Amazon listed a 'kit' that included the MyPin TD4 PID, SSR-25A relay and a heat sink for about $38. The type K probe was about $5. I spent about $20 at Radio Shack for connectors and a switch. Add some scrap wood and you got it.

As I started getting parts together, I connected various items in turn to test as I went along. I began to get a bit of a rat's nest.

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The "blower" is almost cute! All one needs for my application is 4-5cfm. This little guy puts out 4.2cfm. It will be used in place of the damper on the side firebox. Any more air flow than this would blow ashes into the cooking chamber.

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The project did include a bit of woodworking. Nothing fancy, though - serviceable is enough!

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Time to break everything down and mount it in the boxes. From left to right: blower, main switch, PID, SSR/Heat sink, power outlet for the 12v power supply to feed the blower.

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It fits with a little room for wiring!

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Even the little guy has a home now.

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And - it works again! A note here: After doing this assembly, I tested the probe/PID in the kitchen. In boiling water, the probe read 212°F on average, varying a degree or two depending on where it was in the water. In a glass of ice water, it showed a temp of 36°F.

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I mounted the probe in the back center of my smoker at cooking grate level.

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Now, some techy stuff. One of the things I've heard universally is the lack of documentation on the operation of the MyPin T series PIDs. I took Brent's setup and numbers as a starting place, but kept playing around with different settings. I also did a bit of research just to get a handle on PID terminology, which also helped. One thing I did NOT like about the way the PID was controlling the SSR is the switching on and off when the probe temperature was near the desired temperature. I kinda figured the hysteresis settings should have some control over the range of temperature in which the SSR would be switched; however, no matter how I set any of the hysteresis points, nothing changed. After I had read the instruction sheet for the umpteenth time, I finally saw the phrase, "Not available when P is not OFF". So, I went through the setups, switched P(Proportional band) OFF. Now, the Control Hysteresis is in play, meaning I can set the hysteresis at 10, my desired probe temperature at 225°F and the blower will turn off at 225°F and back on at 215°F. Stating it otherwise, whatever probe temperature I set, the PID will control the system over a +/-5° range (220-5=215, 220+5=225).

So, here are my settings:
P = OFF
I = 132 (Brent's number)
d = 36 (Brent's number)
HYS = 10 (or whatever range you need)

My next step is to start preparing the beef brisket, beef ribs and pork spare ribs I bought to cook Saturday!!!
 
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Nice!

I've got a little store bought unit I can hook up to my Weber grill to do the same thing. Basically add more air when the temp drops and cut of the air when the temp goes up.

I think I need to relook at my pid numbers, as I think the heating elements in the smoker could probably actually handle the rapid cycling induced by the 'proportional' control.

But with the fan, I can see why you would not want to use the P, (Maybe Rob can chime in, he seems to understand this stuff a lot better than I do).
 
Go Bill Go....:)
I am getting set for MK2 version. With the way my memory is behaving lately my recall of the whole thing is zero just like a movie i watch and next day cannot recall until i get into it. So i will chime in again when i get to play with MK2.
I think you got it Bill. Being able to dabble with the actual hysteresis is great.
I am not able to recall what Brents settings were i did not use them. Still think these units are incredible for the $ when you consider what they do. Have fun Bill.
What u doing for meat temp measuring?
Do you do anything to alter total duration when smoking like wrap the meat during the stall?
Thats the reason i wanted a second unit just to act as a temp monitor and alarm. Next enclosure will also be wood.

Sent from my SGH-I337M using Tapatalk
 
Go Bill Go....:) ...

What u doing for meat temp measuring?

Do you do anything to alter total duration when smoking like wrap the meat during the stall?

...

Thanks, Rob!

I have a digital meat thermometer for checking the meat temps.

I'm not sure it falls into the "alter" category, but I do 3-2-1 (smoke, wrap, smoke) on pork ribs. A 2-2-1 cook is recommended for baby backs - I'll find out about that later today since I have one rack of BB and two of spares. It's been a while since I did pork shoulder, but I'll wrap when it hits the stall, then open again afterward. For beef brisket, I've always left it unwrapped the full cook. For just about everything, when I take it off the smoker I put it on a platter with foil over it for 15-30 minutes before serving.
 
These are from last Saturday - forgot to post - bad on me!

Smoke's rising.
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Start of cook. Beef brisket, beef side ribs and short ribs.
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Three hours into the total cook. Added pork spare ribs and trim cuts to the smoker. Wrapped the beef ribs. Threw a link of kielbasa on for a quick warmup.
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Six hours into the total cook. Three hours on the pork ribs - time to wrap with squeeze margarine, turbinado sugar, a dash of rub and a squirt of apple juice for moisture. On the far right, a bit of moisture for the chef!
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Closeup of the ribs with the goodies before they go back on the smoker.
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I got all excited about having the pork ribs ready to eat, plus LOML and a neighbor were harassing me, so I didn't get photos before we cut them up and dove into them.

Beef ribs ready to go. Brisket has nine hours on it and will stay on the smoker overnight to finish.
Qs_20140621f.jpg

Take my word for it - everything was yummy!
 
These are from last Saturday - forgot to post -...........

Aw man, & I forgot to show -up on time :doh: there was so much humidity here that day, that my mind must of been clouded due to all the 'moisture' :D.......

& From the looks of it, there had to be some mighty happy stomachs at the end! :thumb:

and to think, some say smoking is bad for your health...:rofl: what little do they know!
 
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