TJ-066 Roaster PID setup

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
joalepins
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#1: Post by joalepins »

Hi,

I'm currently doing initial setup of my new TJ-066 500g roaster from Mill City and I have a question about the offset value you need to adjust on the machine's PID.

The roaster came with a guide book and there's a section about the PID setup where it tells you to set a desired offset value.

How do I know exactly what value to enter ?

In the book, they set it to -20.0 but is it suitable for my roaster ?

Thank you !

Jo

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keno
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#2: Post by keno »

My understanding of the offset is that it would be used if you have two or more temperature probes and they are not giving identical readings at baseline room temperature. So, for instance, if the bean temp is reading 5 degrees higher than the exhaust temp you could apply a -5 degree offset to the bean probe or a +5 degree offset to the exhaust probe. Shouldn't matter for a single probe unless it's off from the actual ambient temperature in which case you could also adjust it.

Another possibility is that you want your temps to be consistent with other roasters for more comparability of profiles. For instance, if they typically hit first crack at 380F and you hit it at 400F then a -20 degree offset would put you in line with them.

But don't fret too much about it. As long as you're getting reasonable readings you should be fine. Precision is not as important as getting consistent repeatable feedback.

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slickrock
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#3: Post by slickrock »

keno wrote:My understanding of the offset is that it would be used if you have two or more temperature probes and they are not giving identical readings at baseline room temperature.
Not to steal the the thread... wondering if there is feature like this for Artisan and/or TC4. At steady state my ET and BT probes are off by nearly 5-8 degrees.
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keno
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#4: Post by keno replying to slickrock »

Does this answer your question?

Artisan roaster - offset temperature (phidget)

Dregs
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#5: Post by Dregs »

slickrock wrote:Not to steal the the thread... wondering if there is feature like this for Artisan and/or TC4. At steady state my ET and BT probes are off by nearly 5-8 degrees.

In Artisan, go to Config>Device>Symb ET/BT. In either or both of the 2 open boxes, type in "x+number", without the quotes, where number is the number of degrees of offset you want to add.

Edit: Oh, I see Keno beat me to it.

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JK
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#6: Post by JK »

Artisan is xspace+space# if I remember correctly..
space is a keyboard space like in between words..

Also you will be asked your Bruad rate for the TC4-C after changing this..
It defaults to the fastest and may not work for your model..

I don't think the video Steve made on the PID changes the offset..
https://youtu.be/f3mrZKf0A2M
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jgbnm
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#7: Post by jgbnm »

joalepins wrote:Hi,

I'm currently doing initial setup of my new TJ-066 500g roaster from Mill City and I have a question about the offset value you need to adjust on the machine's PID.

The roaster came with a guide book and there's a section about the PID setup where it tells you to set a desired offset value.

How do I know exactly what value to enter ?

In the book, they set it to -20.0 but is it suitable for my roaster ?

Thank you !

Jo
Take a guess to start, then watch the roaster while warming up to see how the different temps vary, then can adjust again. Make a note of the temps during a roast as well and can adjust as necessary after that. For me, I just wanted my BT reading to be about what is normal at first crack. Also wanted my PID and BT to be about the same at my typical drop temps.
The more I learn, the more I realize just how much there is to learn.