My homemade digital temperature controller!

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reinhart36
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Joined: Mon Mar 31, 2014 11:24 am

My homemade digital temperature controller!

Post by reinhart36 »

Hi All,

I'm stopping in to showcase my long term hobby project, which I've recently completed.

I got a large Big Green Egg in 2010, and have loved it and used it extensively. I wanted a temperature controller so I could do other things (such as sleep) while smoking or drying things.

I've chipped away at a few iterations of one over the last couple of years, and am now completely finished.

Check out this video of it in use:

https://vimeo.com/90480641

Please let me know what you guys think! I'm looking for questions / comments and general interest and feedback.

Thanks for having a look!

Eric
Dave
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Re: My homemade digital temperature controller!

Post by Dave »

Wow! Fantastic Eric, great job.

From what I can see it looks great.

Cheers, Dave
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reinhart36
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Joined: Mon Mar 31, 2014 11:24 am

Re: My homemade digital temperature controller!

Post by reinhart36 »

Dave wrote:Wow! Fantastic Eric, great job.

From what I can see it looks great.

Cheers, Dave
Thanks Dave!
urbangriller
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Re: My homemade digital temperature controller!

Post by urbangriller »

Interesting!

Great work on the build!

You are controlling the temp with the top vent only, what was your bottom vent set at?

Cheers
Chris
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reinhart36
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Re: My homemade digital temperature controller!

Post by reinhart36 »

urbangriller wrote:Interesting!

Great work on the build!

You are controlling the temp with the top vent only, what was your bottom vent set at?

Cheers
Chris
Hi Chris,

Thanks! The bottom vent is set wide open for any operating temperature, so that the top vent is guaranteed full authority over the airflow rate.

Please let me know of any other questions.

Eric
Smokey
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Re: My homemade digital temperature controller!

Post by Smokey »

Im thinking having the bottom vent full open and the top vent choked lends itself to a "dirty" fire.
How do you get around that?
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Golly
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Re: My homemade digital temperature controller!

Post by Golly »

grate work
how about making a version for the weber kettle
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Gumb

Re: My homemade digital temperature controller!

Post by Gumb »

That's a brilliant gadget....love your work.
Basher
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Location: Brisbane

Re: My homemade digital temperature controller!

Post by Basher »

Very clever Eric.
Must be vitally important to ensure all seals are in tip top condition- at the moment, mine are not! :oops:
Otherwise, open bottom vent will continue to draw and make it tough to lower temps.
The dual temp reading is brilliant. Probe in the food and one controlling the vent.
How much for a kit with the probe?
You will never know until you have a go!
Nath
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My homemade digital temperature controller!

Post by Nath »

Smokey Mick wrote:Im thinking having the bottom vent full open and the top vent choked lends itself to a "dirty" fire.
How do you get around that?
Good call Mick.

Awsome looking controller mate! I'm assuming you could close down the bottom vent to half, and it would still be able to control it by opening the top vent further.


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Nath
Smokey
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Re: My homemade digital temperature controller!

Post by Smokey »

Busio90 wrote:
Smokey Mick wrote:Im thinking having the bottom vent full open and the top vent choked lends itself to a "dirty" fire.
How do you get around that?
Good call Mick.

Awsome looking controller mate! I'm assuming you could close down the bottom vent to half, and it would still be able to control it by opening the top vent further.


Sent from my iPhone using Tapatalk
My observation is purely being interested and thought provoking. Have you tested it with bottom vent choked to 6mm and then let the controller do its thing?
You might get a longer running time.
I love the idea 8)
If trees screamed when we cut them down, We wouldn't. If they screamed all the time we would.
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Nath
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My homemade digital temperature controller!

Post by Nath »

Yer would love to know the results of that also.
Hopefully one day you can make them commercially available.


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Nath
reinhart36
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Re: My homemade digital temperature controller!

Post by reinhart36 »

Smokey Mick wrote:Im thinking having the bottom vent full open and the top vent choked lends itself to a "dirty" fire.
How do you get around that?
Thanks for the question. It's interesting, I'd never heard of a dirty fire until I started getting questions on this thing. My experience is limited to ceramic grills, which are so thermally efficient, the fuel is always just barely burning. But in general, here is my take on it:

If you think about it, for a given situation (charcoal type, humidity, etc., etc.) temperature is a function of airflow rate. So, for a given circumstance, there is a particular flow rate needed for a particular temperature. Thus, whether the flow rate is being governed by a restriction at the inlet vs. the exit, there is still the same amount of dirty air leaving the grill, and the same ammount of clean air entering the grill as long as you are indeed maintaining the same temperature.

Have you guys had other experiences? I wonder if for steel / drum type smokers where there are more substantial fires, this dirty fire thing becomes an issue?

Very interesting!
reinhart36
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Joined: Mon Mar 31, 2014 11:24 am

Re: My homemade digital temperature controller!

Post by reinhart36 »

Smokey Mick wrote:
Busio90 wrote:
Smokey Mick wrote:Im thinking having the bottom vent full open and the top vent choked lends itself to a "dirty" fire.
How do you get around that?
Good call Mick.

Awsome looking controller mate! I'm assuming you could close down the bottom vent to half, and it would still be able to control it by opening the top vent further.


Sent from my iPhone using Tapatalk
My observation is purely being interested and thought provoking. Have you tested it with bottom vent choked to 6mm and then let the controller do its thing?
You might get a longer running time.
I love the idea 8)
That's an excellent idea. No, I haven't tried it, but now I'm going to! :D

I'll let you know what happens. Thanks to all for the interest and compliments!

Eric
reinhart36
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Joined: Mon Mar 31, 2014 11:24 am

Re: My homemade digital temperature controller!

Post by reinhart36 »

Basher wrote:Very clever Eric.
Must be vitally important to ensure all seals are in tip top condition- at the moment, mine are not! :oops:
Otherwise, open bottom vent will continue to draw and make it tough to lower temps.
The dual temp reading is brilliant. Probe in the food and one controlling the vent.
How much for a kit with the probe?
My seals are several years old and are showing their wear, but they work well enough. I agree though, if you're too leaky, then the controller doesn't have the authority it needs. I bet bad seals would be especially problematic if if you were trying to cook at very low temps and it was really windy.

I haven't considered making/selling kits, but I could give it some thought. Building mine "one off," there were almost exactly $200 USD in parts in the controller and servo. I got the metal parts cut for free by a friend. I'm not sure what a shop would charge for those in prototype quantities. Probably pretty cheap since they're just cut out of a plate of sheet metal by an NC laser (or mill).

Thanks for the thoughts - much appreciated!
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