I'm not too sure whether I got involved in smoking meat for the food or just to fiddle with something.
I do know that I was inspired by the Cookshack Amerique- just think, set the temperature of the smoker and the temperature you wan the meat done to and walk away. Too bad the Amerique is $1600.
I figured that it could be made for cheaper, especially if you don't need as large of a smoker. After all, how hard could it be?
I had a pretty good idea how to start- take an existing smoker, add a new temperature control that you can electronically adjust, add a separate meat probe and put it all together.
I started with a Cookshack because it seemed that other electric smokers still needed wood added every few hours or so, whereas the Cookshack only needed it put in at the very beginning. Maybe I was mistaken, I don't know, I didn't research it that thoroughly. Anyway, I started with a Cookshack refurb that hopefully would not be cheaper than all the mods I was planning on doing.
No, actually, I started with the PID control- the smoker didn't come until after I was pretty certain I had all the correct electronics to make this work.
I mostly started with a lot of pieces from Auber Electronics since they were relatively cheap and it one-stop shopping. I got their 1/32 DIN temperature controller, 25amp SSR, the associated heat sink, a platinum RTD temperature sensor and some connectors- a K-thermocouple and an RTD connector.
The really important piece was still missing- a temperature controller that could handle multiple set points. A Fuji PXR goes for over $200 which I was really reluctant to invest in. Eventually I found an Ogden ETR-9300 on eBay. It had one aux input that could be used for a second setpoint (among other uses) The only problem was that it didn't have a SSR output, just two relay outputs.
Taking a chance that I could convert one of the relay outputs to SSR, I bought the Ogden controller for $65. Luckily, it was relatively straightforward to take out one of the relays and have it directly drive the SSR output.
I figured that all you needed to drive and SSR output, you just needed to take the relay drive voltage and pull it straight out to the terminals. Well, sort of. This is where the manual was very helpful- it indicated that there were 33 ohm resistors in series with the drive voltage. There were even resistor outlines on the PC board under the relay after I removed it.
So, I had all the parts except for the meat probe and a housing. I picked up a project box (and power switch, fused IEC connector, output plug, and fuses) from my local electronics retailer. I could figure out the meat probe later.
To test what I had, I assembled the controllers in the project box and used it to control a rice cooker in a sous vide setup (look it up yourself). With the auto tuning, the rice cooker kept +/-1 degree.
I made a sous vide chicken (160 degrees- way over temperature- next time I'll let it dwell at 150 instead. I could even let it dwell at 140 for an hour if I wanted to kill off most nasties).
I made a boiled egg (65 degrees C is what the blogs say- the problem is that the white is still too runny for my taste).
I was ready for smoking, so I bought the Cookshack SM-008.
Blah, blah, blah, this is getting boring, even for me. Let's get to the pictures.
Here's the PID controllers in the project box:
On the top you see the heat sink for the SSR. To the left is the Auber 1/32 DIN temperature controller and on the right is the Ogden 1/16 DIN temperature controller.
The Auber controller is used to measure the temperature of the meat. It is set to a simple On-Off mode: you set it to the temperature you want the meat to hit- if it's too cool it turns the relay on and when it hits the target temp it will turn its relay off. I put in a bit of hysteresis so even if the meat cools down a lot, it won't turn the relay back on. Right now, the display is showing the SetValue (target temp). The problem with a single line display is that it can't show both the SetValue and the ProcessValue (current temp) at the same time. Normally it will just show the PV, but if you press the up or down arrows, it'll show the SV and allow you to increase or decrease it.
The Ogden controls the smoker temperature. The relay from the Auber feeds its aux input. When the relay is on, the Ogden will use SetPoint2, when the relay is off, it will use SetPoint1. I'd like SP2 to be the hold temp and SP1 to be the cooking temp, but it will take a bit of effort to make it work that way, until then, this works fine enough.
Around the back
you see the K-thermocouple plug for the meat probe, the RTD connector for the smoker temperature, the output plug for the smoker and the input IEC socket (like on the back of a computer) to plug into the wall. Note that the cord pictured is 18 gauge and it resulted in a 2 volt drop. I have since replaced it with a 14 gauge cord though I haven't measured the voltage drop across that one.
You can't see it but the IEC connector has the fuse below, and of course, the power switch is in the upper right.
Here's a photo of the Ogden where I'm adjusting SP2 to 225 degrees:
and here's where SP1 is being shown:
So, if you were keeping track, the smoker will run at 225 until the meat reaches 180, then it should drop down to 140.
I was lazy and just hooked the RTD sensor over the smoker's stock temperature sensor in the back:
it's the little black piece sticking out at an angle back there.
Here's a shot of the meat probe in a boneless short rib:
continued....
I do know that I was inspired by the Cookshack Amerique- just think, set the temperature of the smoker and the temperature you wan the meat done to and walk away. Too bad the Amerique is $1600.
I figured that it could be made for cheaper, especially if you don't need as large of a smoker. After all, how hard could it be?
I had a pretty good idea how to start- take an existing smoker, add a new temperature control that you can electronically adjust, add a separate meat probe and put it all together.
I started with a Cookshack because it seemed that other electric smokers still needed wood added every few hours or so, whereas the Cookshack only needed it put in at the very beginning. Maybe I was mistaken, I don't know, I didn't research it that thoroughly. Anyway, I started with a Cookshack refurb that hopefully would not be cheaper than all the mods I was planning on doing.
No, actually, I started with the PID control- the smoker didn't come until after I was pretty certain I had all the correct electronics to make this work.
I mostly started with a lot of pieces from Auber Electronics since they were relatively cheap and it one-stop shopping. I got their 1/32 DIN temperature controller, 25amp SSR, the associated heat sink, a platinum RTD temperature sensor and some connectors- a K-thermocouple and an RTD connector.
The really important piece was still missing- a temperature controller that could handle multiple set points. A Fuji PXR goes for over $200 which I was really reluctant to invest in. Eventually I found an Ogden ETR-9300 on eBay. It had one aux input that could be used for a second setpoint (among other uses) The only problem was that it didn't have a SSR output, just two relay outputs.
Taking a chance that I could convert one of the relay outputs to SSR, I bought the Ogden controller for $65. Luckily, it was relatively straightforward to take out one of the relays and have it directly drive the SSR output.
I figured that all you needed to drive and SSR output, you just needed to take the relay drive voltage and pull it straight out to the terminals. Well, sort of. This is where the manual was very helpful- it indicated that there were 33 ohm resistors in series with the drive voltage. There were even resistor outlines on the PC board under the relay after I removed it.
So, I had all the parts except for the meat probe and a housing. I picked up a project box (and power switch, fused IEC connector, output plug, and fuses) from my local electronics retailer. I could figure out the meat probe later.
To test what I had, I assembled the controllers in the project box and used it to control a rice cooker in a sous vide setup (look it up yourself). With the auto tuning, the rice cooker kept +/-1 degree.
I made a sous vide chicken (160 degrees- way over temperature- next time I'll let it dwell at 150 instead. I could even let it dwell at 140 for an hour if I wanted to kill off most nasties).
I made a boiled egg (65 degrees C is what the blogs say- the problem is that the white is still too runny for my taste).
I was ready for smoking, so I bought the Cookshack SM-008.
Blah, blah, blah, this is getting boring, even for me. Let's get to the pictures.
Here's the PID controllers in the project box:
On the top you see the heat sink for the SSR. To the left is the Auber 1/32 DIN temperature controller and on the right is the Ogden 1/16 DIN temperature controller.
The Auber controller is used to measure the temperature of the meat. It is set to a simple On-Off mode: you set it to the temperature you want the meat to hit- if it's too cool it turns the relay on and when it hits the target temp it will turn its relay off. I put in a bit of hysteresis so even if the meat cools down a lot, it won't turn the relay back on. Right now, the display is showing the SetValue (target temp). The problem with a single line display is that it can't show both the SetValue and the ProcessValue (current temp) at the same time. Normally it will just show the PV, but if you press the up or down arrows, it'll show the SV and allow you to increase or decrease it.
The Ogden controls the smoker temperature. The relay from the Auber feeds its aux input. When the relay is on, the Ogden will use SetPoint2, when the relay is off, it will use SetPoint1. I'd like SP2 to be the hold temp and SP1 to be the cooking temp, but it will take a bit of effort to make it work that way, until then, this works fine enough.
Around the back
you see the K-thermocouple plug for the meat probe, the RTD connector for the smoker temperature, the output plug for the smoker and the input IEC socket (like on the back of a computer) to plug into the wall. Note that the cord pictured is 18 gauge and it resulted in a 2 volt drop. I have since replaced it with a 14 gauge cord though I haven't measured the voltage drop across that one.
You can't see it but the IEC connector has the fuse below, and of course, the power switch is in the upper right.
Here's a photo of the Ogden where I'm adjusting SP2 to 225 degrees:
and here's where SP1 is being shown:
So, if you were keeping track, the smoker will run at 225 until the meat reaches 180, then it should drop down to 140.
I was lazy and just hooked the RTD sensor over the smoker's stock temperature sensor in the back:
it's the little black piece sticking out at an angle back there.
Here's a shot of the meat probe in a boneless short rib:
continued....
