[Jason] learned a lot by successfully automating this meat smoker. This is just the first step in [Jason’s] smoker project. He decided to begin by hacking a cheaper charcoal-fed unit first, before setting his sights on building his own automatic pellet-fed smoker. With a charcoal smoker it’s all about managing the airflow to that hot bed of coals.
[Jason] started by making sure the bottom was sealed off from stray airflow, then he cut a hole into the charcoal pan and attached a length of steel pipe. The opposite end of the pipe has a fan. Inside the pipe there is a baffle separating the fan from the charcoal pan. The servo motor shown here controls that valve.
The pipe is how air is introduced into the smoker, with the fan and valve to control the flow rate. The more air, the higher the temperature. The hunk of pipe was left uncut and works fine but is much longer than needed; [Jason says] the pipe is perfectly cool to the touch only a foot and a half away from the smoker.
With the actuators in place he needed a feedback loop. A thermocouple installed into the lid of the smoker is monitored by an Arduino running a PID control loop. This predicts the temperature change and adjusts the baffle and fan to avoid overshooting the target temp. The last piece of hardware is a temperature probe inside the meat itself. With the regulation of the smoker’s temperature taken care of and the meat’s internal temperature being monitored, the learning (and cooking) process is well underway.
There are many, many smoker automation projects out there. Some smokers are home-made electric ones using flower pots, and some focus more on modifying off the shelf units. In a way, every PID controlled smoker is the same, yet they end up with different problems to solve during their creation. There is no better way to learn PID than putting it into practice, and this way to you get a tasty treat for your efforts.
I’m in the process of automating a smoker as well. Going to go with a pwm fan instead of a valve.
so you like big butts and you cannot lie?
https://www.youtube.com/watch?v=2T4-5YFJaos
The fan is controlled by PWM and the valve is moved in tandem with the fan duty cycle.
Heatermeter project by Captain Bryan is a lot more impressive. Should really showcase that project (again?). It’s come a long way and really gathered a lot of support from the bbq tech community as well.
If it’s pipe, it’s gotta be steel!
Begin the unnecessarily complicated smoking mechanism!
My automated smoker build controls the temperature of an offset smoker by automatically raising and lowering the firebox lid with a thermocouple in the cook chamber for feedback. It saves me from having to watch the process so carefully. It’s a stick burner.
Smoked Mullet——-an old refrigerator in the back yard works great, lots of shelves. A trench several feet away covered with a board feeds the smoke. Button wood works good. Great for gator also. The wife will never get used to it
That’s a rig I’d love to see documented!
Mine is very similar to the commercial systems, fan on/off control with duty cycle adjustment. TC on grill(!) and arduino or process controller (omega dpi). Arduino is better because of custom logging and extra channels (meat core temp, etc) .
Btw don’t use steel pipe/tube with zinc coating (galvanized) if it get’s really hot starts to emit some nasty stuff.
The link to that project now goes to a Japanese porn site… :(