I want to automate the air opening of my wood stove.
Its a linear opening of 3 inches long.
I was wondering if someone could help me on how I could do the mecanical part.
The area can go up to 500F (when I forget to close enough the air opening).
I have been thinking about this today and I was wondering if a servo with a arm attached that would be pulling/pushing a fine metal rod or a flexible cable (like the one for brakes on bikes) could do the job…
For your other questions, it will be automated. I want to buy a Ethernet Arduino for this. There will be a sensor for the wood stove and a sensor for the ambiant. I’m searching for those sensor currently, one that could do 0-1000F would be great.
The system would adjust slowly the air opening more or less to keep a designated reference temp. So I need to know the position of the servo.
Thanks for your help for the brainstorming of my project!!
I dont think there is much force required to slide the opening (horizontal). I dont have a way to mesure this…
I would like to have a linear actuator, but I find them expensive… This is why I want to use a servo. Maybe you have model to sugest?
For the heat, as soon as you leave the wood stove surface its ambiant temperature. I can build a support that will place the servo away for the heat.
Thanks
Here is a picture of a wood stove with the same air opening. Its a metal plate that slide horizontaly. It slide with one finger but it has some resistance.
Do you think that a servo will be capable to open and close the vent?
Yeah its a way to solve this. Maybe more like the throttle of a car engine. So this way I can install a tube that will place the servo away from the heat and he will control the air flow.
I can build a 2in tube and put a little plate inside of it that will be controlled by the servo. Will the servo be capable to hold position when there will be an air draft?
Ok, I’m seeing the system. I will need to build this from scratch. I have done some research and I have not found any already build device. I will need a servo to control the angle of the opening. I have included a drawing of the system I will build. A half circle that will rotate.
Can you suggest me a servo that will do the job? I will also need a Ethernet Arduino. Can you make the proper recommendation for connecting these devices together. I’m new to Arduino but good with programming.
One more thing I need, a thermocouple or a thermistor that can read temperature up to 500F. It will be plugged with the Ethernet Arduino.
Thanks!
How hot is the area around the opening? If it’s quite hot, you should not put a linear actuator close by. Instead, put the linear actuator a distance away, connected to the opening by a rigid (hollow to be lightweight) metal rod. You can also consider a pulley system.
How would you like to control the motion? Remotely? Automated? If automated, what sensors would you use (i.e. what are the criteria for opening the more or less) and are you prepared to program a microcontroller? Does the exact position matter or it’s just fully open and fully closed?
Can you get an idea of how much force is required to move the door? Is it moved horizontally or opened upward? If it’s horizontal and very easily moved, then you might consider a servo installed at a distance away from the door (remember, most are just normal hobby servos intended to be used in models - not subjected to high temperatures above 30C). The ideal would be a linear actuator installed at a distance away from the door so it’s not subjected to the heat.
Can you take a photo of the door? Without an idea of the force required, it’s hard to suggest a specific servo. If you don’t have a way of quantifying it, can you push it easily with one finger? Do you need both hands? Could a mouse move it? 
The photo helps a lot. Those are certainly meant to be opened by a human and there is no built-in mechanism to make opening it easy - it’s metal to metal contact, and not even smooth for that matter. A servo (unless it’s a big one) will have issues. The other issue is how to mount the servo so that the motion can fully open and fully close the vent. A linear actuator seems to be the best solution still.
A few additional ideas - rather than the current “door” which slides left and right, could you create a new metal plate which rotates (much like the air vents in a car)? This would still have the desired effect of letting more or less air pass through, and a servo could easily rotate the part. Another option would be to create a door on a hinge so the servo could raise and lower it.
Try a 645MG servo(you can connect this directly to the Arduino board provided the current is not too high). We only offer the Phidgets K-Type Thermocouple which can reach the temperature you describe, but the suggested board is the Phidgets Temperature sensor board, which is USB - it would be up to you to create the proper code and circuit to use this sensor with the Arduino.
If you used a rotational door the air draft will be parallel to the rotational axis and as such will not create much force to make it rotate. A servo should be able to hold such a force indeed.