I have two small electric top loading kilns. During firing I normally leave open some of the venting peep holes to allow fumes and moisture to escape from the kiln,
So I decided it would be better if I could automate the top peep hole bung to stay open until a desired temperature is reached then the venting hole automatically closes
This project consists aluminium frame ,DC motor, programmer controller and thermocouple
I used a small 12v dc motor which has a gear mechanism which slows the speed of the motor ratio down to 2 revolutions a minute . A small cog and a fibreglass belt connects to the main shaft.
The main shaft as a metal gear sprocket this allows a chain to go up and down based on the rotation of the motor and cam. On the bottom of the chain is a damper heat shield this also keeps the heat away from the chain mechanism there is also heat resistant silicon tubing on the metal shaft this helps to deflect heat from the main shaft. the box surrounding the motor is also a heat shield to deflect any heat away from the motor mechanism
The shaft is held in place by bearings which are bolted to a aluminium frame. on the end of the shaft is a cam which can be adjusted to switch off the rotation of the motor
This automatic damper as a temperature control unit with its own thermocouple which makes it fully portable,
Setting up is very easy I positioned the automatic damper on top of the Kiln . I put in the thermocouple into one of the peep holes , I then position the chain so the damper is away from the top hole . Then I set the temperature on the controller to drop the damp down when it reaches 500° ( any temperature can be set on the control)
There is a manual override this consists of a toggle switch and a green push button. The toggle switch is used to select which direction the damper override is going to be used
The damper itself is made from a ceramic tile which is connected to a small kiln prop which is the chain mounted inside
