The Airhead
If you own an original Still Spirits Air Still or one of the many clones, you are very well aware of the problem they have where the distillate constantly starts and stops. This is caused by the Bang-Bang temperature controller that they all use. They send full power to the heating element until a temperature is reached and then it cuts-out until it drops back to the cut-in temperature.
The distillate flow is directly proportional to the heating element power turning on and off. This works great for space heaters and electric hot plates, but is absolutely horrible for distillation. What makes it worse is that this will cause foul flavors in your distillate and can also lead to scorching.
The Airhead solves this problem by using a solid state relay and a custom low speed pulse width modulator to pulse the power to the heating element. This pulsing maintains a constant upward thermal velocity that prevents scorching conditions by forcing suspended solids to stay afloat. It also helps push ethanol upward out of the wash. The still just works a whole lot better!
The PWM is driven by a custom-coded PI controller designed specifically for ethanol distillation. However, if you ever want PID control, you can switch the controller over to Micro Boilermaker mode at the press of a button. This means that you can actually ferment and distill in the same tabletop appliance!
The Airhead features three operating modes. (1) Constant Power, (2) Constant Temperature, and (3) Timed Run with user selectable starting and ending temperature. It’s not exactly a smart still controller, but it sure does make an Air Still a whole lot smarter than it was when it came out of the box!
The Airhead is available as a kit that you install yourself, or you may optionally drop-ship an Air Still (or clone) to me to have it installed and tested before it is shipped on to you. I have provided both installation and usage videos on YouTube to make things as easy as possible. What’s more is that when firmware updates are released, anybody can update an Airhead over WiFi!
Additional Product Notes
Since all cases are 3D printed, you have your choice of Black or White, this will be confirmed after the order is received. Other colors may be available upon request, but will require an additional fee and delay time to ship. Cases are 3D printed using PETG filament to make them heat resistant, without emitting the foul odor that comes along with ABS.
Ordering Information
Airhead Turn-Key Kit : $140 + USPS Ground Advantage Shipping
Airhead Installation Service : $200 (includes shipping and insurance)
Refer to the GitHub page for further instructions, to report any and all bugs, and to make suggestions for future enhancements.
Open Source Declaration
I have made this product an open source project on GitHub since day one. This includes all source code, diagrams, and 3D models.
You are more than welcome to build your own from scratch, make a fork of the project and improve upon it, anything you wish up to and including selling your own version. Simply honor the GPL.