Audrey the Auto-Doser

My brewery gadgets typically end up with names, for convenience. The carb-bot became Carl. The peristaltic yeast pump became Perry. This way, in an actual work situation one can say, “Hey, throw Perry on FV4 and see if you can get 10 lbs. of clean slurry.” I have determined that this time around, I am building Audrey.

Since the last post I’ve whipped the code into a semblance of functionality, enough to start shaking it down on the actual hardware, which means time to bolt this stuff together.

The plastic NEMA 4 enclosure I selected for Audrey is probably a little bigger than strictly necessary, but that’s better than too small. Besides, I might think of more stuff to add as I go along.

A trick I’ve used for years for drilling and cutting mounting holes in panels and boxes is to make a template drawing in CAD, and print it at 1:1. This works “good enough for government work.” (Also, General Motors.)

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After what seemed at the outset to be a small matter of drilling, cutting, and assembly, but turned out to be several hours of exactly the sort of activity I had hoped to be recovering from over the weekend, I got all the pieces bolted together. Like so:

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We got our pushbuttons, on/off selector switch, and LCD display on the front, with 4 peristaltic dosing pumps up the side. Inside, clockwise from the blue Arduino PCB we have a DC-DC converter (24V to 5V) 24 VDC 200W power supply, and four stepper motor controllers. Wiring it up will have to wait; I need to ice my tired hands.