I justed browsed some of the great automation projects here and thought I would post my own. Maybe provide some inspiration. You don't need that much money to do it.
It all started when I had to run out during a boil and left a friend in charge of the last hop addition and turning the boiler off. Well he only switched one element off so the boil ran 30mins over and I ended up with one very bitter Schwarzbier.
So the brewbot was conceived. The idea was:
* Night before: crack the grain & put it in brewbot's mash tun.
* Weigh hop additions and add to brew bot
* Punch in desired final volume and mash/boil times.
* Punch in start time
* Wake up in the morning to a finished brew and run it into a cube for no chill.
Some other requirements:
* reasonably portable (I don't own the house)
* self contained & reliable: no PC hardware
* all electric (i.e. not LPG for heat)
* tight budget - recycle old junk
So what did I end up with?
Initially something like this:
But eventually I wanted to move to all stainless fittings so worked out I could save at least one valve if I went to gravity fed from the HLT:
Contains and AVR Atmega-128 board for the CPU. Some signal conditioning hardware, some TRIACs and relays.
DS1820s for temp probes.
The automated valves were interesting. I decided to use some windscreen wiper motors that I had on hand from another project (restoring a 1963 Morris Mini Panel Van) to actuate some gate valves:
The interesting part of course is how to know when the valve has reached the end of its travel. Quite simple, the CPU monitors the current drain of the windscreen wiper motor. When it hits the stopper the motor stalls and the current draw goes up.
The hop dropper was pretty straight forward. Just another windscreen wiper motor and a microswitch:
Small plastic cups with the bottoms removed sit in the holes and slide around pushing whatever hops with them.
Also since it sits over the boiler and cops a heap of steam, it all sits in a plastic case that is pressurised with a computer fan to stop steam getting in and making the hops swell up.
I actually haven't touched the brewbot for a year. But when I get back to it the TODO list is:
* move to a Stainless Steel mash tun
* add a mash mixer
* mount the mill
* better automated cleaning
* better HLT level sensing
* a HLT stirrer