The FrankenFridge: Mini-fridge fermentation chamber sized for a 1/2 bbl keg

So, I had converted a mini-fridge to a fermentation chamber controlled by an arduino with a Respberry Pi using the BrewPi controller software.  It was working great, and all I wanted to do was enlarge the chamber, since it would fit my 6 gallon glass carboy but I wanted to be able to ferment 10-gallon batches in my new sanke keg.  So I had this great idea that involved cutting a hole in the top of my existing chamber and extending it....

Long story short, in the process of attempting this great idea I managed to cut through the condenser lines of the first mini-fridge, destroying its refrig unit.

Back to the drawing board.  But I realized that the reason a standard mini-fridge can't fit a sanke keg is only because it uses a bunch of space in the bottom rear for the compressor.  If the compressor were moved outside that space, there'd be plenty of room...

Thus was born the idea of FrankenFridge.  I had an older, smaller, mini-fridge, made in the days when things were built to be fixed- thus also built to be taken apart intact.  This would be the donor unit for refrigeration.  I had a second modern mini-fridge from the dump, whos compressor had presumably given out.

Step 1: remove the floor and bottom rear of the "skeleton" fridge:

Step 2: add insulation and flooring to the areas where material has been removed:

 Here you can see the interior floor- this covers the blue-foam floor and is intended to be robust to fermenters being slid over it...  At least a little more robust than the bluefoam itself...  you can also see some spray-expanding-foam that sealed the gaps.

 I also went though and sealed up everything with duct tape, just to keep it from looking too nice...  Note here that I'd needed to remove the ledges on which the fridge shelves sat, in order to make enough width for the sanke keg fermenter...

 Here are the innards of the donor fridge- compressor, cooling plate (which makes the freezer section of most mini-fridges), and condenser coils. 

 And the marks for where to cut out the back of the new fridge to insert the cooling (evaporator) plate.  I inserted the plate, placed the compressor right on top (bolted down) and mounted the condenser coils to the back.

Inside, I've got both the controller for the cooling unit, and for heating I use a medical heating pad.  Both heating pad and fridge compressor are wired into Solid State Relays (SSRs) that are controlled by the BrewPi.  

 The outside of the finished product- note the compressor sitting on top, along with the wiring and controllers for the brewpi.

And in the end, it fits my Sanke keg fermenter almost perfectly.  Note that the shelves from the inside of the door had to go as well.  AFFIRMATION- Yes, this was once a commercial keg, but it was freeze-damaged, taken out of commercial service, and I acquired it completely legitimately!  I promise!