For the last week I’ve been at it working on my fermentation chamber. It’s taken longer than I anticipated, a lot of the issues cropped up in my assembly method. I think if I were to do this again, I would do a few changes to the actual wood frame of the chamber.
One thing I should have mentioned with this project is the following.
If you’re not familiar working with high voltage electricity or don’t have experience, do not attempt this project. This project deals with high voltage electricity and there is a potential for electrocution if you don’t know what you’re doing.
Consult an expert or training sources for working safely with high voltage electricity if you’re unfamiliar with safe practices.
Building the Box
The last couple of posts were about getting some of the materials ready together for the setup. Now we start building! To see the general design, go to the previous post to see a CAD model.
First thing I did was remove the door from the fridge and give the inside a good clean. It took a little elbow grease, but it’s looking good to go.
The next step was to start making the cuts for the overall chamber. I had to make a few adjustments to my design in order to make sure I could make all the cuts on one sheet of plywood. I made a few mistakes, I’ve detailed them below.
After making the cuts, piece by piece I put the box together. I attached the side to the bottom of the base to try and test fit everything before I cut the foam out. See the design issues section for issues I ran into. I used some MDF board I had for the front (I didn’t have enough Plywood)
The last remaining piece of the enclosure was cutting the door and getting the hinges put on. I had to follow the same procedure I did for the back side, lying the fridge on it side making sure the top of the sheet was aligned with the top of the fridge. I made sure the door was wide enough to allow for a carboy to fit inside.
I cut the door to have the edge slightly overlap the side of the fridge. I thought a lot about the best way to cut the door as I wanted to ensure that when I closed the door I got a good seal with the side of the fridge and the foam I put on the inside of the door. I still have to cut these pieces, the edges on the doors will be the two edges that aren’t fully taped and sealed.
Foam Cutting Time
Once I had my plywood sections cut, I wanted to try and get my foam sections cut before I installed the front and made a door. I have 1 1/2″ pink foam board for the inside insulation.
I quickly realized that cutting 1 1/2″ foam board with an exacto knife isn’t the easiest thing. The solution: a foam cutter with a hot knife. An Amazon purchase and 2 days later, I had a hot knife.
I cut the bottom sheet a little small, so I’ll need to cut a thin piece to fill in the gaps, the gap to where the door will sit is too wide to just seal it with caulk.
After the side pieces were cut and checked for fit, it was time to start the wiring process.
Preparing the Wiring Box
In my past entry, I was a schematic that detailed how to connect the fridge and the heating lamp to the Arduino and Raspberry Pi. Since I wanted to minimize the number of holes going in and out of the box, I cut out a section for the outlet that would power the fridge and heating lamp.
I wanted to check and see that the wiring was at least functioning before I put everything in place. I did a test trial to see if the fridge would come on when the software requested power.
I really just wanted to see if the software was registering all the components and if the temperatures were returning temperatures. I plan to go into much more detail as to software installation and issues I ran into along the way. I made a bit of a switch as to the original plan with using brewpi, more will be detailed when I get a better chance to detail the software installation and setup.
In my next post I’ll have a few more photos as to organizing everything inside the project box.
One of the main issues I had with my design was the fact that I was planning on only using one 4′ x 8′ plywood sheet for the exterior of the chamber. Below were the cut dimensions of the exterior of the box.
I had to modify the height of the 2 side pieces to try and make it all fit on one sheet. What this meant was that the height of the exterior didn’t come all the way to the bottom base.
This was a huge pain in checking the fit and alignment for the top of the refrigerator. I had to lean the whole assembly on the side to make sure I got the side sheets aligned with the top of the refrigerator. There’s about a 1″ gap from the bottom of the base to the side sheet.
In the future, I really should make sure I make the sides are long enough to reach the bottom. Assembly would be way easier. This might mean buying more than one sheet of plywood.
Another issue I ran into is I forgot to include cuts for the front!! I got all my pieces cut, only to realize there was a big gaping hole in the front of the chamber. I was hoping I could use the remaining parts of the plywood to piece together the front, however I didn’t have enough sheet. Luckily, I had some extra MDF I used for the front.
Issue #3: When I built the base, the width was slightly too small. So when I did my trial fits of the sides, the plywood bowed outwards, meaning the top didn’t exactly line up as I’d hoped. I had hoped I could use some liquid nails to keep the plywood aligned to the side of the fridge, however this turned out to be a poor decision. Even after clamping, it still bowed outward.
I’ll put some L-brackets in on the inside of the walls to try and pull the side and top together. From a functional perspective, I don’t think it will be a huge issue because I’m putting foam board, caulking, and aluminum tape on the inside, so any crevices will be sealed. Once it’s all put together, I may add a rim around the edge to try and make it look a little nicer, since right now since the sides may not perfectly align.
Issue #4: When I went to install the door locks, I realized the screws for installing the locks were too long, as they are longer than the width of the plywood. The edge of my door slightly overlaps the side of the fridge, hence I would have to thread the screws through the side of the fridge. Bad news!
The action I used instead was to use superglue versus screws to hold the locks in place. I recognize this is a bit of a redneck approach, but it worked pretty well!
The majority of the construction is over with the exception of having to cut the foam to size and fasten everything together. There’s going to be a lot of little finishing tasks that will likely take longer than I anticipate, but I’d like it to look decent rather than a big unfinished wooden box.
Below is what’s left:
- Finish cutting the interior foam
- Wiring and Sealing the inside of the chamber
- Organizing the wiring box
- Software installation and configuration
- Finish and Painting
- Lessons learned and first brew trial!
Hopefully it won’t be too painful putting it all together, but I’m making good headway.
Thanks for reading!