The South Africa trip in the end of 2013 was basically what started all of this as mentioned earlier. The mbira was a reason to build an amplifier and the amplifier was the reason to build an UV exposure box. Buying the circuit boards would have been a lot cheaper but far from as much fun.
The material used is the same wooden board as the biltong box was made from. This was probably not the best material to build it from and it might very well happen that it will be rebuilt in MDF or something similar in the future. There are tons of instructions on how to do these online but whatever, let’s get started!
The picture shows an initial sketch of what the box will look like. There are two chambers, one to the left with two flourescent UV lights in it and one to the right where all the starters and the reactor will go. On the lid there’s a foamy material pressing down against the glass over the lights.
The UV chamber has been designed to be as small as possible. The lights should be separated by at least 4.5 cm and it should be at least the same distance from the lights to the glass. This and the 12 mm thing boards gives the dimensions below. Yep, metric system again, it’s the only thing that makes sense really.
A: Front + back (27×9.5 cm)
B: 2 sides (31×9.5 cm)
C: Bottom (24.6×31 cm)
D: Divider (31×8.3 cm)
E: Lid (33.4×27 cm)
Glass (17.3×31.5 cm)
2 flourescent UV lights for circuit board etching
4 flourescent light holders
2 holders for flourescent light starters
1 flourescent light reactor
Reflective material (i.e. tin foil)
Some kind of foamy material
A bunch of tools
Building the Box
If you have a wood router, use it! Or even go buy one. Seriously. It’s worth it! Without it you have to improvise, like with one of these Japanese hand saws. You should definitely get one of those anyway, they’re great!
The black spots doesn’t serve any purpose, it was just to try the paint.
The inside of the UV chamber should be covered in a reflective material. Tin foil can be used but in this case a sound dampening material covered with a heat reflecting aluminum film was used. The film could be removed and cut to fit in the UV chamber. It was simply attached using double-sided tape under the glass on both sides. The holders for the lights keep it in place as well.
The sound dampening material (2 cm thick foamy material) covered with the aluminum foil will cover the inside of the lid. The glass is about 1 cm down into the box so that when the lid is closed it is compressed and presses the copper clad board and the pattern against it.
And here’s the final result. Oh, right, there’s a lock to keep the lid and the foamy sound proofing material pressed down against the glass. The back of it is adhesive so it was just to cut it to the right size, put it on the glass with the adhesive side up and close the lid for it to end up in the right place.