Box light

16 Mar 2017

I'm very late with this post because instead of doing a quick review of the Nintendo Switch, as I originally intended, I decided to build a light instead and then took a few days to get the images sorted out, which was enough time for me to get started on another project and forget about this one. Luckily that project is almost done so I might manage to get two updates out this week, depending on how tired I am after the Flyball tournament on Saturday.

This came about because I was thinking about taking some pictures of the Switch early Saturday morning, but the sky was overcast and the light wasn’t great. So I thought that I probably had enough bits lying around to build a light, which would be a fun weekend project.

The design is pretty simple, a frame made of 18mm plywood, a fibre board back, a roll of cheap LED tape, 18W LED power supply and some assorted electrical stuff.

So I started off with the wood, marked it out to the correct length and cut it on the table saw. I decided to cut the mitres next as I wasn’t sure if I’d get tear-out if I did this after cutting the rabbets. After that I set the fence and cut the rabbet for the plastic diffuser to go in. To cut the wider rabbet I did the first cut, then using a offcut to test, adjusted the fence to get the right width before running all the pieces through to expand them to full width.

After sticking it together I left it to set while I cut the back board roughly to shape and gave it a few coats of white emulsion to reflect more light. Once the paint had dried I started laying out the LED tape. After previous tests with the LED tape, and having one wire ping off as you try to solder the next onto it, I decided to stagger the main busses. It’s a little more soldering, but a much less annoying job.

Box Light : Wiring

After doing this I had to wait till the next day for the glue to set hard on the frame.

Obviously things had been going too well so something had to go wrong and it happened when I tried to put the back board into the frame for the first time. I got the board about halfway in when one of the mitres split, which is probably because I’d forgotten to cut down the board before trying (I only cut it roughly to size before painting). While this isn’t really the fault of the mitre, it did make me think that I should reenforce them a bit, so after gluing it back together I decided to put some splines in after it had a few hours to set. While I was waiting for this I measure the length of the removable side and cut the back board down so I didn’t try and destroy the frame again.

Box Light : Frame construction

After that mistake, final assembly went pretty smoothly. Before I fixed on the final side I checked that everything was working and found that I’d managed to pull one of the bus wires loose while I was getting it together. It didn’t take long to solder it back in place but I’m glad I checked before adding the bottom side of the frame. Once that was fixed I added some screws to hold the bottom on and the light was done.

As the light is pretty large it casts very soft shadows so should be good for getting natural looking shots of things. Using a cheap reflector on the opposite side of the object to the light would probably remove most of the shadows completely, but I haven’t given that a try yet.

Box Light : Finished