In my prior blogs,
I discussed my initial design thoughts and detailed design for my smart lighting project.
Today I will be presenting some of my mechanical thoughts and designs for my project. My thoughts for the lighting element for this design is that I wanted a self contained, removable and weather proof enclosure that would be centered in the wood and glass frame. With this in mind, I decided on using a Clear Acrylic Tube, OD 2" x 1 3/4" ID with a 1/8" wall and a pair of 2" Black Vinyl Caps. I was able to order these items online through TAP Plastics (https://www.tapplastics.com/ ) along with a selection of sample size, Acrylic sheets in a variety of tints and textures that I intend to use a diffuser to normalize the lighting source in the hope of creating a fairly homogeneous light intensity.
To create some brackets and holders for the PCB and the diffusers, I needed refresh my CAD skills in Fusion 360 (always a challenge). First, here is an overview of the placement of key items in my design (superimposed on the PCB layout):
The orange circles show the location of the four LEDs (two on each side of the PCBs), while the gray boxes are the rough placements of the four diffuser panels (centered over each of the LEDs). The diffuser panels are held in place by brackets that space the panels about 1/2" above the LEDs. These diffuser panels are 1" x 1.7" and are 1/8" thick. The brackets (4 each of two mirror image designs) are held in place with screws through the 4 corner mounting holes. Here are images of the brackets:
The upper surfaces of the the brackets have two notches that are intended to capture the corners of the diffuser panels. A pair of brackets are mounted (normal and mirrored) at each mounting hole. The photos show a pair of brackets (hot off the printer) installed on prior lighting system PCB (not reflecting the proper placement of the diffuser panel relative to the LEDs).
To center the PCBs within the Acrylic tubes, an end cap was designed to fit inside the tube and to hold the PCB edge. Here is the image of the the end cap bracket:
Here is an image of a end cap installed in the Acrylic tube (earlier version on the end cap and a fake PCB) :
I am still waiting on my PCBs (running late in the mail, hopefully not lost like my last order), so I can't add actual assemblies at this time, but I should be able to show these in the near future.
Thanks for following along on the project series.
Update 8/21: This morning I installed the light box frames (and one pane of glass) into the opening along side the stairs. Here is a quick picture (front/back) of the installed light box:
Note: auto exposure really pushed the wood color in the first image to a much browner shade that actual, which is much closer to the second image (darn, I kind of like the brown coloration). Also, measure twice, 3D print once! I noticed today that my light boxes are a bit smaller than I had planned, I will need to adjust 3D printed PCB end clip/holders as I need to shrink the lighting elements a to match the correct dimensions.
Yeah! My PCBs arrived yesterday evening. I am building up the first PCB so I can test the solar-based charging and some light output levels.