Parent Category: Big Blue Saw Blog
Created: Friday, 11 March 2016 22:54
Written by Simon Arthur
When we last took a look at the lighting situation here at the Big Blue Saw secret underground base, I had created some translucent P95 acrylic lighting diffusers to cover up our bare CFL bulbs. They were nice, but I had a burning desire to make something even better. As I noted before, I really liked the way the light caught the edges of the lighting diffuser. So of course, I wanted more edges. The original design was a bit difficult to install because it was hard to keep the hooks straight with only one hole per hook in the diffuser, so there was room for improvement there as well.
Adding more edges meant expanding into the 3rd dimension. I had in my head Big Blue Saw themed diffusers like before, but stacked and wrapping completely around the bulb to keep it hidden from more angles. I realized that by using a slot technique, I could assemble the flat laser cut diffusers into a multi layered shade.
The next step was to fire up Inkscape and get started. I experimented with several designs until I came up with one I liked. Below are the risers. They each contain 6 evenly spaced slots to hold the saw-shaped diffusers. Each has two holes on the top to hold the mounting hardware which will keep the whole fixture in place. The risers are about 9.6 inches in total length, with approximately 6.3 inches between the top and bottom saw pieces.
The next step was to design the 6 Big Blue Saw themed lighting diffusers. I used the same outer shape as on the previous diffuser project, but with a center hole in each one 6.7 inches in diameter to make room for the light bulb. These diffusers ranged from about 9.8 inches in diameter up to about 15.8 inches in diameter. The plan was to put the smallest on the bottom and the largest on the top, that way every piece would be visible since you're typically looking at this from underneath (thanks to Julie Simancek for pointing that out).
The bottom piece was different from the rest, though. It needed to be solid on the bottom to completely hide the bulb. It also needed to keep the risers in alignment. I created a set of slots on the bottom piece running in a circle to keep the risers in alignment while still obscuring the bulb. The slots are also decorative and show more of the edge effect from the lighting.
The whole design was then laser cut from 3 mm thick P95 acrylic.
Assembling the shade was a lot more work than I thought it would be. I actually cracked one of the risers on my first attempt. I eventually figured out that the saw diffuser pieces had to be supported while the vertical risers were slid into place, otherwise too much stress would be placed on the risers. So I slowly built up the shade from the bottom, supporting the diffusers with some miscellaneous parts from around the shop, and clipping the first riser in place to each diffuser.
Having run out of small waterjet cut parts, I switched to Keva planks for my scaffolding. Below is the finished scaffolding with the riser clipped into all 6 diffusers.
If I did this again, I would add slots to the saw pieces to help keep them in alignment while the structure was assembled. I'd also consider laser cutting some stands which could support the whole structure while I assembled the shade.
With the scaffolding and the first riser in place, I slid the risers in and squared up the whole assembly. The finished weight was just over 2.5 pounds
Now the piece was ready to install. I made a few clips from copper wire and ran them through the holes at the tops of the risers. This allowed me to attach the whole shade to the lighting fixture.
Do you have any ideas for improving this design? Let me know in the comments section.