This post will go into detail on how I assembled the individual acrylic shelves for my element display, including where I ordered the plastic and the process of attaching 240 shelf pins to the 120 shelves. To read about the project as a whole, see the introductory post.
I designed the element display to have individual acrylic shelves for each element on the periodic table. The entire display had to fit in an area of my house that the realtor called the “office nook.” The size of this space governed the dimensions of the overall display. I won’t bore you with the details (because it was quite involved!), but my calculations led me to a per shelf size of 3” square as being the largest I could accommodate. Each one is ¼” thick.
After a lot of searching around for a supplier, I settled on Ridout plastics (www.eplastics.com) for their great quality and reasonable price. I had used them to buy supplies for my prototype systems too, so I knew they were good. Their business model is to sell plastic in large sheets, which you pay one price for, and then you can pay extra for them to make a number of cuts to this plastic. My sales rep worked with me to find the smallest number of cuts for what I required. I ordered one large sheet (48" x 48" x 1/4") and had them cut it into as many 3”x3” pieces as possible. I ended up with 196 squares! This gave me a LOT of extra pieces at no additional cost (since you buy the sheet and pay for once for a range of cuts, and the extra cuts kept me within that range and thus didn’t alter the price). The acrylic came with a protective brown paper covering for both sides of each piece. And before you ask, no they did not pay me to say all that – I’m just giving out some positive feedback to anyone else considering ordering from them!
I also went through every piece I received and sorted them based on quality of the cut (I had enough extras where I could do this). Some cuts left crystal clear edges, which I used preferentially over those that were a little rougher and thus gave the edge a foggy look.
The individual shelves were fairly straightforward to assemble. These acrylic pieces were attached to clear plastic shelf pins, two per shelf, using Weld-On #4 (also bought from Ridout). This is a special plastic adhesive that chemically welds the two pieces together, affording a very strong and fast-setting bond. The adhesive is primarily dichloromethane, which works by dissolving the plastic. When the solvent evaporates, the plastic molecules of the two pieces intertwine and in effect become a single piece. In fact, a minor accident showed me that the shelf pins themselves will snap in half before the actual adhesive fails!
For consistency, I drilled two holes in a piece of wood at the correct distance apart and used this template to assemble every shelf. That way I could ensure the pins were always the same distance apart for every shelf, and that holes in the backboard would line up with the pins (for the most part – some holes needed to be fleshed out a bit to fit properly). While the adhesive was setting, I used some tin bars I had lying around as weights to hold things together. Here is a short video showing the process. The first half is the shelves, and the second involves the LEDs (which I will talk about in another post).
Once this process had been repeated 120 times (plus some spares that I also made), the shelves that the actual elements would sit on were ready to be “plugged in” to the backboard. Though there are only 118 elements, I have two extra shelves in the display as placeholders for the lanthanide and actinide series. Check out the following links for more info on the backboard construction, LEDs, and the LED control circuitry portions of this project!