Introduction: Arduino-Plex: Plexiglass Arduino Work Surface
I am still new to Arduino, but as I tinker I find it very difficult to keep my projects together. I use a Velleman solderless breadboard and an Arduino Mega board (I know, I made a mistake and bought a Chinese one. I have since bought an official Arduino Uno board). I do a lot of work at the kitchen table with a laptop because it is less dusty than the garage, but then everything needs to be boxed back up and put away again. Sometimes I leave my projects together, and sometimes I have to dismantle them to fit them back in a shoe box. I sometimes keep notes on a clipboard, which also worked pretty well as a movable workspace. I could stack the laptop, shoebox and the clipboard all together and move them out of the way without too much effort. I remembered I had some Plexiglas that had been waiting for a good project to come along.
Step 1: Hardware
When I build a computer for someone, I usually keep the extra screws and standoffs that come with the case and/or motherboard. Because of this, I had a bunch of different standoffs, felt washers and screws to choose from. I decided to go with the ones with the largest threads and the tallest heads.
Step 2: Plexiglass
I bought this piece of 1/4" plexiglass at Skycraft last time I was in Orlando. I didn't know what I was going to do with it, but it was a great price so I had to get it.
I used a framing square to lay out my lines on the backing sheet of the acrylic. Because the clipboard worked well, and is also roughly the same size as my laptop, I decided to use it as a template for the plexiglass. I used a jigsaw and a straight edge to cut the piece, which worked pretty well. The saw didn't melt the plastic, and there was no chipping. You just need to work slowly and make sure you hold the piece when the blade is nearly through the acrylic. Plexiglass can be brittle when you make very small cuts, so take special care in the corners.
Once the main platform was cut, I cut a handful of small square feet to mount things to the board. I didn't want the standoffs to poke through the other side, and I didn't want any holes in the underside of the platform. I drilled and tap these feet, mounted them to the Arduino board, and glued them down in place. This helped align the feet and standoffs to exactly where they need to be for the Arduino.
Step 3: Standoffs
I didn't want to weaken the board or have the screws poking out the other side of the plexiglass, so I made these square pads to screw the standoffs into. I clamped the squares in a vice, drilled holes straight through the pieces and tapped them to make threads for the standoffs. Once the holes were tapped I used a socket driver to screw the threads down into the Plexiglas.
Unfortunately, these standoffs are made of some very soft metal because a few of them broke off in the holes. You need to make sure that you tap the threads deep enough that the standoffs don't bottom out. If that happens, they will snap off in the hole and you'll have to start over.
I mounted the feet to the Arduino board and made sure they were level. Only 3 of the holes were clear to hold a screw, so I had to make a small support for the other corner that is not secured with a screw. You can use an acrylic cement if you want to special order one, but I used super glue and it worked fine. I have read that the acrylic cement makes clearer joints, but I wasn't making large joints so I didn't care.
Step 4: Finishing the Edges
Plexiglass is very easy to cut, but it gets a rough edge with almost any blade. To fix this, you need to sand down the edge and lightly heat it with a blowtorch. Don't leave the flame in one place more than a second. You need to keep the flame moving or the Plexiglas will bubble and burn. Once it's heated, the fine scratches in the edge that make it cloudy will level out and become nice and clear again.
I forgot to take pictures of this step before the boards were mounted on the Plexiglass. You probably don't want anything mounted to the board until after the edges are melted smooth.
Step 5: Assembly
Once I had the standoffs mounted on the Arduino board, I moved the parts around to see where they should be mounted. The Velleman breadboards have little dovetailed brackets that hold them together. I left the bus boards in between the breadboards, but if I were doing this again I would have moved them to the outside. I think its more useful to have shorter gaps between the vertical traces than to have the extra bus lines in the middle of the board.
Step 6: More Arduino?
Originally, I bought an "Arduino" Mega 1280 on Ebay. I didn't realize I was buying a counterfeit board, but the price was terrific and I should have known. I wanted the mega because it had more ports and more memory, so I assumed that meant I could do more with it than the other boards. Unfortunately, I found that I couldn't use a lot of the standard shields that are available. I bought a PoE (Power over Ethernet) shield from Sparkfun that didn't specifically say what boards it worked with, and discovered that it would not work with the Mega boards. The digital pins on other boards are combined with other pins, but on the Mega, the digital pins moved to the end of the board. I tried a workaround, but had no luck so I went ahead and bought an Uno board.
The mounting holes are a bit different on this board than they are on the longer Mega board. I made some more standoffs for the Uno and mounted it to the Plexiglas alongside the Mega.