Small Electronic Experiment Station

I do a lot of electronic experimentation, with Arduino and discrete components, but I do a lot of other making also, so I'm always running out of space for my current projects. Sometimes my workbench is literally buried inches deep in projects!

Breadboarded circuits are not noted for robustness, so knocking around and having stuff spilled on them is a less than optimal situation.

Spurred by the success of my small wood toolbox, I decided to do something about it! (Of course, this in itself is another project adding to the overall clutter...)

Since I don't do big electronic projects, this only needed to be big enough to hold a breadboard, an Arduino, and a few other parts. I wanted it battery powered so I wouldn't have to take up space with a bench supply every time I wanted to test a simple circuit. I also wanted a protective lid for storage, and a drawer to hold batteries and a few loose parts. The overall dimensions of this station are 8" wide, 6" deep, and about 1.75" tall, without lid.

The only thing really needed for this project is a couple of square feet of 1/8" plywood and some white or wood glue.

To make it as presented, you'll also need:

• Switch (Almost any switch will do as long as it fits)
• Battery holder (I used an 8 AA holder)
• 9V battery clip
• Some sort of small connector to mate the battery wires with the power panel wires
• Binding posts (red and black, Radio Shack)
• Adjustable voltage regulator board with voltmeter
• Arduino Uno board or clone
• Solderless breadboard, 300 tie points
• A few inches of 1/8" wood dowel
• 2 Suitcase-style latches
• 16 #2 X 1/4" wood screws (Hopefully, they come with the latches)
• Wire
• Solder and soldering iron
• Drill and 1/16" drill bit to drill pilot holes
• Possibly a 1/8" drill bit for more mounting holes
• Screwdriver
• A small amount of ambition

The pattern provided in the next step is for laser cutting, but it wouldn't be hard to make this with a saw; just ignore the tabs and make simpler joints. I etched the labels with the laser as well, but labels can be made many other ways. The switch cutouts are for the switch I had, which you probably don't have. A mini toggle switch is a good alternate choice.

Here is the pattern for cutting the wood. There are four subassemblies: The base, drawer, lid, and power panel. The lid has one of the long sides overhanging the base. This is not an oversight; It was designed this way so that the overhang locks the drawer in place when the lid is attached.

The base has a hole in the back for the battery pack wires. There is a matching hole in the back of the drawer, and a notch in the lid for the wiring to the power panel.

The file is in pdf format, and can be edited with Inkscape. Also there is a hole pattern template for the Arduino Uno for your own design uses. The .svg file is in zipped format.

As mentioned earlier, I cut this on a laser, but it can be made using conventional wood tools as well.

I did not take any pictures during assembly of the wood parts, but this is pretty straightforward.

All 4 of the sub-assemblies are simple 5-sided boxes. The base parts are the ones that have a straight edge on the long sides of the large pieces, a straight edge on the short side of the small pieces, and a piece with notches all the way around and one hole; This piece is the back. If something doesn't fit, it's the wrong part!

Glue the 5 sides of the base together, making sure the side with the labels is on top, and the hole in the back is on the lower left when viewed from the front.

I drilled some extra holes for mounting the adjustable regulator, and mounted the breadboard with the supplied double-stick tape.

The drawer is also a 5-sided box, slightly smaller than the base and shallower than the lid. Assemble the drawer with the round hole in the back to the lower left when viewed from the front, just like the base. The two holes should match when the drawer is slid into the base. The rectangular hole is on the front of the drawer for the drawer pull. Assemble the drawer pull by gluing the cross-shaped part into the hole in the oval part, then glue into the hole in the drawer front.

I installed a couple of partitions in my drawer which are not in the cutting layout. These help keep the battery pack under control.

The lid is the last large 5-sided box. One of the long sides of the lid is about 3/8" larger on the long side than the other. This will be the front of the lid and hang over the drawer to keep it closed when the lid is in place. The notch in the back of the lid should be on the left when viewed from the front.

The power panel is still another 5-sided box... but it's the last one, I promise! the long sides have six tabs that align with the six rectangular holes in the base. I mounted the binding posts and switch and wired it all up as shown. The leads from the 9-volt battery connector are fed through the hole in the back of the drawer and the base, then spliced to longer wires with a small battery connector on the end. I made sure the wires were long enough to pull the drawer completely out. I scavenged this connector pair from a toy battery pack.

You can leave this project unfinished, but I don't like the feel of raw wood, so I sanded it and put one coat of polyurethane on it, the sanded it again with 220 grit sandpaper to give it more of a finished appearance.

I wanted the lid to be completely removable to get it out of the way; It can also be used as an additional parts tray when removed. To do this, I decided not to put hinges on it, but one suitcase-style latch on each side.

Mount the latches centered on each short side. Mount the small part first, on the base, then latch the latch and mount the top part. Drill 1/16" pilot holes and screw the latches on with 1/4" small wood screws.

If the screws protrude into the inside of the base, they will interfere with the drawer. I had a small problem with that, so I just filed and sanded the screw tips on the inside until the drawer fitted properly again.

The small wood "washers" in the parts file are spacers to allow the Arduino to be mounted but removable. The washers are glued to the dowels allowing about 1/8" to protrude from the bottom, and the long ends are pressed into the Arduino mounting holes. The dowels should be snug, but they may need a little sanding to make them fit. The Arduino can then be pressed into the holes in the base.

I originally wanted to mount the power regulator with double-stick tape, but decided to mount it the same way as the Arduino. I positioned the regulator and drilled one 1/8" hole using it's mounting holes as a guide. Before drilling the second hole I inserted a dowel in the first hole, then inserted another dowel in the second hole before drilling the other two. This is the best way to get all holes correctly positioned.

I stuck down the breadboard with double-stick tape.

The capacitor board from the first step was not attached, since it will not always be needed.

The battery wires were routed out the rear of the base through the hole and connected to the pigtail from the power panel.

This station has the same footprint as my small wood toolbox, so I can stack the toolbox on top of it when not in use.

Now that I have a nice experiment station, I have to clean off my workbench so I have room to use it!