Introduction: Powered Electronics Breadboard
This was basically a starter project for doing additional projects and largely uses spare materials I already had on hand when possible. Obviously you can simply buy a powered electronics prototyping breadboard, or just link a desktop power supply to an unpowered breadboard, but I wanted an all-in-one solution that provided some basic storage and allowed for future modification. There were some bells and whistles that could have been added such as a power switch, a power on LED indicator, a built in potentiometer, etc., but I didn't bother with them; however, these wouldn't be hard to add if you want them. Also, you could clearly customize and substitute materials at your discretion based on what you have on hand.
This project can be done with a select few tools, such as a drill, saw, utility knife, wrench, and screwdriver. My tools list is longer and contains a variety of items that I did use because they were available; however, they weren't strictly necessary. Be sure to use appropriate personal protective equipment such as safety glasses, ear plugs, gloves, dust mask, face shield, aprons, steel-toed boots, and so on, as necessary. I personally used safety glasses, ear plugs, gloves, and a dust mask for this project.
- Breadboard (Specifically this breadboard)
- Old Dell PC Power Supply - Note: This does not follow the standard ATX wiring pin out
- Plywood - I had this leftover from repairing a dining room chair bottom/pad
- Wood 1x1 - enough length for corner supports; I had this leftover from an old sign post
- Sheet Metal Screws (x4) - leftovers from a previous house project
- Hex head screws (x20) - salvaged from an old wood console CRT TV
- Screws with attached washer - from my miscellaneous/salvaged screws drawer
- Bolts for attaching the power supply (x4) - standard PC case diameter and thread pitch, but the length needs to be much longer to go through the plywood and into the power supply unit (PSU)
- Hinges (x2) with small screws (x4) - leftovers from a previous project
- Right Angle Bracket (x1) with small screw (x1) - used as a lid prop
- Miscellaneous wire - for connecting the breadboard to the PSU
- Super glue [optional] - used for locking the nuts on the breadboard terminal posts in place
- Wire nuts (x4) [optional] - for easily modifiable connections in the future
- Zip ties/Ty-wraps [optional]
- Wood glue [optional]
- Wood Filler/Putty [optional] - I splintered the plywood around the various holes and needed to patch the worst of these so I didn't hate myself every time I looked at the final product :-)
- Paint [optional] - I used untinted interior latex, but again, only because that's what I had and it was too cold to spray paint
- Breadboard Jumper Wires [optional] (Specifically these jumper wires) - supplementary to the project
- Drill (cordless and corded)
- Drill bits (3/8", 9/64", 1/8", 5/32", 2.5" hole saw) - probably others too
- Driver bits (flat head, Phillips head, and Hex head)
- Sand paper (100, 180, and 240 grits)
- Wood file and rasp
- Putty knife
- Spring clamps, C-clamps
- Pencil and marker
- Level, Measuring stick, Ruler, and/or measuring tape
- Screwdrivers (flat and Phillips heads)
- Compound Miter Saw
- Dremel rotary tool - sanding mostly
- Jig saw
- Paint Brush
- Utility knife
- Paper and transfer paper
- Painter's tape
- Diagonal cutters
Step 1: Breadboard Housing Construction
The basic requirements for the housing were that it contained the power supply unit, it had a forward tilt for the breadboard, and that it accommodated the pass through wiring of the breadboard terminals. As it turned out, the housing is 10 inches wide, 5 (front) to 7.25 (back) inches high, and 11.5 deep. I had leftover 1/2 inch plywood from a dining room chair pad/seat repair and a 1x1 wood post from a leftover sign post on hand, so that was my chosen media for the housing.
- [pencil, square, level/measuring stick] Measure and mark out the six sides of the housing on the plywood. Dimensions should be based on the size required to accommodate the PSU.
- Note: account for the width of the plywood and corner posts in the measurements and final size required.
- [level/measuring stick, jig saw] Recheck the measurements and cut out the sides with a jig saw (circular saw would probably provide straighter cuts than the jig saw, but even a hand saw should work).
- Note: a scrap backer board to prevent chipping when cutting is recommended for a nicer finished product.
- [wood file, rasp, sand paper] File and sand the newly cut pieces as necessary.
- Note: stack/clamp symmetrical sides when filing and sanding to eliminate variation in the two pieces from cutting.
- Each corner of the box has a 1x1 post for rigidity and to provide a fastening location for the plywood sides.
- [compound miter saw, square, pencil, clamps] Measure and cut the lengths needed for the corner supports.
- Note: the front posts should be cut at an angle equivalent to the lid or flat such that they are no taller than the front of the housing.
- [wood file, rasp, sand paper] File and sand the newly cut pieces as necessary.
- At this point all the wood pieces required should be cut out and sanded. It is advisable to measure and cut the openings required for the power supply unit on the back of the housing at this point and likewise with the hole in the lid to feed the wiring for the breadboard terminals. I did not do it this way so the rest is written as I did it, but I believe it would be easier prior to assembly when the wood is flat. This also allows the opportunity to use a scrap backer board to eliminate chipping when drilling/cutting the larger holes.
- [clamps] Align and secure a corner post to a side using the clamps. I recommend attaching the posts to the sides whose edge lines up directly with the post edge first. Pay close attention to which pieces need the 1/2 inch space from the side's edge in order to conceal the plywood end of the abutting side. For example, my housing front board is 10 inches long, but the back is only 9 inches in order to account for 1/2 inch for both of the sides.
- [drill, drill bits, clamps] Drill two pilot holes (of appropriate size for your selected fasteners) through the side and into the corner posts. Drill the tops of the holes again with a larger drill bit to create a recessed cavity in which to conceal the fastener head; alternatively, use a countersink bit if using basic wood screws.
- [wood glue] Optionally, unclamp the pieces just drilled and apply wood glue before re-clamping the pieces for a stronger joint.
- Note: I did not use wood glue and it seems very sturdy, so dealer's choice.
- [driver bits, fasteners, clamps] Attach the side piece to the corner post with your selected fasteners.
- Repeat the last three steps and assemble the four sides to the four corner posts, then move on to the bottom piece.
- Note: recessed fasteners are important on the bottom if you plan to employ round wood plugs as feet in the finished product because the plugs will need to match the size of the large hole, and have enough space to be hammered or tapped into place.
- [wood file, rasp, sand paper] This is a good point to file and sand to correct for any squareness issues caused by cutting or measuring errors, etc.
- [pencil, drill, drill bits, screwdriver] Measure, mark, and drill pilot holes for two small hinges for the lid on both the back piece of the housing and the end grain of the lid. Hinges can be tricky to get right, so take the time to make sure they are in line with each other and square. I used some small hinges I had from another display box I made years ago.
- I left an overhang on the lid for ease of opening and similarly I left an overhang on the bottom since without it, the lid seemed like it would look unbalanced. At this point I drilled and cut the hole in the lid for the wires coming off the back of the breadboard terminals to be fed through and attached to the PC PSU.
- [pencil, measuring stick, drill, drill bit, Dremel] Position and mark the location for the breadboard on the lid. Mark the cutout for the terminals in particular. Drill and cut out the hole for the wiring; enlarge and smooth the hole as needed/desired with a Dremel with a sanding or similar attachment.
- [pencil, drill, awl] Mark and drill four holes on the bread board that will be used to mount the board to the lid. I used the awl tool shown in the picture and tapped it with a hammer to mark the spots on the aluminum breadboard backing so a drill bit would grab easier. If you have an old screwdriver, that should work nearly as well, or just keep the drill bit from wandering across the metal.
- [transfer paper, awl, drill, drill bits] If you look back at the breadboard, it has multiple small screw heads on the back that keep it from sitting flush on the lid as is, so I marked those locations out on the lid and drilled recesses to accommodate the screw heads for a flush mounting of the breadboard. I ended up using a chemistry lab notebook from college that had transfer paper to the location of the screw heads. I then marked the locations in the wood through the paper using the same awl tool as before which made locating and starting drill holes in the right locations easy.
Step 2: Power Supply Cutouts
The pictures show the planned rough location of the power supply, the two holes that are needed (fan and power cord), the template that was created for marking the holes out, and the aftermath of the hole cutting. As previously mentioned, cutting the holes for the supply would likely be easier done before the wood for the housing is assembled. I didn't want to pull it all apart, so I pressed on and ended up chipping the wood between the two holes. It seemed bad enough to me that it might compromise the ability to securely fasten the supply in the housing, so I ended up patching the damage with wood filler.
- [pencil/marker, utility knife, measuring stick/ruler] Measure out the back of the power supply and transfer it to a paper template. I used the same lab notebook paper as before since it has a nice 1/4 inch grid.
- [pencil] Transfer the locations to the outside of the housing, by folding and taping the template and then tracing it.
- Note: account for the 1/2 inch width of the bottom board - don't start on the bottom edge of the housing.
- [drill, drill bits, rasp, file, sandpaper, Dremel, painter's tape] Cut out the holes for the fan and power cord.
- The fan hole was too big to take out in one chunk - you can see it's not exactly round if you look closely- but the biggest hole saw bit I had was 2.5 inches, so that's what I started with, then I used the Dremel, rasp, file, and sandpaper to enlarge the hole.
- The power cord hole was more manageable. I drilled two larger holes at either end of the marked area using a paddle or spade bit, then cut the wood between the two locations with various tools like the jig saw, Dremel, rasp, file, and sandpaper.
- [putty knife] At this point I used wood filler and a putty knife to fix the chipping I caused with the hole saw.
- [pencil, drill, drill bit, screwdriver] While the wood filler was drying, I added the bracket that acts as a multi-position lid prop. I manually positioned it, marked the location with a pencil, drilled a shallow pilot hole, and then attached it. The last picture shows the lid propped open at the lower position; a later picture shows it at a more elevated position.
- Note: it might be worthwhile to add a chain to keep the lid from flopping all the way over, but for now I didn't worry about it.
- Note: the bracket is later removed for painting.
Step 3: Finishing and Final Assembly
The housing is all done, but I thought a coat of paint would be good to make everything look uniformly colored and to hide my wood filler and other tool mark defects.
- [sandpaper] Go over the entire housing with sandpaper, starting with the coarsest and working to the finest. Wipe the box down to remove sanding debris/dust in preparation for painting. If using a damp cloth, let any moisture dry before painting.
- [interior latex paint, paint brush] Apply several coats of paint as necessary to all sides and the interior.
- [hammer/mallet] Add rounded wood plugs to the recessed fastener holes on the bottom of the housing. Use a piece of scrap wood between the hammer and plug or use a mallet to prevent marring.
- [interior latex paint, paint brush] Paint the bottom of the housing, including the rounded wood plugs.
- Remove excess paint from holes and recesses on the lid of the housing by quickly re-drilling the holes or swirling a screwdriver or similar tool in the holes.
- [utility knife, diagonal cutters] Cut four 8 inch pieces of wire and strip the ends. The wires will be used to attach the breadboard terminals to the correct PSU voltages. Optionally, color code the wire lengths to match the terminal posts or the PSU voltages.
- [wrench, super glue] For each of the four wires, wrap the end around a terminal post on the underside of the breadboard and tighten it down with the nut provided. Snug with a wrench and add a drop or two of super glue to lock the nut in place. Alternatively, if you have spare lock rings or lock nuts, those can be swapped out.
- [zip ties/ty wraps] Optionally, once all four terminals have one wire each attached, bundle the wires with small zip ties.
- [marker, tape] Optionally, mark and/or color code the wires and wire nuts to be used for connections.
- [screwdriver] Mount the breadboard to the housing lid using the four previously drilled mounting holes and the four sheet metal screws (or other chosen fastener), being certain to feed the wires for the terminals through the hole in the lid.
- If necessary, prepare the computer power supply to be used without it being connected to a 20 pin ATX motherboard connection. There are several places that cover doing this so I'm not going to duplicate it here. The one thing worth noting though is that this power supply is a Dell power supply which does not follow the standard ATX PSU pin out. Measure the outputs with a voltmeter or find the exact PSU model number if you are unsure. I wanted the four terminals to be ground, 3.3V, 5V, and 12V, respectively, so those are the items I located and connected.
- [zip ties/ty wraps] For this power supply, the 20 pin connector did not contain any 3.3V lines, so I used the 6 pin auxillary connector which had three 3.3V lines and 3 ground lines. I used a single 4 pin connector to pull 5V and 12V as well. I tied all three voltage grounds together with the GND terminal with the junction being made with a wire nut.
- Likewise the other terminals were connected using a wire nut junction in the off chance that I need to move those supply lines around in the future to support some other project. The wire nut junctions were secured with zip ties and the wire bundle in general was managed with zip ties.
- I selected to make the breadboard terminals (from left to right) black (GND), green (3.3V), yellow (5V), and red (12V).
- [Breadboard jumpers] Place breadboard jumper wires on the breadboard from the terminal to one of the provided voltage rails. Optionally, color code the jumpers to the terminals.
That really concludes the build. Hopefully this hasn't been too painful to follow, but I sort of expect this is an easy thing to look at and build without a lot of guidance. Someone else has probably already done this and done it better too. As a few final comments, I do have space in the housing to hold the power cable when it's disconnected, hold the breadboard jumpers (6 PVC tube segments stuck together), and also multiple electronics components (in a classy Altoids tin of course). There is enough space inside to store a fair number of things like a multimeter, tools, and/or components,
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Please be positive and constructive.