Quick and Easy Project Case

About: I have always loved the interface between the machine-like aspect of living things, and an increasing tendency for machines to act in a life-like way. As a result, I have been involved in computational biol...

This project shows how to build a simple project case out of hardware store materials in about an afternoon. It is particularly suitable for projects that need user controls or displays. For this example, I built a case for the amazing "Wacky sound generator" from www.musicfromouterspace.com.

Step 1: Sketch the Project Layout, Sketch the Console Layout, Taking Into Account the Size of Any Controls Needed, Any Plugs or Ports, Batteries, Etc.

By looking at the number and type of controls you have planned for the project, make a rough sketch. You can make it pretty rough- I have included mine as an example. Note that you want to design it "flattened out" and plan to leave space for bottom attachment of the circuit board as well as a place to attach the bottom plate. Take note of the "tabs" going down the sides of the main box- they are how the final metal portion of the case will attach to the wooden sides, and they must be far enough apart not to interfere with one another when the case is bent.

Step 2: Turn the Layout Into a Prototype Design.

Once you are satisfied with the basic layout, create a measured version to use as a component and console layout. You can use the examples I provided as a template for your own designs. I used the open source program "Inkscape" to produce my template- it is a nicely featured peice of software, using SVG as its file format. (see http://www.inkscape.org/) Pretty much anything that has measuring tools can be used to create the layout, or you can use regular drafting tools on paper, although it is a lot easier if you can make copies as you go.

The point to to make an "open bottom" box, which is folded from sheet metal on all four sides, but that stiill has an opening on the bottom for acces to the PC board and components (including a battery, if desired) inside. The 4-sided box is then secured to the wooden sides with screws via a series of small tabs down the vertical sides.

A couple of useful tips- first, create the component layout in one layer, and place the console markings and layout in another layer. This makes it easier to make all the needed templates later in the process. The second tip is to use your component layout to make sure that the hidden portions of the console components do not interfere with one another. I measured the size of the petentiometers, for example, and then I made a measured circle to represent them in the layout, so that I knew how far they would extend and I could see how they were going to fit, and make and required changes.

Also, make sure that the drill holes are marked, and that they are the correct size. Clearly mark the centers of each, to simplify punching/drilling later. Also, another layer with text indicating the drill size to use is a nice feature- you can enable that layer when you print the component template.

Once you have made the template, print it or make a copy, and cut it out. By folding the paper into the rough shape you want, you can ensue that the layout is correct, and that the tabs do not interfere with one another when the box is assebled.

Step 3: Measure and Cut the Required Endpieces.

When you are satisfied with the template, you can use it to generate the measurement for a pair of wooden sides. Measure the meight from top to bottom of the case, leaving some clearance on the bottom of the case. I left about 5mm or so, but more is okay too. I left almost no clearance at the top, with the wooden sides ending at the peaked top of the case. With the measurements in hand, you can either create a template to cut the sides from, or you can directly cut the sides from whatever you are using for the sides. I used 3/4" plywood for my sides, simply because I had a lot of it around as scrap. It is overkill, and I would suggest 1/4" as a good size, and easier to work with, at least for small projects. Use your judgement.

From the template you create, or directly, cut out the wooden endpieces, verifying that they are a matched pair when you are done. I used a miter box to cut mine, but a table saw probably would have been better. A perfect fit is not required, but, of course, the final appearance depends on getting clean aand even cuts. I clamped my endpieces together and sanded the edges with a sandpaper block to make sure that everything came out evenly. The sides of mine were already painted white when I cut them, so I left it as is.

Step 4: Create the Component Template.

Once you have cut the endpeices, and you are satisfied with the template, you can prepare the template. You will need something to use as the body of the box. I use thin stainless steel from the "furnace duct" section of the hardware store. it is cheap and easy to work.

You need to glue the paper pattern to the sheet metal using a removable adhesive. I like 3M Post-it glue stick, which sticks pretty well and is easy to remove. Spread the adhesive all over the back of the template, and then press it glue side down on your sheet metal. You can use a roller or the palm of your hands to make sure that it is attached securely. If some comes up. just add a little more glue and push it back down again.

Once you have attached it firmly, you are ready to cut out the template. Note on my example, I did not put the tabs in explicitly, but rather left space along the edges to cut them out as needed. it is probably better to put them in by design, but I did not do it this time...

Step 5: Use the Template As a Pattern to Cut Out the Sheet Metal.

Now cut out the template according to the plan. I used standard straight aircraft shears to cut out the straight cuts, and I used a "nibbler" to cut out the tabs. In retrospect, I should have nibbled more off than I did, but the box still came out okay.

Step 6: Drill the Component Holes, Based on the Template.

Once the basic form has been cut out, use a punch to mark the center of each circle to be drilled out. This is where marking the center of your drill spots with crosshairs really pays off. It makes it a lot easier to get the exact center of each hole. note that I have also punched some marks by eye on the tabs to make places for securing the edges of the case.

I drilled the holes with a little drill press (dremmel tool in their drill press stand) starting with a very small bit and working stepwise to larger bits. I should have used a "step bit" as the larger holes still came out ragged, and needed to be cleaned up later in the process. Since the holes are meant to be locations for potentiometers, there is no harm done, but for higher precision applications, more care and better tooling are necessary.

Step 7: Bend the Box, Starting From the Outside In.

In order to make the bends in your box, start with the outermost bends, and align the bend line with the edge of your workbench. Clamp a straight-edged piece of wood over the top, again aligning to the bend line. Now use another straight peice of wood as a lever to make a neat sharp bend of the appropriate angle in the metal. For subsequent bends, repeat the same technique. As the box starts to close, or for harder to reach bends, you can substitute narrower peices of wood, angle iron, or even the narrow edge of a taller piece in order to get enough room to move.

At this point, you should also bend the tabs inward, perhaps with the help of a couple pair of pliers. Be careful here, as the edges are sharp and you can cut yourself.

This is another step where having the right tool (a sheet metal brake in this case) would be really helpful, but for something of this precicion, it is really not necessary.

Step 8: Match the Profile on the Endpieces to the Bent Box.

Now is the time to check your design to ensure that the box is correctly and symetrically bent. If I was not so lazy, I could have made the endpices more attractive than mere squares, by cutting them off to more closely follow the contour of the metal box. Alas. I did not. Adjust the bends by hand on your box of neccesary.

Step 9: Mark and Drill the Attachment Points, Sheet Metal to Ends.

Align the endpieces one at a time, and mark the screw-holes with a pen or pencil. I used a nailset to pinch at these marks, and then I drilled them a little way into the wood endpieces on my drill press. You can then attach the ends, working with a stuby screwdriver (or right hand driver, if you have one) through the hole in the box bottom to screw the metal to the wood with short self-taping woodscrews.

At this point, I also cleaned up the holes with a deburring tool. If I had used a step-dril or something similar, this step would have not been necesary, but it worked out just fine for this project.

Step 10: Make the Console Label, Based on the Final Component Layout.

Now, work with your console layout file to generate a matching console label. This is the place to put the indexing marks for the potentiometers, label the lights, and add all the cool decoration for your case. If you have a suitable printer, you can even doo neat designs in color. If your printer ink is not waterproof, though, be sure and coat it with the appropriate sealer. Krylon makes a nuber of good products- find one that works with your printer inks an use it.

I chose to use my laserprinter, and I printed onto Avery 8.5x11 labels, which worked out just fine. Once you are happy with the layout, print onto the label paper, and then cut the labels out.

Step 11: Attach the Console Label to the Panel.

Carefully align the label on your case, and seal the label down. I used light marks where the drilled centers were to go to help me align the label before I sealed it to the case.

Step 12: Insert the Contol Components.

Now is the time to insert the control components into their respective holes. Most potentiometers and switches are secured by a coaxial nut and washer that must be removed before the shaft is inserted into the corresponding hole on the board. I made my leads extra long to allow the board to be handled while the controls are inserted to ease servicing and adjustment. I does make it a little crowded in the box, though. Once each component is secured, tighten the nut and washer with a wrench of the appropriate size

Step 13: Put the PCB in and Secure It With Standoffs.

I made standoffs out of nylon tubing and nuts/bols of the correct size. Make sure and give you board ample room above and below the components for clearance. I mounted my circuit board on the botom plate for the box, so that it can then be screwed into the bottom of the box once the board is secure. I had to be careful to make sure that there was enough room for the board to mate to the bottom of the case with enough clearance to allow the board to pass through the hole. I had to do a little adjusting after all, to make sure that it fit correctly.

Step 14: Secure the Bottom Plate.

Once the circuit board is attached to the bottom plate, and the connecting wires safely inside the box, attach the bottom plate onto the bottom of the case with self-taping sheet metal screws.

Step 15: Put on the Knobs and Finish Up.

Attach the knobs and admire your creation!



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    13 Discussions


    7 years ago on Step 9

    nice!! please tell me the name of the red tool in thsi picture andits use this is the stuby screwdriver? i wil be great if you share the electronic diagram of this too!!

    1 reply

    Reply 7 years ago on Step 9

    Thanks for the compliment! The red device is called a deburring tool, and is used to clean up holes after you drill them. It works great for both metal and plastic. The one in the picture came from my local hardware store, and only cost about US$2 or so. It has extra bits in the handle, which is both cool and handy! You use it by putting the tip into the freshly-drilled hole, and then dragging the tool around the inside of the hole - the bit has a sharp inside edge that cuts off the jaggeddy left-over metal/plastic. This tool allows the bit to swivel as you turn it, which is nice. If you wanted to order one very much like it, try: http://bit.ly/dHOQPo Good luck!


    Reply 9 years ago on Introduction

    Thanks for the comment!  I have built another one, using similar principles that fits a 19-inch rack-mount synth case.  pretty cool, easy and fun!


    10 years ago on Step 15

    Very nice instructable. I have finally amassed all the components I need to make my 1st WSG, and just last week broke down n bought the PCB from Ray Wilson. I had planned on using a generic board 1st, but changed my mind as it is my 1st "real" synth from scratch build and I was apprehensive. Did u etch your own? it looks different than mine. I like the addition of the volume knob, too.One question, please. Is the sheet metal u used sturdy enough? I thought duct work is pretty soft, and I was thinking of aluminum. Also, any tips for a 1st time WSGer??

    1 reply

    Reply 10 years ago on Introduction

    The ductwork material is pretty soft, and is certainly not ideal for project cases, but by strengthening the structure by bending the ends over and securing to the wood blocks on either side, it is stiff enough to function. The reason I chose the material is that it is easy to work, readily available in every hardware store in the world, and found in copious amounts as scrap at many construction sites. By all means use stiffer aluminum if you have it or eve steel if you have a real brake- the results will certainly be better. As for suggestions for making your first synth- mainly take your time. I can't tell you how many times I had to go back and resolder a cold joint, reverse a component, etc. The nice thing is that the WSG is pretty forgiving, so you at least get a chance to fix things...


    11 years ago on Introduction

    hey very nice one. But what if you had to insert linear "slider" pots? How could you cut straight holes? what tool would you reccomend to do a neat job? Thanks!

    1 reply

    Reply 10 years ago on Introduction

    One way to cut slots is to drill holes at each end of the slot, and then use the "nibbler" tool (Illustrated in Step 5) to cut the line between the two drilled holes, and to square the ends. I have cut slots for linear pots that way in the past and it works pretty well. You can buy a nibbler at the local hardware store, and I have even seen them at Radio Shack in the past.

    The synth plans that I used are freely avaioable from the excellent "music from outer space" <a rel="nofollow" href="http://www.musicfromouterspace.com/analogsynth/YOUR_FIRST_SYNTH/YOUR_FIRST_SYNTH.html">website</a>. They are easy to use and fun to play with!<br/>


    12 years ago

    Fantastic suggestion, ehmbee! It would certainly look cooler with the ends recessed, or at least finished. I had wanted to use some 1/8" pine scraps that I had, but they were not quite big enough. I figured if they were sanded and stained, it would look more like a classic synth case. Next one I make, I will try your suggestions, and perhaps prime and paint the case black. The only question then is how to have the labels stand out. Maybe silkscreen them?


    12 years ago

    Nice way to make fast and light work of a project box! you could probably also bend your metal the way you wanted, then measure and cut your wood ends to fit-screw it all down with your ends recessed behind the metal, and flush, and it would look almost store bought....either way gets it done, I guess I'm just picky that way, I got too many people laughing at MY mad scientist projects as it is....for a really finished look, I'd try to cement some scrap countertop laminate on your wood ends!!! I'm sure that stuff is free for the asking in small, broken pieces at home centers or from kitchen contractors. If you can keep your project's ends under about 2"x3" (a big IF), Formica samples are are just that size, and available free on their website. They also have metal ones too, for their metal countertops and cabinet door coverings. These also make great backing panels for switches and that kind of thing.