This unit can be made in an afternoon from stuff that you can find at any big-box home improvement store (I got everything from my local Home Depot) for less than 50$US. It can be much less if you work with what you already have, like I did. Note that the dimensions are easily modified from what I present- it is a very flexible and forgiving project. If you want to keep the costs to the absolute minimum, I would suggest that you stick to a board 4 feet wide by 3 feet high. That way you only need one sheet of white showerboard and a half-board of the plywood. Otherwise, the sky is the limit for materials! Note that the board shown here was 5 feet wide by 3 feet high, which gave me a nice big working space. Note also that I made it so you can use both sides. This makes is a nice room divider, too. If you were going to move it around a lot, I would add casters- it is pretty heavy when built.
Step 1: Planning and Materials.
Two 4 x 5 foot sheets of white tileboard
One 4 x 5 foot sheet of 5/8inch plywood (I used 3/5" MDF, because I had it around, but it is heavy!)
Four 8 foot long 2x4 inch studs (you will cut this into 4 6-foot lengths, two 2-foot lengths and (optionally) four 1-foot lengths cut at 45% angles)
Four 4.5 inch long, 3/8inch bolts (The length of the bolts will depend on what you use for the center of the boards.)
Four 3/8inch nuts (if you are careful in your measurements, you might be able to get away with acorn nuts, but getting that to work is tricky, even though it does look nice!)
Eight 3/8inch washers
Eight 1/4inch lag bolts (I actually used some little furniture assembly threaded inserts like this to make it easy to take apart, but I couldn't find them at Hope Depot, so you can use lag bolts instead.)
(optionally, 16 2.5inch drywall screws)
You will also need some basic hand tools:
A drill. Make sure that it is big enough to work with the large-sized bits that are used in the project. A good electric drill will probably work fine.
Drill bits: At minimum, you will need a 3/8 inch drill bit, 1 1/8 inch bit, and (depending on how you attach the feet) a 1/4 inch bit. You will also need a means to countersink the fasteners on the feet- I used a 1/2 inch spade bit, but you can use a Forstner bit or a countersink bit if you have one - I don't.
A pair of wrenches in the appropriate sizes. I used a ratchet set and an adjustable crescent wrench.
Measuring tools. At minimum, a measuring tape and a steel rule. A framing square or something similar in order to make sure that cuts are square.
Saw(s): I did all the cutting with a circular saw, using a crosscut blade for the 2x4s and a composite blade for the rest. If you are not cool (as I am not) an don't have a table saw, you can also use some straight steel angle-iron and clamps to provide a guide for your saw.
You will need a screwdriver to match any screws you choose to use. I needed a regular philips one for the drywall screws that I used.
A couple of clamps, preferably ones with soft non-marring jaws. I like the ratchet-action bar clamps from sears.
I also used a couple of sawhorses that I borrowed from a friend (hi, Pete!) in order to make it easier to do all the cuts. The MDF that I used as the center of the board made a dandy table before I cut it, too...
Step 2: Measure and Cut
Now cut each leg out with your saw. Note that I got all kinds of sawdust on my wife's car, so I probably should have taken it out of the garage first.
I corrected slight variations with my sander, so don't despair if they are not _exactly_ perfect.
After you have all the leg lengths, set them aside and measure and cut the two feet the same way, which are 2 feet long each. They do not need to be as exact as the legs, but you should probably be careful anyways.
At this point you can also cut out the optional foot supports if you want them- be careful and use the angle-cutting feature on your saw to accomplish this, and watch the cuts to make sure that they are in the correct direction. If you use four 8-foot 2x4s as I suggested, and you don't make any mistakes, you will have just enough for everything.
Now go ahead and mark the two pieces of showerboard and the middle piece of MDF/plywood/whatever to size. I found it easier to mark and cut the showerboard first and used the MDF as a "table" to support it. That showerboard is very floppy, and subject to creasing and damage if it folds over too much. I clamped it to the MDF, and used a length of angle-iron C-clamped down as a saw guide, and that both held the showerboard firmly and made for a very straight cut. If you don't have a table saw, this is a neat technique. If you are following my plans exactly, you should mark each of the main board parts at 4 feet high by 5 feet long. That long bit of angle-iron came in handy for marking the straight edges, too.
Once you have all three parts cut out, clamp them together carefully (I used the rubber-faced bar clamps to as not to mar the finish of the showerboard.) Now you can sand the edges so that they all meet cleanly along the sides. (That is the part that you see- feel free to sand the top and bottom, too, but I was being lazy.)
Step 3: Assemble the Legs
Once you have drilled out all the legs, go ahead and assemble them onto the board sandwich. Make use of the markings that you did during assembly to make sure that you have them all in the right places. If you are _really_ careful, this won't matter as much, but I have found that normal variation will creep into the construction, and you are better off keeping everything as it was initially assembled. You assemble them by bolting each of two legs on each side of the board with the 3/8in bolts. I added fender washers on both sides and lockwashers under the nuts to keep them from slipping off. I tightened then with a ratchet on the bolt head and a crescent wrench on the nut. It is easier to get started it you have a helper- I used my 11 year old...
Step 4: Assemble the Feet
Now square one of the feet up against the bottom of the legs as shown by the drawings. Use the marking you made to center the foot against the legs. Now you can trace along each of the legs to mark where they fall on the foot. Repeat this for each of the two feet. Now mark an "X" going from one corner of the markings to the other- this way you can easily find the center line of each foot. Mark this with a line across each box. (See the picture below to see how to do this- it is easier done than said.)
These lines serve as guidelines for the next steps. Mark a spot on each center line that is 1.5in in from each edge. If you are using threaded inserts like I am, you will need to drill a 1/4" hole at each marked point. If you are going to use a lag bolt instead, just drill the appropriate sized pilot hole. Be careful that it is the correct size- you do not want your wood to split.
Once you have drilled the four holes on your foot, match it up and clamp it to the legs using your marked lines, and then drill the matching holes in the legs using the holes in the feet as guides. Repeat this for the other foot. Now take one of the feet, and countersink the holes with a bit large enough to accommodate both bolt head and the ratchet driver you are going to use to drive it in. I avoided that particular problem by using bolts that have heads that use an Allen wrench. I used the a spade-bit drill of the appropriate size to drill the holes. Make sure that you drill it deep enough that the bolt heads are off the ground, but not so deep that you weaken the feet.
I redrilled out the holes in the legs about 1/2" with a 3/8" bit to allow the threaded insert to fit, which I then screwed in with a large Allen key. This is not necessary if you are using lag bolts.
Once all the drilling is complete on the legs and the feet, assemble the feet onto the legs and make sure that they fit well, and that the board stands up straight. You may need to take it apart and carefully trim/sand the legs if everything does not square up right. Once you are satisfied that everything is right, you are ready for the final finish and assembly.
Step 5: Finish and Final Assembly
I finished the legs and middle of the "sandwich" with black acrylic paint and several coats of spar urethane. I like that combination because it is very durable and leaves the grain of the wood visible in the black, which I think is cool. Your mileage will certainly vary- just remember that you are using it as a whiteboard, and that the marker "misses" will certainly hit the frame once in a while- the black hides that nicely.
I added a tray along the bottom of the board that I made out of parts left over from a disassembled aluminum screen door. My markers and eraser fit in there nicely. You can almost certainly do something similar, or even use some pine trim angle or something similar.
One thing that I did no do, but in retrospect wish that I did was to cut off the bolts holding the board on the legs and replacing the nuts with acorn bolts. My bolts stick out more than I would like them to, and they make the "back" side of the two-sided board not quite as nice as the front...
My whiteboard has been very stable and gets a lot of use in my lab/workshop. It is heavy enough to accommodate multiple excited hackers working on it at once. Since it easily disassembles, it is possible to move it if I have to. I hope that you have similar success and enjoyment from yours!~