Total wood use , excluding prototyping, was 14 eight-foot (3x1 nominal, I think) furring strips and about 50" of 2x4 - about 25$.
I also used about about 250 1.25" staples and maybe 6-8 oz of wood glue, though you could get away with somewhat less of both.
As far as tools go, you'll need a radial arm saw (or suitable substitute), some way to rip a few furring strips in half (a table saw or band saw with a fence would be ideal), and a brad or staple gun.
Total build time, excluding design, prototyping, and rework, was about 5 hours - about two hours of cutting and three hours of assembly.
I'm providing a [pro/ENGINEER 5] parametric sketch so that you can modify the design to make it in different sizes, or for slightly different uses, like lightweight tables. (at this time, I can't figure out how to attach files, so I'm hosting it here.)
Step 1: Cut Wood
For the frames:
- 6*4 = 24 pieces of furring strip, length 17.25"
- 6*4 = 24 pieces of 2x4 cut into 90º-45º-45º triangles - the small way, where the legs of the 90º angle are 3.5" long
For the bases:
- 2*4 = 8 pieces of furring strip, length 37.75" (legs)
- 2*2 = 4 pieces of furring strip, length 51.5" (long horizontal member)
- 2*2 = 4 pieces of furring strip, length 18.25" (short horizontal member)
- 2*4 = 8 pieces of half-furring strip, length 3.37" (short sections of frame-shelf inside corner bracing)
- 2*4 = 8 pieces of half-furring strip, length 4.1" (longer sections of frame-shelf inside corner bracing)
- 2*2 = 4 pieces of half-furring strip, length about 35" (long sections of frame-shelf along inside of long horizontal member)
- 2*2*4 = 16 pieces of half-furring strip, length 12.9" (diagonal corner-braces)
- 2*2 = 4 pieces of half-furring strip, length 18.25" (the leg-stays)
- 2*4 = 8 pieces of 2x4 cut into 90º-45º-45º triangles - the big way, where the legs of the 90º angle are 5" long
- The diagonal corner-braces and sections of frame-shelf have their ends cut at 45º angles. The length is the total overall length.
- Regarding the little sections of frame-shelf: the shape is chiral, and you actually need 4 of each handedness in each size. That is, you need 4 left-handed 3.4" chunks, 4 right-handed 3.4" chunks, 4 left-handed 4.1" chunks, and 4 right-handed 4.1" chunks. I've included a picture demonstrating an easy way to produce these pieces.
- The above dimensions embody four refinements from the base I actually built:
- Two lengths of short-frame-shelf, rather than one. (Woops.)
- Length of leg-stays as 18.25" rather than 18.5". (forgot a factor in the tolerance stack-up)
- Long length of the frame-shelf cut with 45º angles on each end, instead of being lazy like I was.
- Trust my initial calculations, not the work-site recalcs, and make the long horizontal member 51.5", not 50".
Step 2: Modify Wood for Frames
Once that's done, clamp the strips of wood in a vice - I did this in 4-piece batches - and chamfer the top and bottom corners.
Step 3: Glue Up the Frames
Honest, set up the jig. It's worth it.
Once you've done that, you can assemble a frame as follows:
- Apply glue to a set (4) of 2x4 blocks. Remember that the rough, end-grain cut will need a fair amount of glue, so be sure to use enough.
- Hold everything snug against the little block of wood at the corner of the jig and firmly against the table.
- Staple the first frame member to the 2x4 block.
- Make sure everything is snug again.
- Staple the second frame member to the 2x4 block.
- Repeat 2-through-5 to staple the other three corners. (I rotated the workpiece counter-clockwise as I added new boards on the left-hand side.)
Step 4: Glue Up the Bases
- Using a block of furring strip (or section of whatever you are using for legs, I guess) to space the boards in the right place, glue & staple the frame as shown in the first picture.
- Gently flip the frame over, then attach the little chiral bits. Conveniently, 2.25"-0.75" = 1.5" == the width of a 2x4, no we can just use a bit of furring strip to align the chiral bits in their correct locations. A bit of glue and a single staple should do it.
- Using the partially completed frame as a jig component, assemble the pairs of legs together with the leg stays. (definitely see picture 3)
- Apply some glue, turn the legs up, make sure everything is square, and add some staples to make them stay put (see picture 4)
- Apply glue to the relevant surfaces of the diagonal corner braces and then, supporting the corner braces the right distance from the floor on bits of furring strip, add staples in the order indicated in picture 5.
- Finish by measuring for and then adding the long section of frame shelf. (I recommend measuring for it, rather than just cutting it to length from the plan, because there's a lot of tolerance stack-up feeding into its length)
Step 5: Use
Place frames on bases.
Get another person and have them help you lift one base onto the other
Fill with stuff
Retrieve that person again and have them help you take the top base down
Take frames off bases and bags off frames.