I've been wanting to make some building blocks for my kids, and this weekend I got a few moments to make it happen. I ended up with 27, 3 x 1.5 inch, and 46, 1.5 x 1.5 inch blocks. They fit nicely in a plywood box made from birch plywood.
Before getting into the build, there isn't really any reason to make blocks except to make the blocks. Although cheaper, they're not really any nicer than what I could buy, I didn't pick up any new skills, and the fact that sanding was ~90% of the effort doesn't make it look like it was worth it. But- I think I ended up with a decent number of nicer blocks that will stick around for a while.
To start, I cut a 2x4 in half using my hand saw. I ripped one edge off each half (to remove the round over), and then ripped the boards into strips 1.5" wide on the table saw.
I set a stop on my table saw sled to cut the strips into the blocks. I cut two of the strips into lengths of 3" long, and the other 2 into lengths of 1.5". This gave me rectangles and squares for the set.
As I noted before, from the one 2x4, I was able to cut 27, 3 x 1.5 inch and 46, 1.5 x 1.5 inch blocks. There were several pieces that weren't usable because they landed bad on a knot, or the edge of the board was chewed up.
With the blocks stacked, I measured around them for the box. The stack stood about 6" high with a 7.5 x 7.5 inch foot print. I made the inside of the box a 1/4" larger in all 4 directions to give room for the blocks to slide in and out.
The box is simple constructions, with the 3/4" plywood sides joined together with pocket screws and glue. The bottom was made from a piece of 1/4" plywood glued into a groove cut 1/4" from the bottom. I used iron-on edge banding to cover the edges along the sides of the box, and hide where the groove cut through the end.
After the box was built, I cut some short lengths of poplar to serve as handles. The handles are 6" long, ~1" wide, and 1/2" high). The handles are just glued to the side of the box; no nails or screws needed.
I sanded the blocks with 80-grit paper using my random orbit sander. A belt sander would have worked better, but this worked OK for removing the mill marks. The random orbit sander doesn't have a uniform a pattern, and each block had to be moved around on the pad a lot.
Each block was then sanded with 120-grit paper to finish smooth the sides and ease all the edges and corners. For this, I just taped a piece of sand paper to my work bench, and moved each block across the paper. My son came out for this part, and hit all the blocks with 150-grit paper.
I finished the blocks by wiping on 2 coats of shellac, and I gave the box 3 coats. Although you don't have to do anything to the blocks, the shellac should make the blocks easier to clean and protect them from slobber. Also, even though it is just a 2x4, some of the blocks have a pretty grain, and the shellac really highlights it.