It’s puzzling
Once the word got around that I was willing to work on projects for teachers, I started to get a lot of requests. I had to turn down most of them for lack of time, but occasionally I would get one that seemed interesting. A request for a fun way to help kids learn their letters and how to spell was one of the ones that I took on.
I’ve always been interested in puzzles, so figured that a set of plywood cutouts that interlocked like puzzle pieces, with letters and numbers engraved into them, might be a good option. 1/2" Baltic Birch plywood was the material I chose, cut into 20" x 30" blanks to efficiently use the 60"x60" sheets it comes in. And I learned pretty quickly that I had to add a little bit of “slop” into the fit, so that kids could easily stick them together and take them apart without needing a hammer!
Rather that having to paint each letter after it was v-carved, a fussy job for sure, it was much easier to paint the blanks in bright primary colors before cutting and leave the cutout letters unpainted.
Having all my blanks the same size let me save a bunch of bit changes by doing all the v-carving in the whole stack of blanks, and then changing to an end mill to cut out the pieces. The number of pieces in each set was determined by the frequency of letters in a Scrabble game, plus a handful of numbers and punctuation characters.
These letters turned out to be really popular and I ended up making a set of each pre-K, kindergarten, and 1st grade class at the school. The last I heard they are still being used, though imagine they are getting pretty ratty looking by now!
Besides their use as a learning toy, I’ve used this same sort of puzzle connection for all kinds of things over the years. Everything from signs to a floor for a friend. Even modified these “Letter Linkers” to have connections on all edges to make them more Scrabble-like