Okay, here’s the first part of the fixture — cut two of them, the top three holes are used to mount it to T-track (or adjust the spacing to match threaded holes/inserts)
The lower holes have a hex cap nut epoxied into the top, and 1/4"-20 threaded rod installed from the bottom — then cut a pair of boards w/ holes drilled in them which match the spacing of the two fixture boards, slide them onto the rods and use wing nuts to position them to match the board lengths.
There should also be 4 small pieces which have a vertical hole drilled through them, a pair of slots to hold a square nut, and holes drilled into either end which line up with the nuts — use plastic bolts to hold them in place on the threaded rod from one side, and adjust a bolt in the other to hold the boards vertically, with two offset by half the board thickness.
cncfingerjointbox_fixture_main.c2d (22.1 KB)