The idea here is one of those projects that sounds simple until you think it through: machining working LEGO bricks out of wood on a CNC router. This was the maker's second run at double-sided milling, and the finished pieces came out well enough that the maker is pleased with how they turned out.
The workflow started with 3D models of the bricks in Fusion 360, then toolpaths were simulated for the underside cavities and the top studs. The hollow tubes under each brick were milled first, and after that the stock was flipped to cut the studs and the perimeters. For the flip, an MDF alignment fixture with registration pins held everything in place. The material is planed hardwood flooring stock, cut with a 1/16th inch bit to allow more stock removal, all on a CNC Router Parts machine. Twenty-four bricks came out of the run.
A couple of details stand out. The clutch power was tested against standard black plastic bricks, and the wooden versions actually fit into a model. The maker also stacked the finished bricks into a tiered rectangular structure, which is a nice way to show off a batch. The settings posted include H4 for tool length compensation and 0.6 for the rapid Z movement.
It is not flawless. A G-code glitch made the Z-axis jump and snapped some bits, which had to be removed by hand, and small offsets showed up around the registration pins during the flip. The maker is asking for feedback on the location pin setup, and plans to switch from 3D adaptive toolpaths to 2D clearing on future runs to tighten up the passes.
Project by I Do Things. Watch it on their YouTube channel: