After finishing building the desk for my new study, I had a large chunk of OSB board left over. I thought I’d design some overly ornate shelves that I could make on the shop bot at FabLab. Since I was using a CNC router I decided to use straight lines when absolutely necessary. I’ve always thought cutting square’s out with a CNC machine was a waste of potential!
I ended up with a design for some shelves that are loosely inspired by the Pleurotus ostreatus mushroom that grows out of tree trunks.
The main challenge to make these shelves was to cleanly cut the OSB without it splintering. Because the wood chips in this board are so large, they can very easily tear out and look horrible. To avoid the splintering I first cut halfway through the board with a down cutter. The downward spiral on these cutters pushes the chips into the board as it cuts so the top edge doesn’t fray.
After I’d cut the pockets and half cut the edges with the down cutter I switched to an up cutter. This cut through the final thickness of the board and meant the bottom edges didn’t splinter either. The close-up below shows the edge quality straight off the machine.
Although the cuts came out perfectly for these shelves I made a few mistakes with the design. The diagonal supports don’t lie flush against the back board, and I found cutting OSB to a point is not a good idea. With this in mind I’ve updated my design so the parts fit together more snugly and don’t taper into ragged points!
You can download my design in either Autocad DXF or PDF format. I used 18mm thick OSB to make these shelves, although you can make them out of any board which is 18mm thick if you want. On the drawings the yellow parts need to be cut as 11mm deep pockets, and the green lines are the outlines that must be cut all the way through the board. I recommend using the DXF file if possible since it preserves the curves more accurately than the PDF file does.