Magnetic Checker Pieces

For this project, it requires:

1) .315″ × .125″ round neodymium magnets
2) 6″ × 10″ × .25″ Walnut (or wood of a given type)
3) 6″ × 10″ × .25″ Paduak (or wood of a given type that looks different to the first)
4) 1 hammer
5) scrap wood for driving in the magnets

Also I made this project using scrap wood I had around the shop. I had a bunch of a narrow 1.63″ × 24″ × .25″ (on average) boards. The project is set up for that. However, I will add a second cutting reference file for doing them all at once.

Step One:
Mount your piece of wood squarely in place with the clamps.

On my machine I did this by screwing in a piece of wood for an absolute zero registration with a 1/8th inch bit. All my cuts will follow along the same y axis zero and will be referenced to it. I will post another file for that to ensure a perfect square to your machine.

Step Two:
Allow the CNC machine to run through the file. I always allow the machine to mill slightly deeper than what is needed to account of rises or offsets on the wood.
Please just reset the overall cut versus the depth on the center holes for the magnets. They are suppose do to be a pressure fit.

Step Three:
Once the cut is complete, chip out the wood pieces. If your chisel cannot fit inside the piece, turn the wood over and align it on the tab. One quick hit should cut through the tab without chipping out the top of the pieces. This design does account for 3 additional pieces if mistakes happen.

Step One:
Take your stack of magnets and attempt a pressure fit. If the magnet should resist being pushed into the wood. It should require laying a piece of flat scrap wood, and rock the magnet into its required slot.
Go for a shallow fit on it for now.

Step Two:
Repeat the process for all 24 pieces. You should have 12 of both color. Check the alignment of the magnets as you go. This can be done by putting the shallow fit pieces in a stack. The magnets should pull them together.

Step Three:
Hammering the magnets into place. Lay the piece of scrap wood on top of the magnet then using the hammer drive it down into the piece. There should be a small snap as the magnet is driven home.

Step Four:
Recheck the alignment of the pieces by placing them into stacks. The pieces should all stack up evenly.

Special Notes:
If you want to be fancy, you can drive in the magnets for one type of wood in the reverse magnetic pull. That way the pieces only work with the matching color.

You do have spare pieces of you happen to drive in the magnets backwards. You can also drill a hole along the side of the magnet then take a screwdriver and pull the magnet back out. It does sacrifice the piece, but it preserves the magnet.

Step One:
Sand down the edges and tab marks on the wood. I recommend proceeding immediately to 220 grit sand paper and work slow. Being aggressive with the sanding will result in the pieces looking lopsided or just otherwise off. The human eye is pretty good at knowing when a circle isnt quite perfect, so just work slow.
I also recommend laying out the sheet of sandpaper on a level surface and moving the piece across it. After the sides are done, sand down the top of the piece by doing gentle circles on the paper. If you want to give a slightly more gentle profile on the pieces, lightly sand over the edge with the sandpaper.
Do not sand the bases unless you haven’t slotted the magnets. Sanding the bases will remove the protective coating from the magnets and could cause trouble down the road.

Step Two:
Apply your ideal finish to the wood gently. I personally used Boiled Linseed oil. It is my go to finish for all the wood I work with. To make the pieces a little shinier, feel free to try to use a finishing wax. Just keep in mind, holding the pieces steady during the polishing process can be tough and result in pieces launched across the room or well polished fingers.