Introduction: Geometric Planters
Sometimes an idea just comes together unexpectedly. In this case, I was looking to create a single box, not a system for creating these boxes, but found a way to make a whole series of boxes. Still, something that exists in theory or the perfect world of a 3D program doesn't always translate perfectly to reality, so it was extremely rewarding to see this work.
Be sure to check out the included video for the build process.
The primary tool in this process is a table saw. Most of the other tools could be substituted based on what you have, but I think the table saw combined with the sled we'll build is essential.
Other nice-to-have tools along the way:
Drill, brad nailer, scrollsaw, jigsaw or bandsaw for cutting the base shape, X-acto knife, sandpaper and finish.
~18" x 14" piece of plywood, a few other ply or hardwood scraps, glue, screws and whatever hardwood you wish to make the box from.
Step 1: The Concept
This system is based on hexagons, combining them along any of the edges. By using hexagons of the same size, it allows us to build all the walls by repeating the same 4 pieces.
Using this idea, we need to create a reliable way to cut 4 identical pieces again and again. I think the best option for this is a simple table saw sled, made from some scraps around the shop.
Step 2: Build the Sled
There are lots of i'bles and videos on building table saw sleds. You could make one that is fancier, or use another method for making sure it's accurate, I'm going to build just a basic sled.
The exact size of the sled doesn't matter, as long as it is wide enough to ride on the miter slots of your table saw and over ~12" deep. If you plan to make taller boxes, using wider boards, increase the size of your sled accordingly to accommodate those boards.
Cut the ply, make sure it is square on all sides. We'll be references the sides as part of making the sled accurate.
Cut runner stock that will slide in your miter slots. Make the height just shallow of the slot depth, then you'll be able to raise it with some card stock. Place the 2 runners on card stock so they sit just above the table, then using your table saw fence as a reference, set you plywood down on the runners using some fast curing glue. Leave the top there until the glue is secure or shoot a few brads into the runners to help secure their position.
Turn the sled over, countersink some screws to fully secure the runners into place. Test how well the base slides in the runners, and if it doesn't bind, wax the surface and work on the top.
Attach ~3" tall boards to the front and back of the sled, using 2-3 of them on each side. We'll be referencing the bottom edge, so make sure those boards are straight and secured well. (Also be careful if using brads or screws to NOT place any in the path of the blade.)
See the attached PDF for the printed guides. We need an angle of 11.2 on the sled. Cut this out from the paper and use it as a direct reference to draw that angle on the sled. Attach a straight board to this line. (NOTE: In the image, I created a 2-angle sled, the PDF shows one angle, which I found later works better.)
Attach another board on top of the angled board for extra rigidity of the sled and don't cut all the way through this board when you cut the sled in half.
Angle the saw blade to 28 degrees. There is an included angle in the PDF which you can cut out and use if you don't have an accurate angle finder. Cut only ~1/2 above the base of the sled.
The sled is now ready to use. In the PDF I include guides for cutting boards that are 3/8" or 1/2" wide. The height of your boards can be whatever you choose, but I do recommend you cut the angled channel into your boards first as a reference. Cut this at 20 degrees and as wide as the hexagon base you will use.
Step 3: Cutting Sequence
SAFETY NOTE: Brightly mark the area around the blade path, in several areas so you will never place a thumb or finger in harm's way. When cutting these small parts, it's important to keep them secure while keeping all your fingers. Definitely make and use a hold-down or toggle clamp.
The cutting sequence isn't that difficult, but it's also really easy to mess up. You'll be making cuts and flipping the board and if you accidentally flip the board without realizing it and keep going, all those new cuts will be wrong and you'll be confused and cussing during assembly.
For this reason, write some clear notes on the sled about which side should have the channel on it and so forth and just keep referencing your notes and the guide as you go.
Cut out the included full-size guides, depending on using a 3/8" or 1/2" board. Line these up exactly and mark the sled to know where to place your board during cutting operations.
Based on the guide, the 4 pieces are colored yellow (the largest and most common piece), cyan (the smallest and least common piece), and the magenta and blue pieces, which are mirrored, there will always be the same number of these pieces.
Yellow: Feed the board from right to left, cutting the first angle with the channel facing down and toward the base of the sled, flip the board so the channel is now up and toward the top. Line the board up according to the mark on the sled and make the cut.
Flip and repeat. This yellow piece results in an off-cut each time.
Cyan: Feed the board from right to left, starting with the channel facing up and toward the front of the sled. Flip the board, channel down toward the base for the 2nd cut.
Purple: Feed from left to right, channel facing up and toward the top. These cuts just go in sequence, no flipping of the board.
Blue: Feed from left to right, channel facing down, toward the base.
Note: It is possible to chain some of these cuts together to save a small amount of some offcuts, I found that it wasn't worth the effort of saving a few inches of the board at the risk of messing up the sequence. I recommend cutting all pieces of one color completely before moving to the next.
Step 4: Assembly and Glue Up
The hexagon size used for these examples is roughly 5" in diameter, but this will vary a bit based on how deep you cut your channel and how high up the board. This unfortunately just takes some trial and error to get right.
Cut out one or several hexagons and use these to draw the pattern you are creating. You can tape a few of your walls together to see how they look in relation to your drawing, but to really test it you'll need to cut out the pattern and test the fit.
Place the pieces together, a few at a time, tape the edges and this will help in dry fitting and later in glue-up. Work around the pattern shape to make sure everything fits correctly before adding glue.
I don't think there is any way to avoid glue squeeze out. Some of this you can clean up with a wet rag while you work through it, some you may need to chisel and sand away later.
If you plan to have live plants with soil and moisture, choose a very durable finish. I'm using artificial plants here and used Odie's Oil, which is an oil wax mixture that is somewhat water-resistant, but not sure it would be good for long term water exposure.
Reality notes: In my example, the 3-hexagon box has some small gaps, and the 6-hexagon box had a few more gaps. I applied a mixture of wood glue and sawdust to close that up, which later makes for more sanding and clean up, but it's one way to fix the small errors that are just a result of so many joints.
Step 5: Final Images
I may need to work on my arrangement skills, but still pretty happy with these planters. Good luck and please let me know if you give it a try.