I recently became proficient in metalworking and decided I wanted to practice my skills. One of my other recent interests has been plants, so I decided to make a bare metal frame planter. Air plants don't really need soil, so they are perfect for such a sculpture.
This instructable assumes you already have some basic welding skills. If you don't, get some extra material and practice sticking some of the same rod stock together.
The steps in this instructable are mostly about framing. The mechanical steps necessary to frame something with a high level of accuracy actually takes a bit of experimentation. This shows a lot of little tricks that may help in getting there.
Step 1: Planning / Materials
I started out by mocking up the model using 3D sketches and pipes in Fusion 360.
One thing I didn't like about this process is the connections between the pipes were all converted into mitres. This isn't actually how I wanted to build it for various reasons, so I set about finding an alternative way to build certain parts of the model, so I could get more precise measurements of the required materials.
After measuring the model I figured out I needed a 20' piece of 3/16" round stock to build this pyramid cube. I had to get 6' sections to bring it back in the truck. Keep in mind these sorts of constraints. Logistics can be a killer for getting materials
Step 2: Tools
Here's the tools I suggest getting:
Welding magnets (I used 2)
24" bolt cutters
Other welding tools:
Step 3: Cut Material
Use the C-Clamp to clamp the material to the table. Measure and mark where the material should be cut using the pen. Use 24" bolt cutters to cut to correct lengths.
Keep in mind though, the bolt cutters leave bite marks that you'll have to grind down. So you probably don't want to cut exactly on the line, but slightly over.
Four 1' pieces.
Eight 11.813" pieces.
Four pieces approximately 20.78".
Wait to cut the last four pieces until you build a cube. That's because the tolerances of the center parts are not precise not all the pieces can pass exactly through the center, so some experimentation is necessary.
Step 4: Sand Down Imprecise Cuts
It's important that the cuts be as precise as possible for the cube to look right. The strategy that seems to work well is cutting the rod as close as possible, but slightly longer, and then grind it down on the disc sander. This often means grinding a bit, measuring against a tape measure or an existing rod that is exact, then going back and grinding again if it's still not right.
Step 5: Align, Clamp, Magnet
Place two rods inside the carpenter square. One should be the full 1 foot long rod, and the other should be the slightly shorter rod, butting up against the longer rod.
Clamp the longer to the table. Use a magnet to hold the other rod against the carpenter square.
Step 6: Move Carpenter Square
At the point the longer rod is essentially locked in place, but the shorter one is more movable.
Before welding the joint, move the carpenter square so it doesn't get accidentally welded to the joint. To do this, hold the rod down with one hand, while sliding the square back with the other.
Step 7: Tack Corner
Once the carpenter square is moved, tack the corner with the welder.
The welder settings I used were 166 speed and 18 power, but your settings may vary. There's usually a chart inside the welder.
Repeat the process from step 5 with two other rods, making sure to keep the small rod butting up against the longer rod the same as before.
Step 8: Weld Square
Once there are two corners, clamp one corner to the table and then place the other up against the first.
Checking for squareness with the carpenter square, lock it in place with the magnet. I hold down the rod and tack the corner opposite the carpenter square. While hold the mutable rod down, moved the carpenter square carefully and tack the other corner.
Step 9: Make Another Square
Here's an artistic rendering of what is done so far and what is coming up next.
Make another square using the same process starting from step 5.
Step 10: Add Verticals
Next add the vertical parts to one square.
Put the square on the welding table and put two magnets at one of the corners butting up against each other on the outside. Use the magnets to hold the vertical in the correct spot. Tack the vertical. Remove magnets. Check for square. Fill in weld.
Repeat this process for all four corners.
Step 11: Weld Top Square
Flip the whole sculpture over and place it on top of the other square. Use two magnets to keep the corner relatively square, similar to how you did on the first side.
One thing to watch out for is whether the sculpture sits flat. This is where all your checking for squareness will pay off! The more precise you are in your cuts and your checks for square, the more likely you will have a flat side.
Once the cube is complete, I check all the sides and select the one that was the most flat as the bottom.
Step 12: Cut Diagonals
This is where things tend to get a bit fidgety. Lay a rod across the diagonal. Mark the place that you think will let it fit best. Getting the rod to fit between the two opposite corners of the sculpture is tricky. Sometimes the whole structure flexes. You want to be careful to not distort it too much. Every time the rod is stuck between the corners, wobble the cube and make sure that it still sits flat. If it's flexing too much, it's probably creating too much tension and needs to be shorter. Just don't make it too short.
As before, cut fairly close to the right place with the bolt cutters, then knock it down a bit at a time with the disc sander. But don't spend too much time knocking it down continuously. If you use the disc grinder too much, the metal may heat up and distort.
Step 13: Weld Diagonals
This is pretty self explanatory and the only real advice I can give is that it will probably not be a perfect triangle. There will be some amount of imprecision in the center, but you'll have beautiful plants there to cover this imprecision! If you lay the rods in the same way as this picture it's likely they'll all fit. Make sure to keep checking whether the sculpture sits flat by wobbling it as you weld each corner. I like to tack one rod at a time, then once they're all there fill in the welds.
After all the welding is done you may want to grind off some parts. Just be careful that the cube still sits flat on the bottom.
Step 14: Adding Plants
I specifically chose Tillandsias, also called air plants, as they don't actually require soil.
Instead I wrapped them in some Reindeer moss and some fabric.
The arrangement of the plants is up to you and what you can find locally!
If you don't have any florists that have air plants you might be able to order some from the internet.
I tied parts of the fabric to the sculpture and tied other parts of it to itself.
There are proper instructions for care on the internet. This instructable is mainly about welding the structure, so I'll leave that research up to you.