This was my first attempt at making steel furniture (and now instructables!) I wanted to work with complex angles to make a table base that was strong and intriguing. The legs are to be used in an Architecture shop, so I wanted the design to inspire, while being structurally sound (Shops are not the kindest place to tables)
The final design, while visually complex, actually comprised of simple 45 degree angles. This made the cuts incredibly easy, as they were many 45 degree and 30 degree cuts.
Step 1: Final Design
Unfortunately, I lost many of the process pictures along with my phone. But have included the 3D model file for those who would like to follow along! The cuts are marked on each side with a roofing triangle and chalk pencil, these are then cut with a simple angle grinder. These cuts are hard to get pretty. Luckily, metal is forgiving! any gaps encountered when finishing the layout can be fixed with weld.
Step 2: Weld Each Leg Separately
After the cuts (angles can be derived from the 3D model) align the cuts so the 2 flat 90 degree angles join together. Use your magnetic guides liberally here, they work wonders when forming angles. Also be sure that your surface is flat.
Step 3: Welding Individual Legs Together
Take 2 opposite sided legs and prepare to weld them up. Gather a stack of angle guides, and a friend! Use these guides to hold the legs in position, then tack weld them together.
Step 4: Going Vertical
This is the hardest part to get right. Gather a large heavy piece of plate steel, if you have one. I used 2 breaks from a sheet metal break. Have your buddy help hold the legs at perfectly 45 to the metal, and tack them to the piece. Alternatively you can use your metal layout table, but remember to be conservative with the tack so you do not damage the table.
Step 5: Final: Grinding and Finishing
Finish up all the welds. Remember if you suck at welding, there is always grinding! Start with a stone cutting disk. These are very aggressive, use them to grind down to just above flush. Finish up with a series of sanding, or flapper disks. Work your way up the grades from 60 to 120 to get a clean finish.
Some things changed from the final design. For one, the top angles were added later, as a better way to attach a heavy table top. `
I have no finished the table yet, I am debating whether to have it powder coated, finish grinding to a nice polish, or work with making a patina finish (Flame throwers sound like fun!)
Let me know what you think!