Working on a large kinetic sculpture last summer, I faced a problem. I had a bunch of strut sections that needed to be welded together. These would later be bolted into two giant, nested rings, so a high degree of precision was required. The strut sections were up to 1.6 meters long. I didn't have a welding table or any other reference plane nearly large enough to do the layout on, just a rough garage floor. How to alignment the sections to make sure they were in the same plane before welding?
My answer was to create adjustable height welding stands. With each section supported on 3 of those, I could carefully adjust the height up and down, until the entire thing was level according to a precision machinist's level. If I did that for both sections, they had to then be aligned parallel to each other. And since I figured these would be useful tools in the future, I put a bit of extra effort into making them really solid.
Step 1: Design
Most of the design was dictated by what I had on hand. I've given compete measurements here, but don't feel too constrained by them. There are only a couple of really important features you'll want to get right:
- Wide, low stance. Don't make them tippy!
- Solid legs (bar stock, not tube). The mass will get the center of gravity even lower, and will help prevent slipping.
- Rubber feet on the legs, also to help prevent slipping. These are available at most hardware stores in a couple of sizes. (1/2" and 3/4" are common in the US.) Match your legs to whatever you can get.
- Self-leveling furniture feet for the stands. Because they're self-leveling, the pad can twist a bit to make better contact with the piece being supported. This will help prevent slipping, and the nylon pads make sure it is non-marring. You can find these at hardware stores, but I always end up ordering them online for a wider selection.
- Plain steel nut (size matching whatever self-leveling feet you get) welded onto the plate. You can buy these at any fastener supply house, and you don't want to be welding a zinc galvanized or chromed nut! Health issues aside, the weld will be *terrible*.
Step 2: Result
The stands ended up working much better than I had hoped. They're simple and solid and reliable. I ended up liking them so much I bothered with a quick coat of paint. They're now part of my permanent tool collection. If I had to do it again, I would knock off the corners on the plate, or maybe go to the effort to find round or even hexagonal plate stock. But I'm not complaining. I smile every time I see them sitting around the shop, all squat and self-assured.
More importantly, the struts I made using them were precise enough to bolt together without too much swearing, which was really the whole point. Getting everything aligned took a lot of careful adjustments, 20-30 minutes per joint, so I wouldn't recommend it as a regular technique. But for that rare thing that absolutely, positively has to be as good as possible, it's great.