Plumb bogs are probably the most accurate method of measuring plumb over any appreciable distance. Use something accurately sized as a cross member at both the top and the bottom of the table/frame, such as drill rod or cast jig plate. You'll also have to have a room that is absolutely free of drafts. When you stand the table/frame up, adjust it's vertical so you have a 1/8 or so gap between the plumb bob line and the temporary cross members. Use a magnifying glass to accurately determine the measurement from the plumb bob line and the cross member. With care, you can easily (although its tricky holding a magnifying glass and using a mic) measure to the .001. Once you have the gaps measured at the lower end, use feeler guages to copy the measurement at the two bottom corners. The feeler guages will be the "pedestals" for flattening the JB Weld/Atomized Steel "pads" across the length of the table/frame rails so you'll have accurate mounting pads for the rails/rods. |