I know its a bit early to be thinking about how to stay COOL in the sun, but the shortest day of the year is only a short time away. Before you know it we'll be plowing, mowing, cultivating and of course, sitting on a tractor in a parade, waiting for the line to move and sweat will be running down your....well, you know. In anticipation of that, I thought I might like to add an umbrella to my cubs. I usually drive the larger tractors which already already have them and I hate watching the kids sweat while I"m under shade. Here's a simple solution.
The base is 3/8" plate adn the tubing accomodates a standard 1 1/4" steel umbrell pole. I thought about using round tubing, but I found that the square tubing actually fit better, and was much easier to weld a nut to in order to accomodate an "L" shaped set screw which allows you to hand tighten it to secure the pole.
I've got both the "hook type" umbrella, where the pole has a big arm that comes around on the outside of the umbrella and hooks to the top, and the type where the pole goes straight up through the umbrella. The latter seems to work best, as shown.