If this is going to be used in a small shop/garage shared with other tools, vehicles and humans you need to understand how incredibaly nasty and dirty plasma cutting is. You are vaporizing steel and other metal and it turns into smoke and a fine abrasive (and conductive) dust that gets EVERYWHERE!
Better consider aggressive dust extraction on any design. About the only thing that is fool proof is having the table in it's own sealed room!
I didn't look at the design but you might want to consider an "A" frame approach (somewhat like a panel saw) where the material is put on the table at about 15 to 30 deg from vertical. There are a lot of forces involved in slinging the head around and you can get some interesting vibrations and flexing in framework. |