A Homemade Quick and Easy Plasma Cutting Table For About $20
It all started when I was visiting Jody, our Tech Editor, in Tucson, AZ and we were working on a few projects for the magazine. As we were hammering and welding away, he mentioned that if we had time that he wanted to make some American flags using his plasma cutter in a silhouette fashion. We never did get to that project, but it got me to thinking… Could I whip up some patriotic knickknacks too?
Before I got started though, I needed to make a plasma cutting table and being a Sunday afternoon, the chance of me getting a bunch of steel for the project was somewhere between slim and none. Using the scraps of steel I had lying around, I fashioned up a small plasma cutting rig that would be perfect size for whipping up small to medium sized projects.
You see, you can't effectively cut through metal when it is lying on top of a workbench or on your concrete floor. The plasma discharge and molten metal will fly everywhere and ruin your artwork, not to mention make a mess of the surface you are working on. I did happen to have some angle iron, so I whipped up a 21" X 24" plasma cutting table, perfect for small to medium sized project, and I'll show you how.
I started by figuring out how big I wanted my plasma cutting rig. My moveable work bench is 24" wide and 6' long, so I knew I wanted something that was as wide as my work bench. I also wanted it light enough and small enough that it would make it portable. Limited by the length of angle iron I had available, I settled on a jig that was 24″ wide and 21" long (the inside runners are actually 18" long, but the width of the outer angle iron is 1.5" wide, which makes the plasma cutting table a total of 21" long).
Knowing that I wanted my vertical inside runners to be spaced every 6 inches, I cut 5 section of 2" X 2" X ¼" angle iron 18" long. The outermost two pieces will serve as the outside edges of the box.
I then cut two longer, but smaller pieces of 1/5" X 1.5" X ¼" angle iron 24" long. These two pieces will serve as the top edges of the box.
Next, using some clamps and a large right-angle square, I setup the 4 pieces to serve as the perimeter of the box and tack welded them together.
I then spaced the inside three pieces of angle iron every 6" and tack welded them into place, again using a right-angle square to ensure everything was plumb and straight.
Once everything was tacked together, straight, plumb and square I laid in my final welds. You don't have to weld like crazy here, a few 1" welds on each piece will be just fine.
The last thing you need to do is take a sanding disc or sanding flapper wheel and remove the protective coating on the two, large flat top edges of the plasma cutting table, and on top of the vertical runners. Don't go crazy here, all you need to do is remove the protective coating and expose bare metal. This will allow you to place a ground clamp on the table itself, which will pass the electricity through the table and onto the piece that you will be working on.
A picture of the final plasma cutting table.
Now that I had my plasma cutting table all built, it was time to put it to the test. I set my plasma table on top of my workbench, fired up my plasma cutter, and then placed the ground clamp onto the plasma cutting table frame.
I then grabbed a piece of 1/16" sheet steel and started tracing out an image. Staying with the patriotic theme that Jody and I had talked about, I traced a picture of the flag raising at Iwo Jima. Using a fine point Sharpie marker, I carefully traced out all of the detail that I needed so that I could use my plasma cutter to cut out the shape.
I then lightly clamped it to the plasma cutting table rig to ensure it had good ground.
Carefully, I started cutting away with my plasma cutter, at times using another piece of angle iron clamped to the table to use as a cutting guide.
Here you can see what happens when the plasma discharge comes into contact with the plasma cutting table. A small notch will be cut into the table, but it will have no ill effect on future use. If you get a buildup of slag, you can use a grinder or a slag hammer to get rid of it.
Here is a picture of my final work.
I was able to put this simple, yet effective plasma cutting table together in under 1 hour using angle iron I had laying around the shop. I used about 12 feet of angle iron total, which originally ran me about $1.80 per foot.
The only thing I would have done differently is that I would have turned the two outside 18" runners 180 degrees so that the horizontal portion of the angle iron poked outwards, giving me 4 grounding points, instead of 2.
You might also consider welding thin gauge steel plate to the bottom of your plasma cutting table. This would protect your workbench and you could simply flip it upside down to shake the slag out of it.
In conclusion, the table works quite well on top of my workbench or on the concrete floor and provides ample capability to use my plasma cutter in a horizontal fashion.
Gee Mom, look what else I've found!
|Wisdom of my father: "It takes more of a man to walk away from a fight than to stay and fight."||