CNC plasma tables are virtually everywhere and are the most economical tool for basic sign shop metal cutting.

Computer technology has changed the cutting end of sign shop fabrication completely. Many commercial sign companies, even some small ones, have their own CNC router table, or if not, sub out that work or may hire a waterjet service provider to do high-quality cutting of a variety of substrates. But another workhorse of today’s cutting technologies is the CNC plasma torch table, an economical tool for some of the basic types of metal cutting, especially steel cutting, needed by today’s sign fabricators and installers. For cutting ferrous metals at fast speeds and low cost, it’s simply hard to beat.

 

In the past, I have been guilty of hiring out waterjet work to cut items we needed for sign shop fabrication when a plasma table would have worked just as well and would have cost a lot less. Generally speaking, the cost to hire an item cut on a CNC plasma table should be roughly half the cost of waterjet cutting, and for structural parts and basic steel cutting, the quality and accuracy of the cutting should be just fine. And there are a lot of plasma tables out there, which means finding a local provider of this type of CNC cutting should be fairly easy just about anywhere in the country. 

 

For steel cutting, a plasma torch uses compressed air and a high-voltage electric current to create the electric “torch flame” it uses for cutting, and the only real consumables used are inexpensive cutting tips and electricity. Though with the right tips and different gases, a plasma torch can be used to cut aluminum, it is primarily used to cut steel and do it quickly.

 

Sign base plates, braces or gussets and other basic steel items are ideal for plasma cutting, but we also have designed a few special sign items for our customers that can be cut this way. One of these is an ideal round base sign system for temporary or portable signage. The parts drawing for this item is shown here, and we typically cut the circle by cutting four sections so these parts can but cut in a 12" x 18" rectangle, or be re-arranged and cut in void areas or scrap pieces of plate steel that had been used for a larger project. We also have it as a complete circle with the extra parts inside, but the broken version is easier to fit anywhere and can be cut from areas of sheets that otherwise would be scrap.

 

 

If there are items that you should be stocking, such as parts for a special sign system, or just rectangular base plates, triangle braces, and so forth, you may be able to provide a CAD drawing (normally .dxf file, or even an .ai file) to your local plasma table operator, and give them opportunity to cut some for you when they are cutting something else, even in void areas of larger cuts.

 

In our case, we sub out our plasma cutting to our sister company, WPC Services, which is across the street and, of course, handy for us. But, even if we were going to another local vendor, giving them these options would still be a good idea.

 

Because plasma cutting is one of the least expensive types of CNC cutting, especially cutting steel, it is ideal for some types of sign related jobs that would not be that practical any other way. One example is the small trophies we have made on several occasions for mostly oilfield related tournaments, produced fast and cost effectively when cut on a plasma table. They look like little oil derricks, which may be varied slightly for different themes, with the derrick part welded to a small round cornered rectangular base. Cut from 1/8" steel, welded together, then powder coated, they seem to keep being in demand. And in a recession, adding special items to what we normally offer our clients, does not damage our reputation one bit.

 

 

Similarly, there is a local company we do contract work for that makes many hundreds of address signs, welcome signs, and other yard items economically cut on a plasma table, all of which have a canine theme. They stock the shapes of dozens of breeds of dogs, and sell these items all over the country. Their cost to cut all these shapes is really a small part of the cost to make these items, since the plasma cutting of nearly all their items averages between $1 and $2 each.

 

Most standard types of plasma tables and plasma torches will cut mild steel from 18 gauge (less than 1/16" inch thick) to 3/4" or 1" thick steel. This range of thickness covers virtually all the steel cutting most commercial signs shops get into. The one thing a sign maker does not want to do is to hand cut items using a torch, metal saw or drill press, if the part would best be done using a CNC plasma table. 

 

The cut produced by this type of torch, however, will leave a little slag and will generally need a small amount of clean up with a grinder or flap-wheel sanding disk. Precision will be within a 1/16" or so, not the .005 that a waterjet might deliver. Just the same, for a lot of the cutting required by commercial signs shops, these limitations are not really a big concern. And even the small stuff, at least decorative items not demanding the accuracy of a waterjet, can be handled quite well with a plasma system. 

 

Whether shop-owned or subcontracted, a CNC plasma system can be a valuable tool to most any commercial sign company. In most areas, if it is not in your shop, it’s probably just down the road, because there is a plethora of these cutting systems in service these days. Being able to use this technology to expedite fabrication jobs or tackle special projects that require a lot of cutting can be a real asset to the signmaker, and the very reasonable cost of this service should be an asset to the signmaker’s bottom line as well.