Is Accuracy and Repeatability Important to You? It Should Be!
If you really want to know how accurate a CNC shape cutting machine is, test it with a laser. CNC plasma-arc cutting is great for most metal fabrication jobs. It's fast, economical, and accurate enough for most metal cutting needs.
However, due to the .060" to .070" kerf (gap) plasma leaves when it makes a cut, the amount of detail it can create is limited by the size of the shape being cut. The bigger the shape, the more detail plasma can produce.
The moose scene in the photo to the right would have to be at least 15" wide to cut it out of metal with plasma. The eagle & flag would have to be close to 13" x 13". Most moderately priced CNC cutting machines can handle that, more or less.
It is impossible to determine just how accurate a CNC cutting table is by looking at plasma-cut pieces, no matter how intricate they might appear to be. It is only through the use of a process like a low-power laser, which leaves a gap only 3 or 4 thousandths of an inch wide that the real accuracy of a machine can be determined.
Why is such accuracy important if all you want to do is plasma cutting?
Just because a 2,000 watt laser powerful enough to cut steel plate costs over $100,000, don't overlook the many operations your CNC cutting table can do with a lower power laser. Metal cutting comprises maybe 5% of the operations that are possible with a computerized X-Y axis table.
Those of us who are metal fabricators sometimes think of the industrial world exclusively in terms of metalworking. We don't consider mounting a laser on our CNC cutting table because of the cost of a laser powerful enough to cut metal. Step outside the box and consider other possible uses of your CNC machine. Who knows what new applications your growing business may tackle over time?
There are hundreds of kinds of work that can be done on a Torchmate X-Y cutting table with a 10 watt laser. Such lasers are available for about $4,000. The paper cut-outs and gaskets shown here were cut at about 5 watts. The leather engraving was done at about 7 watts. The leather cut-out and ceramic engraving was done with a 25 watt laser costing approximately $7,500.
Above: Moose scene 2 3/4" long
Above: Patriotic shape 2 3/4" x 2 3/4"
Above: Miniature gasket is smaller than a nickel.
Perfect small holes are .046" in diameter, and were cut with lead-ins and lead-outs .020" long.
Above: Leather coaster, laser-engraved & cut.
Above: Paint any paper gasket black & scan it. Create as many duplicates as you want.
We have designed the necessary accuracy into our Torchmate 2 and Torchmate 3 machines to enable them to use a wide variety of processes. Don't make the mistake of selecting a machine that can do only one thing.
Above: The same Eagle head/flag design shown above, but laser-engraved in ceramic tile.