Tmate
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- U.S. Maryland
Several years ago I mounted a 65 watt, air cooled Synrad laser on my plasma table. I knew 65 watts wouldn't cut steel, but was sufficient for cardboard, ceramics, leather, etc. I also wanted to test the mechanical accuracy of my table. These are the results:
The main differences between the results of the two processes are the variety of materials that can be cut with laser, the kerf width (gap cut from the material), and the lack of a bevel in the cut edge with laser. Cut smoothness is about the same in steel.
Plasma produces a kerf width of approximately .050" (1.27mm) - close to ten times wider than laser. This vastly reduces the amount of detail possible in a small area. An analogy would be comparing the detail possible drawing with a crayon vs. a ball point pen. This is illustrated in the photos below. The narrower the kerf, the greater the required mechanical rigidity. I found that while I could happily cut plasma cut steel at 60 to 70 inches (150 to 170 cm) per minute, I had to slow down to 1/10th that speed with laser. Any faster produced too much vibration, which showed up in the cut.
Another problem with laser is that while my 65 watt laser could be air cooled, the 1,500 watts or more needed for cutting steel requires water cooling. That introduces the complexity of running plumbing to moving components on the machine. Of course, there is the cost element, with laser being exponentially more expensive than plasma.
The photos below show the machine I used. While this one was indoors, it was mechanically identical to one I was using in my shop. Also shown are identical pieces I cut as small as possible with plasma and with laser. Another photo shows some motorcycle shapes I cut with a small plasma table, and identical shapes I had cut by a laser service.
In deciding whether either process is worth the expense and bother, it is necessary to look at the alternatives. The motorcycle shapes would have been impossible with any other process (excluding water jet). While a band saw with a blade welder could cut large radius brackets, etc, it would be far more time consuming. A milling machine would take even longer, although more precision would be possible. The motorcycle shapes required about 3 minutes cutting time to fall from the plate. A simple bracket of similar size maybe 45 seconds or so. Bolt holes can be laid out in a Cad program in the same or less time than with the DRO on a mill.
These are just a few thoughts for those contemplating the purchase of such equipment.
The main differences between the results of the two processes are the variety of materials that can be cut with laser, the kerf width (gap cut from the material), and the lack of a bevel in the cut edge with laser. Cut smoothness is about the same in steel.
Plasma produces a kerf width of approximately .050" (1.27mm) - close to ten times wider than laser. This vastly reduces the amount of detail possible in a small area. An analogy would be comparing the detail possible drawing with a crayon vs. a ball point pen. This is illustrated in the photos below. The narrower the kerf, the greater the required mechanical rigidity. I found that while I could happily cut plasma cut steel at 60 to 70 inches (150 to 170 cm) per minute, I had to slow down to 1/10th that speed with laser. Any faster produced too much vibration, which showed up in the cut.
Another problem with laser is that while my 65 watt laser could be air cooled, the 1,500 watts or more needed for cutting steel requires water cooling. That introduces the complexity of running plumbing to moving components on the machine. Of course, there is the cost element, with laser being exponentially more expensive than plasma.
The photos below show the machine I used. While this one was indoors, it was mechanically identical to one I was using in my shop. Also shown are identical pieces I cut as small as possible with plasma and with laser. Another photo shows some motorcycle shapes I cut with a small plasma table, and identical shapes I had cut by a laser service.
In deciding whether either process is worth the expense and bother, it is necessary to look at the alternatives. The motorcycle shapes would have been impossible with any other process (excluding water jet). While a band saw with a blade welder could cut large radius brackets, etc, it would be far more time consuming. A milling machine would take even longer, although more precision would be possible. The motorcycle shapes required about 3 minutes cutting time to fall from the plate. A simple bracket of similar size maybe 45 seconds or so. Bolt holes can be laid out in a Cad program in the same or less time than with the DRO on a mill.
These are just a few thoughts for those contemplating the purchase of such equipment.
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