Checking The Focus on the Laser

What is Focus?

When the laser beam come out of the laser tube, the diameter of the beam is approximately 6 to 8 inches in diameter.  At this point the power of the beam is spread over a wide area.  The lens concentrates the laser beam to a point that is approximately .003.  This point is where the beam is at its strongest.  This is just like taking a magnifying glass and focusing the suns rays on an object.  The sun itself emits heat which you can feel when walking outside.  But taking a magnifying glass and focusing the suns rays on a piece of paper will concentrate the rays and eventually burn a hole in the paper.

Focal length is determined by the lens on the laser.  Our lens have a 2.5 inch focal length.  This means that 2.5 inches from the bottom of the lens, which is where the beam comes out, the laser beam is at its strongest concentration.  If the material is exactly this distance from the bottom of the lens then the engraving quality will be as it should.  If the lens is out of focus, or not at the 2.5 inch mark, then the engraving quality can suffer and the power will not be as great.

Manually focusing the laser

1. Using the Table Up and Down buttons, raise or lower the table  enough to prevent the focusing tool from hitting the lens (Figure 1).

2. Slide the focusing tool directly below the outer edge of the aluminum ring supporting the lens.  Let the top end of the focusing tool rest up against the side of the aluminum lens support.   (Figure 2)

3. Using the "Table Up and Down" controls, carefully drive the table down until the focusing tool clears the bottom of the lens. The focus tool will free itself from the edge of the lens and rock back and forth slightly.  The focal length has now been set! (Figure 3)

4. Remove the focusing tool from the laser and close the lid.