Glued Lens Tubes
The glued lens tube is similar to what premium machine builders, such as Epilog and Trotec, use in their machines. It will allow you to realize the full capability of your machine by mounting the lens in the best possible conditions, making the lens easier to clean, and maintaining the correct focal point for years to come. For more information on how to purchase and install a glued lens tube, scroll down.
Click on an Image Below to Purchase a Glued Lens Tube:
How to Purchase a Glued Lens Tube:
Two pieces of information need to be known in order to select a focus lens: 1.) outside diameter of existing lens tube and 2.) desired focal length.
Determine the outside diameter of the existing lens tube. Use a digital micrometer to measure the outside diameter of the lens tube, below the knurled thumb nut. A digital micrometer will ensure you select the correct tube since the sizes differ by 1mm increments.
Determine the desired Focal Length. Laser quality lenses, are available in various Focal Lengths based on your needs for engraving and cutting. Below are four popular Focal Lengths for CO2 lasers. Most lasers ship from the manufacturer with 1.5" or 2.0" because they are fairly universal.
1.5" (38.1mm) Focal Length - smaller spot size, ideal for up to 600 dpi detailed engraving and fine cutting less than 2mm.
2.0" (50.8mm) Focal Length - multi-purpose, suitable for most applications, for 500 dpi engraving and cutting from 2mm to 5mm.
2.5" (63.5mm) Focal Length - excellent cutting lens, for 400 dpi engraving and cutting from 3mm to 15mm (depends on laser power).
4.0" (101.6mm) Focal Length - used for cutting thicker materials, larger spot size, for 200 dpi engraving, engraving of curved surfaces, and 7mm and greater cutting (depends on laser power). Lasers under 100W may not see much benefit from this lens.
These are suggestions not rules. The cutting ranges below are based on a single pass. Your results may vary depending on your alignment and your lens quality.
This video from American Photonics does a nice job explaining the different focal lengths: Glued Lens Tube Focal Length Comparison.
A quick note about DPI: A .005" spot size fills completely at 200 DPI, and a .003" spot size fills at 300 DPI. For comparison purposes, the APC 2" Mencius lens has a .002 spot size and the 1.5" Mencius lens has a .0015 spot size.
How to Install a Glued Lens Tube:
Install per manufacturer's instructions.