CNC laser cutter design

In summary, the conversation is discussing improvements to a traditional DIY CNC laser cutter. The idea is to increase the laser's travel or add stationary mirrors. The question is whether this will affect the output power and if there is a way to calculate this. The response explains that using plane glass without an anti-reflective coating can result in a 4% loss at each air/glass interface. This is why high power lasers use mirrors instead of lenses. Using an anti-reflective coating can improve this, but front-surface mirrors can be costly and difficult to clean. Adjusting the focal point may also be necessary.
  • #1
TL;DR Summary
How many additional mirrors and/or additional distance can I have in a laser assembly before I start seeing power losses?
I was thinking of an improvement to the "traditional" diy cnc laser cutter that might entail some extra travel for the laser and/or additional (stationary) mirrors. Is there some way to calculate how this will affect output power?

Many thanks in advance

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  • #2
Rule-of Thumb:
Using plane glass (uncoated), you lose about 4% at each air/glass interface.

That's why high power Lasers us mirrors instead of lenses, that 4% cracks the lenses.

You can do much better if using an Anti-Reflective coating for the specific light wavelength. Front-surface mirrors are a good option, but those can be pricey and difficut to clean without damage.

Beam distance thru air shouldn't be a major problem in itself, but you may have to adjust the focal point of the beam by modifying the optics.

Have Fun!

What is a CNC laser cutter?

A CNC laser cutter is a computer-controlled machine that uses a high-powered laser beam to cut or engrave materials such as wood, metal, or plastic. It is commonly used in manufacturing and fabrication processes to create precise and intricate designs.

What are the main components of a CNC laser cutter?

The main components of a CNC laser cutter include a laser source, a control system, a motion system, and a workpiece holding system. The laser source provides the energy for cutting, the control system dictates the movement and speed of the laser, the motion system moves the laser in the desired direction, and the workpiece holding system secures the material being cut.

What factors should be considered when designing a CNC laser cutter?

When designing a CNC laser cutter, factors such as the power and type of laser, the size and weight of the machine, the type of materials it will be cutting, and the desired precision and speed must be taken into account. Other considerations include the cooling system, safety features, and user interface.

What are the advantages of using a CNC laser cutter?

There are several advantages to using a CNC laser cutter. It allows for precise and intricate cuts, reduces material waste, and can cut a wide range of materials. It also offers high speed and efficiency, as well as the ability to automate the cutting process, making it ideal for mass production.

What are the limitations of a CNC laser cutter?

Although CNC laser cutters offer many benefits, they do have some limitations. They are typically more expensive than other cutting methods, require specialized training and software, and may not be suitable for cutting certain materials such as reflective surfaces or materials with high melting points.

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