Revisiting the Basics of Laser Cutting

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Revisiting the Basics of Laser Cutting
Laser, a technical word, is one of the most
common words which we have been using and
hearing for a long time. But, Did you know that
laser is an acronym for Light Amplification by
Stimulated Emission of Radiation? It is a byword
for efficiency and quality in materials
processing since its emergence in the
sixties. It offers an entirely new way of using
energy which helps manufacturing, medicine, and
communications. You can heat,
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• melt and even vaporize materials using lasers. It
  is an ideal medium for channelizing intense but
  controllable energy.
• But they are most popular for cutting.
• So, lets brush up the basics of laser cutting
  and its uses?
• Laser cutting is the thermal process that focuses
  laser beams on a particular area to melt
  material. It uses a coaxial gas jet to eject
  molten material and create a kerf.
• As the laser beam or workpiece moves continuously
  under CNC control, it produces a cut.
• There are three varieties of laser cutting
• Fusion Cutting
• Flame Cutting
• Remote Cutting
• Lets look at each in brief.
• Fusion cutting This cutting uses molten material
  to expel the kerf. Nitrogen gas does not react
  with molten material and as a result, it does
  not contribute to the energy input. It is
  advisable to use lasers with Trumpf spare parts
  and Fanuc spare parts for the best quality work.

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Flame cutting This laser cutting uses oxygen
along with other gases and exerts the mechanical
force on the molten material. This, in turn,
creates an exothermic reaction which increases
the energy input process. Remote cutting In this
laser cutting, the material partially evaporates
because of the high-intensity laser beam. As a
result, this cuts the thin sheets without using
any gas. You can use automation in the laser
cutting process using offline CAD/CAM systems.
It helps in controlling three-axis flatbed
systems or six-axis robots for three-dimensional
laser cutting. With the improvements in
accuracy, edge squareness, and heat input
control, the laser cutting technique is replacing
other profiling cutting techniques like plasma
and oxy-fuel. Lets look at the most vital thing
in a laser cutting machine which we tend to
forget easily. Yes, you guessed it right, we are
talking about the lens in laser cutting
machines. We often forget that lenses can affect
the thickness of the cut which is important for
the cut. So, lets understand how it works.
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• In laser cutting, you focus laser beams using a
  lens (sometimes a concave mirror) on a small
  spot where you need to produce a laser cut.
• One can define a lens by its focal length. And
  what is focal length? Its the distance from the
  lens to the focused point.
• There are two basic things which affect the
  efficiency of laser cutting
• Focused point diameter(d)
• Depth of focus (L) - Focal Length
• The effective distance which gives you
  satisfactory cuts is known as the depth of the
  focus. You can also define it as the distance at
  which the area of the spot doesnt increase
  beyond 50.
• These two things, depth of focus and focal spot
  diameter, depend on the raw laser beam diameter
  on the lens and the focal length of the lens.
  And on the spare parts you use. For best
  results, use Trumpf spare parts and Fanuc spare
  parts.
• Understand, constant raw laser beam diameter
  decreases the focal length of the focusing lens
  which results in smaller focal spot diameter and
  focus depth.

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• If there is a constant focus length lens then it
  increases raw beam diameter which reduces the
  spot diameter and depth of focus.
• To compare lasers with different beam diameters
  we use focus f-number, which is focal length, F,
  and then divide it by incoming raw beam
  diameter, D.
• There are two major requirements you need to
  consider for laser cutting
• High power density which focuses on small spot
  size.
• Long depth of focus to process thick materials
  providing a reasonable amount of tolerance to
  focus on position variation.
• But, the problem occurs when we realize that
  these two requirements are in conflict and you
  need to make some or the other compromises.
• Hence, you need to consider the fact if the focal
  length is short, then the lens would be closer
  to the workpiece which can cause damages to the
  lens during the cutting process.

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Wrapping it up It is necessary to understand the
basics of any machinery part before you buy it.
Because as an owner of that product you need to
understand why you are investing in that thing
and how even a small machinery part can impact
highly on your business. Also, make sure to
replace any worn out parts with only
high-quality parts like Trumpf spare parts and
Fanuc spare parts. This Article Post is
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