In this post we look at how accurate laser cutting can be for laser cutting metal.
The laser has numerous applications within industry and the technology has even become adopted by hobbyists and crafters who often operate lasers from home or small office units. However, this post looks at how accurate laser cutting is within the sub-contract sector that GF Laser operates within.
The main area to consider is tolerances, GF Laser generally offers tolerances of plus or minus 0.25mm so in practice a hole specified at 5mm could be within the range of 4.75mm to 5.25mm. This tolerance is generally accepted for most forms of accurate laser cutting. However, GF Laser has had success in holding tolerances of + / – 0.08 mm when cutting specialist parts for the aerospace industry. This is generally only achievable with fiber lasers and on thinner material up to around 3mm.
In addition, when customers require highly accurate laser cutting they will also specify a top or bottom limit tolerance. For example, a 5mm hole cannot be smaller than 5mm but can be bigger than 5mm by up to 5.5mm. In this instance the CAD team at GF Laser would usually programme the hole at 5.25mm offline and then the operator will undertake numerous checks at the machine to make sure the hole meets the requirements.
Material thickness plays a big part in how accurate laser cutting can be. GF Laser cut up to 20mm thick in mild steel, this takes large amounts of laser power and there is more heat build up when compared to laser cutting thinner materials. In turn this means that laser cutting will not be as accurate in thicker material. The way the laser focuses on the material and then as the light dissipates is also more pronounced in thicker materials due to the longer distance travelled. The diagram below illustrates how the laser beam alters shape as it moves through the material.
Positioning Accuracy of Laser Cutting
The laser cutting machine also has a positioning accuracy tolerance. This will affect, for example the distance between one hole and another or the distance from a hole to the edge of a part. The manufacturers of our laser cutting machines Trumpf indicate that the machines will operate on a positional accuracy of +/- 0.03mm. Therefore, it can be seen that tight tolerances on features relevant to each other shouldn’t be a problem for most laser cutters.
If you have any specific enquiries on laser cutting accuracy then please feel free to contact a member of our team by filling out our contact form.