It is necessary to know and master the factors that affect the quality of the cut when using a metal laser CNC. Here we share a list of factors that can alter the cuts with CNC laser, so that you take note and it does not happen to you.


1. Choice of cutting speed

Cutting speed is a key factor in achieving a high quality end result.

If the cutting speed is too low, the cut will be wider, less precise, and rougher.

On the other hand, if the cutting speed is too high it can cause cutting failure with the sparks around it, the cutting section will be rough and some parts may not be cut completely.

The feed rate can be judged from the cutting spark. Sparks will diffuse downward in the normal cut, and when speed is too high, sparks will build up. In the event that the sparks do not spread but come together, this indicates that the feed rate is too low.

2. Effect of the nozzle

The air flow condition will be different according to the different nozzle designs, which will directly affect the cut quality.

The nozzle fulfills 2 main functions:

Prevents debris from bouncing upward and damaging the lens.
Helps control the area and size of auxiliary gas diffusion

Nozzle height

Take care that the mouthpiece is at a suitable height. The distance between the nozzle and the workpiece should be between 0.8mm and 1.2mm.

Too low a height can cause sheet metal and die to collide, and too high a height will cause gas to diffuse, causing a lot of debris on the underside of the cut.

Nozzle diameter

In general, when the nozzle diameter is small, the gas velocity is high and the melt removal capacity is strong. It is suitable for thin plate cutting, so fine cutting section can be achieved.

When the nozzle diameter is large, the gas velocity is low and the melt removal capacity is poor. It is suitable for cutting thick plates at low speed.

3. Selection of laser power

If the laser power is too small, the heat is insufficient, and the temperature of the molten product near the bottom edge is lower, and the viscosity is higher, so that the high-pressure air flow cannot completely expel.

If the laser power is too high, the heat input is too large, so that the melting range of the workpiece is greater than that which can expel airflow, so the molten metal is not removed by full.

4. Choice of auxiliary gas

Auxiliary gas can not only remove the slag in time, but also plays the role of cooling the workpiece and cleaning the lens. Different auxiliary gases can be used to change the cutting speed and the quality of the groove surface.

How to choose auxiliary gases?

5. Effect of ceramic ring

The ceramic ring is an important part of the cutting head of metal laser cutting machine. Its main function is to transmit the electrical signals collected by the laser head nozzle.

When it comes to the ceramic ring try:

Choose the gold plated copper needle ceramic ring. This will give you better signal conductivity during the cut.
Check the quality of the ring. The conical surface of the upper part of the ceramic body must have a high degree of smoothness and must not present any bumps or scratches.
Check the quality of the assembly. The stainless steel part must be closely attached to the ceramic body and there must be no elevation, deformation or space.
Always try to take these factors into account when making laser cuts on metal, so you will get top quality results and position yourself as one of the best on the market.