If you keep having quality issues or problems with your laser then you must read this article.
By Marco de Groen, The Netherlands
It all started after I first got to work with a GCC laser cutting and engraving machine during my design study at school. The machine proved to be a great tool for creating amazing fancy and high-quality products on wood and I fell in love immediately. After moving from Holland to Malaysia I decided to start my own laser business there. Cutting and engraving on tropical high-quality wood proved to be a booming business, which many people were interested in. But purchasing and setting up the machine all by myself proved to be more difficult than I thought. There are many factors to take note of and I had to learn the hard way by facing all these problems myself and try solving them.
After using the machine for almost 2 years all by myself I found out there are many factors people are often not aware of when purchasing a machine like this. Since these factors can cause many serious problems and consume a lot of time I wanted to write this article to help out others around the word. These tips can save you a lot of time and headache and will improve the quality of your laser business. Also, I felt that there are still very few articles online that mention these issues while they are very important.
The tips vary from machine purchase and usage to file usage, materials, and laser setups. So here they are:
1. Make sure you do proper research on machines, suppliers, and your own business
Laser machines are a big investment and each laser brand has its own machine types. The machines have different sizes; powers and functions so make sure you know what you want to use it for. Some machines are more suitable for production while others are not since they are much slower. Bigger machines allow you to cut and engrave bigger items, so make sure you figure out first what you want your machine to do.
Also, do your research on suppliers and distributors of the laser machines. Find out which companies get good feedback and how fast and how much the spare parts will cost you should you purchase a machine from them. I made the mistake to buy the machine from a supplier who did not keep a good stock of spare parts. So when I needed something to be replaced I sometimes had to wait 2 up to 3 weeks to get my parts delivered to me!
2. Setting up your laser in your company
The first crucial thing to take note of is the humidity of the country you are living in. For example, Holland has way less humidity than Malaysia and because of this the compressor and air system for the machine needs to be totally different. I will tell more about this later.
Figure out the location of the machine in your company aswell. Cause what if the machine needs to be replaced, or you want to sell it? Will you still be able to move the machine out easily? This is something to keep in mind. Also, make sure your power supply (and power plugs) are sufficient since you need to install more equipment such as the machine itself, a compressor, an air filter, computer, suction, water drainage and more. Another thing to keep in mind is that the room with the machine in it should be dust free and also be cooled with an air conditioning if possible. This since the machine will generate a lot of heat.
And last but not least make sure your machine needs or has and earth electric cable connected. This since most laser machines generate their power in an electric laser tube. This tube needs to be released of its electric tension. Without an earth cable the tension on the laser tube will cause it to break within one year.
3. The Compressor is Crucial
Each laser machine needs to have some sort of compressor (air support). The knowledge and experience of your distributor’s technician are crucial in this part. What type of compressor you need depends on and several factors such as the humidity, the laser, the size of the laser and the power (60W up to 200W and more).
Your technician who is sent by the distributor, which you bought the machine from, should always be responsible for setting up the machine including the air support, suction, and drainage. This since they are the only ones who know what the right setup is for their machines. Make sure they will do this for you.
Due to the extreme humidity in Malaysia my machine needed a different compressor than the machine that I used in Holland (more dry air). But since the air was so humid we also needed an air dryer and cleaner. Now this is the most important part of all. You must be 100% sure that the air blown into the machine is clean and dry! This since some compressors will still have oil and water in the air they produce. Oil and water are your machines number 1 enemy. The oil and water will blow out at the laser head and will stick on the lens. The result will be that the lens turns blur, your laser work will turn ugly and eventually the laser beam will burn a hole in the blurred lens. And since the lenses are quite costly this should be something to avoid at all time!
At the above image you can see the laser lens contains water drips and oil. A sign the compressor needs a water dryer and oil filter.
Should you be doubting whether the air at the laser head is clean try to put an A4 paper underneath the head while letting the compressor run. Dirt marks like this show the air is not dry and clean.
4. Automatic Water Drainage System
When living in a relative humid country your compressor will exhale a lot of water. This water will be stored in your compressor or an air compressor tank. You must empty this water storage daily or even hourly depending on your humidity. So for some countries, it might be handy to install an auto drainage system on the compressor or air tank. This device will automatically empty the water storage so it will never get full. In this way, you also can keep the machine running without you needing to be there to empty the water tank constantly. It’s not necessary but for sure very handy when you have assignments that take very long and the device also is considered a small investment.
5. Amount of Air Support during usage
When using your machine you need to regulate the air support. Cutting and engraving are very different in power so the air support for cutting always needs to be higher than when you are engraving. If the air support during cutting is not high enough your materials will catch fire. Should this happen directly pause your machine and turn the air support higher. Before you continue you must make sure that the fire is all out.
At the above image the machine does not have enough air support during cutting. The result is a large flame coming out of the laser head.
6. Air suction and Air flow
As mentioned earlier the materials might catch fire when the air support is not sufficient. But depending on your air suction in the laser machine the fire should always go out by itself. Of course, your distributor’s technician should also install the air suction.
The air suction makes sure all smoke and oxygen are removed while you are working with the laser. Smoke will cause the lens to get dirty and oxygen will let your wood catch fire when you are cutting. It is very important to have an air suction machine that is powerful enough. Also, the exhaust should be installed at a suitable place outside. You don’t want your neighbors to be enjoying all your smoke after all. Make sure all suction pipes are sealed well. Open spaces will weaken your suction and will make the air suction less efficient.
The above image shows a malfunctioning air suction. The result is too much smoke stuck in the laser chamber.
7. Making small objects? Then a Honeycomb is necessary
Should you be cutting and engraving rather large objects with the machine then the standard metal strips on the machines working area should be sufficient. But if you start cutting objects smaller than A3 size then a honeycomb is necessary. The reason for this is that without a honeycomb the objects might not fall down to the bottom of the machine after they have been cut out. The result is that the objects might stand up and form a huge risk for your laser head to bump into. These type of situations could cause serious damage to your machine.
When small items stick up, they could cause serious damage to your laser head.
Personally, I prefer to always use a honeycomb in the machine. It is another big investment since the honeycomb usually costs around 1000 euros, but it is worth it. Not only can you let the machine run by itself without needing to check for upstanding objects. Also, the machine will not laser through the material directly in your machine bottom plates. I used the metal strips for these 2 years and the bottom plates of the machine have been completely burned black and ugly. It is not a pretty sight I can tell you, though the metal plates should have no problem to handle the laser beam burning into them.
This is an example of what a honeycomb surface looks like.
8. When cutting try not to place other surfaces or objects underneath the object to be cut.
When you are planning to cut a certain material with your machine please try to avoid placing any type of objects or surfaces underneath the material for support. The reason is that the laser beam needs to able to cut through the material without anything blocking the laser beam on its way through. Should anything be blocking the beam then the material you are cutting will turn black or even get burned on the bottom for the simple reason that the heat is not able to escape.
9. Knowing your machines lenses and when they are not working properly.
Since the lens of the machine is the most crucial part you must make sure it is working well. Any wrong setting or problem with the lens will make your product quality less. Also, it will cause you problems that eventually will damage your machine or the lenses itself. So how to recognize problems with the lens?
First of all, your distributor’s technician should always help you with the setup of the lenses and if anything is wrong with the lenses he should be the one to correct the setup. This cause the lenses are quite expensive and if you do anything wrong with the lenses you might end up losing your warranty on the lenses. So how to know if something is not right?
Personally, I always advise cleaning your lenses daily with the tools supplied by the distributor but weekly should be sufficient as well. On your laser machine, you should always have a red laser dot visible. This red dot acts as your marking/starting point. But most importantly when it turns blur or vague it acts as a marker for your lens quality. If the dot is not clear or sharp after you cleaned all the machines lenses then it is most probably caused by an incorrect setup or angle of the lenses.
Examples of what will happen when your lens is dirty or not set up correctly.
When you clean the lenses and you notice extra lines or poor quality of your cutting and engraved products then this means the lenses are once again not set up correctly.
If at anytime you experience a lot of smoke or a burning/glowing lens inside the laser head then please stop your job immediately. Continuing the job will result in damaging your lens or even burning a hole in it. Usually, this is the result of too much dirt on the lens or a wrong reflection of the laser beam by the lenses.
An example of the lens inside the laser head glowing intensively. Should this happen to your machine stop immediately and contact your supplier.
Should there be a lot of dirt or even moist/water on the lens then you might want to look back to point 3 about the compressor. Usually, a bad compressor setup is the cause of this.
Last but not least always make sure that the distance between the laser head and the material is sufficient. Should there be not enough distance then the heat can’t escape well enough and this will result in damage to the lens as well. Usually, the machine is equipped with an auto-focus or a small measurement tool.
Here is an example of the laser lenses not aligned correctly. As a result, the laser beam is reflected in multiple beams. This will cause extra lines and reduced power when cutting.
10. Know your material and think ahead
Especially for wood, it is always good to know where you can get good quality wood. Tropical wood like Meranti, Merbau, Teak etc. always will have a certain standard, which is good enough to use for your laser. But when it comes to cheaper factory made wood like MDF or Multiplex please make sure you check the quality. Often the multiplex wood or MDF consist of holes which you only will discover after your laser burned away the top layer.
When using natural wood you need to look out for grains and knots in the wood. This since the laser effect will turn out different on those. This is caused due to different hardness and structure than the rest of the wood.
Should your wood not be completely flat after you stored it you can try putting some weight on it and let it rest for one day. When engraving or cutting wood it should always be as flat as possible this to avoid differences in engraving or cutting quality due to variation in distances of the wood from the laser head.
Before you use a certain type of wood always run several tests on it to see how the wood reacts to the burning heat of the laser. Some woods might have juices coming out which will stick on the wood after engraving or cutting it. In this case, you might want to use masking tape. Read more about masking tape later in this article.
11. Laying your objects straight in the machine
When you want to engrave on an object that needs to be absolutely 100% straight I often use extra objects to lay down in the machine. U just need to make sure that the objects are flat and straight. In this way, it is easier to make sure that the artwork will be engraved or cut straight onto the material.
Anything straight and flat can be used to align abjects in the working area.
12. The usage of masking tape
As mentioned before by Geordie at Instructables using masking tape is a great tool to avoid smoke and burning dirt on your wood. But I personally am not a great fan of it. The reason is that out of my own experience I have encountered a big quality problem when using masking tape. First of all several masking tapes tend to melt or leave a nasty sticky layer on the wood. Also, several masking tapes proved not to be sticking well enough to withstand the blowing power of the air support. So it would be blown off long before the machine finished the job.
But the most important reason for me not to use masking tape is for the fact that the layer of masking tape on the material will affect the quality of your artwork burned onto your wood. On the image attached here, you can see one example of a small detail engraved onto wood with and without masking tape. The difference is quite big as you might see, and I am using the same power and setup on both occasions.
After you have engraved your wood without masking tape my advice is to wash the wood with water. In this way, you can clean the surface of dust and dirt and you can clean the object. If some dirt is stuck on the wood you can also use a light sponge to scrub off the dirt from the wood.
Only when you are using MDF, which cannot get wet or wood that has many fluids/juice that come out I would advise the use of masking tape.
Left is without masking tape, right is with masking tape.
13. Keeping your own laser guide
When you cut and engrave a lot of different materials it is always handy to keep track on your settings and save them on your computer. Normally I place these setting in a word file and I save the settings as different profiles in Coral Draw.
14. Always make mock-ups and tests
Should you make large objects or construct things together then it is always a good choice to make mock-ups and tests of the objects first. Materials and designs always come out more different then you expect. So it is always good to see the object in 3D first.
Also, it is good to run some tests when you are cutting objects that are small. Distances in your design files often turn out very different then when your laser cuts them out. This since there is a difference of around 2mm (thickness of the laser beam) in each cutting line.
15. Preparing your files
The way you set up your design files in Illustrator will decide how the machine reacts and in which order it will laser the design itself. First of all, it is wise to always work in layers and place the designs in the same color schemes as Coral Draw does. Engraving usually is black, cutting lines are red, and other lines are green. But of course, you can give your own colors as well just make sure you group everything in the same colors in Coral Draw.
Most important of all is to make sure your design file is clean! Remove useless lines, anchor points, double lines and anything else that is of no use.
The reason for this is that even though you won’t select the objects or give a setup to it, the machine will still see it and hover over the objects in the file. Without all the useless objects in your file, you can save a lot of extra time.
Example of a design file with 3 different layer colors.
16. Raster or vector
So the big question when you engrave with your machine is raster or vector?
The biggest difference between these 2 is TIME! Raster objects always take a lot longer to engrave then vector objects. The reason for this is that raster objects are engraved like a printer that prints out a page with ink while a vector object is a line that is followed exactly by the laser head in a faster speed. This will save you a lot of time as described by Georgie at Instructables.
So if you want to save time and the design you want to engrave is suitable for it, always use vector. Do you want a more detailed result with a bigger and more detailed design then raster is a better option. When it comes to text and engraving my tip is to make a vector outline around your text as an extra detail to make your text pop out. You can find more information about this technique here.
These are all the tips I would like to offer to you all. I hope they have proved to be useful. Should you have any further questions then please do not hesitate to contact me. I would be happy to help out or explain some points more detailed. Laser brands I highly recommend are Trotec, Universal Laser, Epilog and GCC.