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Published at https://habr.com/ru/post/647743/
Nowadays, thanks to the Internet, you can find any laser system for business. An attractive ad lures a potential buyer to a website, but does good marketing and good reviews always guarantee that the product is exactly right for you? Expensive = quality? Cheap = bad? What to look for when choosing a laser machine? Let's figure it out.
The Aliexpress platform is gaining particular popularity for the purchase of laser equipment. The cost of an ordinary Chinese marking machine ranges from 120,000 to 500,000 rubles, and if you take a similar Russian-made system, the cost can exceed 1,000,000 rubles. And then a logical question arises - what's the point of overpaying?
— «Russian companies are just making money!»,
— «It’s better to trust the Chinese manufacturer, save time and money and not lose quality!»
It's not so simple. The choice should be based on the quality of its components and its actual capabilities. Next, we will look at some of them:
This, in fact, is the heart of the laser machine. Today we will look specifically at fiber lasers for marking and engraving. Why them?
Fiber lasers with a wavelength of 1.06 µm are the best tool for metal processing. The high absorption coefficient, the minimum focusing spot and the ability to transport radiation along the fiber to any point make it possible to leave other types of emitters behind when processing any metals. As you know, metals are the basis of industry.
A brief background of fiber lasers: at the end of 1998, the leading Soviet and American specialist in the field of laser physics and technology, Valentin Pavlovich Gapontsev, founded a well-known company that literally took over our planet. This company developed and introduced fiber laser technology to the industry, occupying 75% of the world market.
Valentin Pavlovich Gapontsev
Despite the fact that fiber lasers are the main product in the industry, there are not so many manufacturers of this technology, because, firstly, it is very expensive, and secondly, it is difficult to compete with the company created by Gapontsev. This luxury can be afforded by several leading countries, one of them is China.
However, it is important to take into account that the best modern Chinese fiber lasers are similar to Russian-made sources of a decade ago. Of course, not all Chinese manufacturers are oriented towards Russia, there are some who offer a lower price for lasers, but, other than a low price perhaps, Chinese manufacturers have nothing to offer.
The life of diodes with single emitters from the Gapontsev company exceeds 100,000 hours, which is many times longer than the service life of diode arrays.
Good laser emission is considered to be Gaussian energy distribution, when most of the energy is concentrated in the center. This distribution allows for the minimal size of the processing zone. At the Gapontsev company, the radiation source produces a small spot at the output, respectively, many photons are focused in one place, thereby the power density of the emitter is greater.
Gapontsev's emitters provide an output power of up to 100,000 W and the best beam quality at low energy costs.
For example, when processing copper (which is very reflective), there is a risk of burning the laser emitter, and repairing it in a service center is impossible - only the manufacturer can fix the problem.
The beginnings of the words are botched because the emitter does not have enough energy to treat the surface evenly.
Color Distortion Example
Now we will consider fiber lasers with scanning systems. Why them? Flatbed fiber lasers have not found a large market, so most fiber marking and engraving systems move the beam using deflection mirror scanners.
At the moment, the scanning system is the fastest option for moving the beam, the problem of this solution is that in optics everything is distorted, and the equipment needs to be configured correctly so that the beam movement is linear and accurate (a deviation of 20 microns is already considered critical).
Here is where the quality of the components becomes important. Almost all countries can produce mirrors and travel systems - unlike manufacturing fiber lasers, this process is not difficult. However, the production of mirrors is a very important element of laser system costruction, and the quality of this element greatly affects the operation of the machine. The scanning mirrors are coated with a film, which is important for reflecting emission from the mirror. If the coating is damaged or the mirror is uneven, the wave front of the laser emission is distorted, thereby the pulse is smeared, which affects the quality of the effect on the material.
Chinese systems often come with mirrors of different quality, due to which there can be a situation where the coating peels off and the mirror ceases to perform its functions. After all, if a mirror has poor-quality coating, then it cannot effectively reflect the beam, as a result of which part of the emission is absorbed, which leads to the destruction of the reflective surface of the mirror, thus it is impossible to operate this element in the system.
If mirrors with poor coating are put into the system with a power of more than 30 W, they no longer withstand emission, instead they accumulate it and cease to function a few months later. It is difficult to prove that the owner of the system had nothing to do with this, it is easier for the manufacturer to hint at his poor maintenance (the mirror can be “scratched”, “misused”, placed in a “dirty room” - the customer will always be at fault). There are responsible manufacturers, but it is important to know tham, which is not easy because there are hundreds of them.
An important point in machine tool building: the sum of the components of a laser system does not always guarantee a good result.
Let's take the automotive industry as an example. If we replace some elements on a Lada with an engine, wheels, or a gearbox from a BMW, we will not get a BMW. Manufacturing a complex laser system of high quality requires competence.
Some Russian manufacturers make optics and calculate optical channels themselves. Why?
The lens is the end node of the travel system, it consists of several pieces of glass. Each piece is a source of reflection, i.e., some small percentage of the light passing through the glass is reflected back (the better the glass, the less is reflected).
The lens has a certain curvature, and when reflected, the light can be focused. In an unfortunate scenario, a reverse glare appears, which will focus on the mirror.
Photo of a scanning head lens with a haze
The distance between the lens and the mirror must focus either before or after the mirror. If you screw in a lens that does not fit this optical path and expect everything to work, there is a huge risk of damaging some expensive element beyond repair.
In general, software is something that you can get used to, however, the Chinese manufacturer is not very interested in the convenience of it for a Russian enterprise.
For example, let's take any serious Russian company that needs to mark drawings from Compass, fonts or engraving according to GOST. Ez.Сad will never be updated to include the Russian design documentation, GOSTs and norms.
If we need to do a simple engraving, put a few characters on an award cup for the completion of the marathon in Times New Roman font, Ez. Сad will certainly be fine, and in this case it makes no sense to overpay.
However a modern laser system can be used not only for simple marking, but also can utilize additional axes, tables, linear travel systems, rotators, etc..
Ez.Сad can do some of the abovementioned things: some pictures can be marked on a rotator. But, if you want to create limbs and scales, and it is important to take into account a certain depth, relief or engraving shape when working with them, the quality leaves much to be desired. If the engracing requires particular dimensions when using the rotator (for example, the line width is 117 microns and the depth is 23 microns), doing it in Ez.Сad becomes very complicated and practically impossible.
By law, the manufacturer of laser equipment is required to give a warranty for at least 1 year.
Most often, a Chinese manufacturer that has sold laser equipment at a price of, for example, 600,000 rubles can safely give you longer warranty (with issues however). After all, the cost of equipment is around 300,000 rubles, repairs will require another 100,000 rubles, and the rest will go to the company's profit (and in a year you will already forget what kind of warranty you have).
Why do warranty issues occur?
Companies selling Chinese lasers have a high level of workload. Having sold a certain number of machines, they are constantly engaged in the repair and maintenance of their equipment. From a business point of view, this is good, especially when the warranty ends and you can cash in on the grief of customers. But, from the point of view of the consumer, you get what you pay for.
Technological capabilities of a laser system:
Laser systems of 2004 and 2022 do not differ much in terms of parts, but modern machines can do much more:
Marking photos:
Thus, a good laser system is not just a set of components, but a tool that implements the technology. You can simply assemble the components of the equipment, but teaching it the nuances of all technical points is impossible simply because you do not have the knowledge. After all, even ordinary laser engraving has many parameters: tone, depth, degree of destruction and impact, evenness of the edge, resolution, etc.
The low cost of Chinese equipment happens because the companies from China are in great competition with each other. Those companies that offer cheaper equipment oust those who are trying to sell more expensive, and possibly better equipment from the market. Cheap systems are in a better position, because it is easier to find someone to buy it, and modern sales methods allow any cheap manufacturer to say “it's the same, but without overpaying!”
This article was not written to dissuade you from buying Chinese equipment, but to show all the nuances and pitfalls of cheap machine building. If you have a well-established business, produce hundreds of products and want to get yourself a laser system that will ease your burdens, don't skimp on quality. Visit Russian manufacturers and for the next 50 years you will forget all your troubles with laser equipment, because there is always the opportunity communicate and study all the nuances. If you have only simple tasks for laser equipment, then Chinese machines are a good option, but remember that it is a lottery, and you will never be given a guarantee for the quality of elements, technical support and service. The choice is yours.
We would like to note that in this article we touched a little on the main components of the machine tool industry, comparing Chinese and Russian laser equipment. If you have any questions or you disagree with something, please, comment, so that we can correct our focus in the following articles.
It is important for us to be useful and interesting!
