THE RIGHT LASER SOFTWARE

DO SOME CHECKING TO MAKE SURE THAT YOU’RE NOT BUYING SOMETHING THAT WILL SOON BECOME OBSOLETE

In the previous articles of this introduction to laser cutting and engraving with domestic and DIY devices, we have explored the key aspects of the tool: laser power, materials, cutting thickness, and use of the Z-axis.

The use of the laser machine is fast growing as a good and cheap alternative to 3D printing technology for some types

of tasks. The mechanics and electronics of domestic laser tools are relatively easy to manage and maintain, with fewer issues than 3D printers, but the most painful issue is the software. I started writing on laser technology more than six months ago and the software options currently available today are almost the same. Finding the right software is a key factor to achieving good results.

Lack of choice

Chinese producers do not deliver good applications with their machines. Almost all domestic 3D printers, as well as most of the assembled commercial ones, are compatible with (at least) the popular Cura or Repetier programmes, released as open-source.

For laser machines, the only available software compatibility is with Grbl code.

Based on the universal G-code language adopted by most of CNC machines, Grbl software is an opensource programme designed to control moving machines. There are plenty of CNC routers, 3D printers, and lasers with microcontroller boards that include a version of the Grbl software as the jobcontrol firmware.

The problem is that Grbl is a low-level programme and we also need a user interface to manage the graphic designs to send them to the tool. Without a user application with a good interface and graphics features, our laser tool is useless.

Avoid this software

Digging on the technical forums, all you can find is a version of the Benbox software. I used it — or tried to use it — and I strongly advise you not to download and install this application.

It is full of bugs and, even worse, it is no longer supported by the developers, and it is a primitive application designed to run on Windows XP (no longer available). Basically, all you get is a

crashing application with unstable USB drivers and if you try to install it on a Windows 10 computer you risk serious damage to your system software.

You can buy commercial laser programmes, but they’re expensive and almost all are specific for branded, highpriced laser tools.

Before deciding on what sort of software is right for you, it is important to check the compatibility of your hardware.

When I choose a hardware tool, I make sure that the system is compatible with a communication protocol and drivers based on a standard. Changes happen over time and technology evolves fast. One of the worst issues, which is not difficult to avoid, is adopting a non-standard system. Before you know it, you may find that the software or hardware company has stopped producing or maintaining its products. The system becomes obsolete.

Staying independent

If the laser tool is based on the G-code protocol and the open-source Grbl firmware you don’t need to depend on the producer. I chose the software for the last cutters and engravers that I bought with this scenario in mind. After testing different applications I found two of them are worth experimenting with and using.

The first is T2Laser, a versatile system that works very well with many different laser platforms, as well as small CNC machines.

The second, which we will cover in detail in the next issue of

Basically, all you get is a crashing application with unstable USB drivers

The Shed, is Laserweb. T2Laser is a commercial application sold at a very affordable price; it has been created and maintained by a single developer, Zax, who I have had the opportunity to know virtually. His development approach is reliable as he has a very good technical background.

Experimenting with a low-power laser

We have already analysed the most important factors involved in laser cutting, as well as the limits and possibilities of a relatively powerful home laser cutter for making technical components.

Now we will try working on a less powerful machine — one of the cheaper and popular laser heads: a 500mW laser with a surface of about one sheet of A3 paper.

The most costly component is the laser head, so low-power machines can be relatively cheap — you can find DIY models for $US150 or less. You should not expect to be able to cut components with it as we have done with the 2500mW or 7000mW, but there is still a wide range of applications where the low-power laser can be proficiently used with very good results.

For our first experiments we will use low-power lasers to engrave images and cut very thin materials. As there is not a Z-axis motor, we are limited to cutting very soft surfaces or engraving images on harder materials.

Following, we look at how the T2Laser Windows application works.

After testing different applications I found two of them are worth experimenting with and using

I asked the creator of T2Laser, Zax, about how the T2Laser Windows application works.

Enrico Miglino: One of the problems I always find when using programmes for controlling hardware is how to directly manage the settings. I thought it would be very useful to know when using more than one tool how to save a series of presets to work with several tools.

Zax: The profiles can be updated, if you left-click to load the values, then change whatever parameters you want (say increase from two to three passes) and then right-click to save. You can change the name if you wish and it will override the new parameters. Alternatively you can edit the T2LaserProfiles.txt file directly. It is in the T2Laser install folder. You can find this in the Users AppData folder but the name is cryptic. The simple way is to use Task Manager, right-click T2Laser and select the open folder.

Below is an example of a configuration file: Standard: 0, 255, 1000, 0.2, 0, 0, 1000

High Speed: 0, 255, 2000, 0.2, 0, 20, 1000

Fine Resolution: 0, 255, 1000, 0.1, 0, 20, 500 Cutting (two passes): 0, 255, 1000, 0.1, 2, 0, 500 Cutting (two passes with cool down): 0, 255, 1000, 0.1, 2, 20, 500

Cutting (one pass slow): 0, 255, 1000, 0.1, 0, 0, 200 Default 7: 0, 255, 1000, 0.1, 0, 20, 500 Default 8: 0, 255, 1000, 0.1, 0, 20, 500 Default 9: 0, 255, 1000, 0.1, 0, 20, 500 Default 10: 0, 255, 1000, 0.1, 0, 20, 500 Default 11: 0, 255, 1000, 0.1, 0, 20, 500 Default 12: 0, 255, 1000, 0.1, 0, 20, 500 After a few chats with Zax, I realized that he has a wide knowledge of a range of laser tools, far greater knowledge than mine. I asked him about some of his tools.

Z: I have many machines, and use T2Laser with all of them.

• EleksMaker A3 2500mW laser

• K40 CO2 40W laser with Eleks controller

• EleksDraw (pen)

• K2 CNC with Xylotex controller

• Mini CNC 3018 with Developer 2.0 (I also tested with Woodpecker board)

I just got the last one and will soon add

Z-probe features to T2Laser and I’m also considering some more CNC features.

The 2500mW laser can cut 3mm laser birch ply in six passes at 80mm/min, and it is essential to have air assist and a raised bed for the best results. I usually cut with the K40 as it is much faster, and I use the diode laser for engraving. EM: One of the issues that stops me becoming truly enthusiastic about the T2Laser programme is that it runs only on the Windows platform. Why is that? Z: I have done some research on this but think it is very difficult as much of my code is low level to improve performance and the rest is not so easy to port.

In the future, I hope to do a complete rewrite, as T2Laser has outgrown its original scope. In this case, I would consider a cross-platform alternative.

EM: In the past, we have seen how material colour has a great influence on the cutting results, due to the higher or lower compatibility of the material colour with the laser beam colour.

It is not really a great solution to paint the surface before laser cutting but this may be a good approach if we only want to engrave the surface.

Z: It works [painting the surface] on many materials that would otherwise not engrave. Some acrylic comes with a paper backing, which can be used for the same purpose, or you can place a piece of coloured paper on or beneath it. Cutting is more difficult, as this method only helps with the immediate surface so for thin materials it may be sufficient but won’t help in all cases.

The set-up used for the experiments shown in this article — a small A4-sized laser engraver equipped with a fixed laser head. The low power makes the tool easy to use for engraving or cutting soft materials

The line-art drawing used for the laser collage example. Here the drawing is shown in SVG format (the drawing format of the 3D vectorial programme Inkscape)

Below: The collage components cut on 2mm sheets of coloured polyurethane

The finished parts, ready to be assembled Below: The simple and easy to make collage composition. The layers have been glued with vinyl glue and the bottom layer has been glued on a cardboard rectangle as a support

Below: Instead of using the standard black-and-white conversion offered by the T2Laser programme, the powerful Inkscape tool Trace Bitmap can create many vectorial variations of the same photograph to experiment with and achieve different results with the laser engraving tool

Left: The original image, engraved from the black-and white conversion (on Inkscape). Using the appropriate speed the darkest parts tend to be burned creating a nice transparent effect Right: The original photograph used to engrave the red sheet of polyurethane

Above and below: After the line-art conversion of an image using Inkscape, we can use different layers to create the final image

Above and below: An example of how very different effects can be created from the same vectorial image, depending on the laser speed. Engraving materials like plastic surfaces, cardboard, and leather can be an efficient method to personalize handcrafted objects with your own artwork and logos

Above: The line-art conversion has been processed with Inkscape to extract the image contour. To do this (colours are only helpers for drawing), instead of exporting a bitmap the image is saved in DXF format, the portable 2D vectorial file that can be read by T2Laser and most of engraving programmes

It is important to consider the size and pixel resolution of the image when engraving with a bitmap before sending it to the laser programme. A common laser head is about 0.2mm wide; this means that the best resolution for the image we will use should be between 150 and 200dpi (dots per inch) for the best results

Above: The main screen of the T2Laser programme with the graphic area and a line-art image loaded

Left: The 500mW laser head. There is no motor for the Z-axis, which makes the tool better for surface work. The laser head has an adjustable lens to set the focus on the surface of the material before starting the job. You should find the smaller blue point on the surface by rotating the lens in both clockwise and counterclockwise directions

The graphic interface with a colour image automatically converted to grayscale using the programme feature

Above: The most important parameters of the programme are the beam intensity and the laser head speed. It is good practice to never set the speed over 2000mm/min to avoid compromising the quality of the job. At the highest speed, if the engraving is too dark, it is possible to reduce the beam intensity in a range between 0 and 255

Above: The second interface view of the programme. After loading the image and setting the working parameters, we should swap the interface for controlling the laser tool. The image to engrave or cut is converted to G-code, the command language most used for any kind of CNC machine (3D printers, routers, and lasers). From this interface, we can set the axis direction and origin, position the laser head on the working area, and send the G-code file to the machine. Note that the G-code can also be saved to be reused without reloading the original file