You may be wondering what is laser cutting useful for. We are here to provide you with the necessary information. Let’s go over the suitable materials for laser cutting, its advantages over other methods and some examples how it can be best utilised with your projects.
Suitable materials for laser cutting
A wide variety of materials are suitable for laser cutting. Besides metals, those include polymers, plastics, carbon composites, ceramics etc. In this article, we are focusing on metals.
It is a good fit for cutting construction, coated and stainless steel, aluminum and copper alloys. Historically, reflective metals (aluminum, copper, polished stainless steel etc) have been more difficult to cut. But the continuous evolution of laser cutting and the emerging fiber laser technology is solving this problem.
Laser cutting’s biggest advantage compared to other thermal cutting methods is its speed and precision. The quickness is superior until certain material thickness. Therefore, we provide you with some guidance. The recommended thicknesses are:
- Construction steel – up to 20 mm
- Stainless steel – up to 20 mm
- Advanced high-strength steels (AHSS) – up to 20 mm
- Coated steel – up to 5 mm
- Aluminum – up to 12 mm
- Copper alloys – up to 5 mm
Advantages of laser cutting
You can actually choose from many options when metal cutting is necessary. Those are discussed at the end of this article. Each method has its own pros and so does laser cutting.
The main advantages of laser cutting:
- Great flexibility. One sheet may have 100 different cuts without having to change tools.
- Precision. +/- 0.1 mm gives the possibility to really cater to your most complex needs.
- Repeatability. +/- 0.05 mm ensures close to identical details.
- Speed. As said before, this is a great strength of laser cutting. Especially fast when cutting thin sheets.
- Saves money. The machines are getting more energy efficient. Shuttle tables reduce the need for handling which means less need for manual labour. Smaller manufacturing costs result in lower priced details for the buyer.
- Saving time. Laser cutting is automated. Therefore, it is the machinery that reads the drawings. The drawings only need to include cutting lines. This saves a lot of time in the drawing room.
What can laser cutting achieve?
If you’re reading this article, chances are that you are familiar to laser cutting and its uses. Still, you can always learn something new. We included a case study to exemplify a way of making everybody’s job easier.
Often times mechanical engineers sitting behind a desk only think of themselves. If you can physically assemble something, it is good enough. We dare say that is the wrong attitude.
ISO 9001 brings out the principles of a well-functioning company. An engineer is working for a company meaning he is part of a process flow. This, in turn, means that his work should not start nor end at his desk. Good practice is to think about the client, the welders, the assemblers. Laser cutting can ease the jobs of the latter and provide a satisfactory result for the customer. So designing should be done keeping all that in mind.
Laser cutting design
So here you can see an example project of a frame. I’ll try to anticipate your first thoughts – I could do it with a bandsaw and a welder for less money. Let us walk you through the design and explain the advantages step-by-step.
We tried to highlight some possible use-cases. Think along how you could implement these or similar methods to better your products.
This is a wire frame view of the legs. There are 4 square tubes that shall go through a tube laser and 2 threaded plates for adjustable legs. Let’s take a closer look at what has been done and how it benefits us.
There are notches (1) on one tube and cutouts on the other. The notches are different in length. Therefore the slot (2) will surely be facing upwards, as we want it. The welder does not have to consult the drawing for orientation or height. One less point of possible failure.
There are notches (3) used again to connect the sides and the upper beam. The gaps between the notches and holes are quite tight – the difference is 0.3 mm. The welders must hammer them in. This makes sure that the angles remain as needed.
Number 4 shows bolt holes. On the side where the thread lies, it’s 8.5 mm. The other side is 25 mm to allow tool accessibility. The bolts can fit right in and we can get a cleaner look without unnecessary bolt-heads laying around.
Rivet nut holes
The beam has 2 plates welded to both ends. Each end has notches for positioning the plates correctly. There are threaded M8 holes in both plates. The threading operation is separate. But cutting blind holes beforehand makes for easier threading and exact placing.
The upper side of the beam has hexagon (6-sided) cutouts. Those are for rivet nuts. Hexagonal rivet nuts are preferred to round ones because sliding is not a problem. It allows more flexible hole positioning than weld nuts and are easier to use. There is also an advantage when powder coating is required.
Complex shapes and the right angles
The top plate assembly consist of a plate and a sheet. The difference? Sheets are up to 6 mm. Again, we have cutouts in the plate and the sheet has notches. Good for positioning but in this case, designing for laser cutting gives another bonus.
Let’s say your manufacturer got the metal bending a few degrees off. This hurts your immaculate engineer’s eye. Yes, the notches solve it. At least up to a thickness you are able to bend without machinery.
The 3-sided box on top of the plates has our Fractory.co’s logo cut into it. Very easy with a laser cutter. No templates or print-outs are necessary.
There is still one extra operation here – chamfering. This cannot be done by laser cutting, as only cutting to normal is allowed.
The project’s overview
Our stand demonstrates the positives of a laser cutting design. It is both suitable for sheets and plates as well as tubes. What we omitted here, is another good engineering practice – limit the need for welding.
Of course, it is a standard practice. But there are many benefits to using fasteners instead:
- Keeping your assemblies/details small – good for transportation and powder coating
- Welding may bend your structure
- If you make a mistake in welding, you have to cut it up again and start over
- Those legs may be standard assemblies used at different machines. Might be good to have them coated and laying around, just waiting to get bolted to your next project
A lot of machine manufacturers confirm that many mistakes are made during the welding/assembly phase. If you followed our thought process, you can probably see how those methods benefit you with reducing these mistakes.
Notches make the positioning of parts only possible in one way. Good practices lead to simple drawings that need no more than general dimensions and numbered parts. Sure, you can add dimensions for checking. But they are not vital. There’s beauty in simplicity.
Alternative cutting methods
Sheet metal cutting can be done using various methods. If cutting to size is needed, guillotines are the most cost-effective way. Bolt-holes and the like are drilled afterwards.
Punching is another widely-used technology. It allows more complex cuts and is especially suitable with larger batch sizes of the same detail. Still, it cannot perform any cut and special tools are needed for each cutout type.
Waterjet cutting is known for its great precision and ability to cut very thick materials. It is used for both metals as well as non-metals. The edge quality depends on cutting speed – slower speeds get better results. This, in turn, means that you have to pay more for good quality. Waterjet cutting prices cannot compete with laser cutting when it comes to fulfilling your regular needs.
Gas and plasma cutting. Although the main principle is the same, the advantages are not. They are better suited for thicker materials because of their supremacy in speed there. But cutting edge quality is a sacrifice you have to bring.
Choosing the right cutting method can give you a headache. Experience is the driving factor when making those decisions. Laser cutting has its own place, and rightly so.
Giving you lots of possibilities and flexibility, it is the perfect technology for producing clean-cut tubes, sheets and plates. The applications are only limited to your imagination.
It is wise to keep yourself up to date to the latest technologies and opportunities. Also, analysing a likeable product can get you further. Reverse engineering can load you with ideas and help with designing better products.
Keeping that in mind, think how this can be achieved. If laser cutting is the answer, we are here to help you.