Laser Cutting machines come in all shapes, sizes and power outputs. Choosing a laser cutter to match your particular requirements is not always clear and choosing the wrong system could cause you significant challenges in the future. So, here’s how to choose the best laser cutting machine for you.
How to choose the best laser cutting machine for you! Finalise your budget and determine the maximum space you have available. Next, work out the largest sheet size you are likely to use and base the bed size around this. The laser power will depend on the thickest material you plan to cut. Don’t forget to budget for a water cooler and extraction.
Effectively that’s all you need to work out, but I’ll cover each item in detail further on in the post. There will also be some additional items that may not seem to be vital, but they can impact on the laser machines usability and production capacity.
Table of Contents
Your budget is obviously very personal to you, however, it will be the key factor in choosing a laser cutter and determining the system you end up with. There are 4 main bands of laser systems on the market at the moment;
- The “
eBaySpecials”, these are very basic but inexpensive machines built in China and generally based on the K40 Chassis. These can be a valid entry-level machine, but there are a number of risks involved regarding quality and reliability. I would budget for changing the Laser PSU and laser tube in the first 6 months.
- The “Red Sail Clones” direct from China, these tend to be larger units than the K40 with a lot more features. However, the same risks apply for the “eBay specials”, but if you are confident in your ability to do repair work on your laser then it is possible to get a reasonable quality machine for not a lot of cash.
- The “Red Sail Clones” via distributors or re-sellers, this is the option for those people who are risk-averse. Effectively, you are buying a Red Sail Clone through a local company, who should at least check the machines before shipping, provide installation and stock spare parts should anything go wrong. But of course, not all distributors are equal and a low purchase price should not be your one and only consideration. After-sales support is something you should research carefully, ideally contacting existing customers before making a decision.
- The “Premium Brands”, these are machines designed and manufactured typically in the USA and Europe. As expected, the quality is very good, but you pay for it. These machines can be significantly more expensive than the “Red Sail Clone” machines from distributors, sometimes double or even treble the price. However, you get quality components, improved performance and excellent support in return for that initial outlay.
Please note: a laser cutting machine is not just the laser cutter, there are some key components that are vital for its safe operation and these need to be budgeted into the price if they are not included in the standard package.
- Water cooler/chiller; this is vital for the life and performance of a glass CO2 laser tube. A bucket of water with a submersible pump is only suitable for the lowest powered machines. The cooler/chiller needs to be interlocked so that the laser will not operate if the cooler/chiller is not operating. As a rule of thumb; glass tubes up to 80-watts can use a cooler, while tubes above 80-watts need a chiller, but you will need to take into account your local climate conditions. The higher the tube power, the higher the cooling capacity required.
- Air assist pump; this helps cutting performance and reduces flare-ups (flames) at the nozzle. It also helps to keep the lens clean by providing a positive pressure to keep smoke entering the nozzle.
- Fume extraction; one of the most important safety components of a laser cutting system and the one most commonly left out due to cost. If you are running a business and have employees using the laser machine, effective extraction is not an optional extra. It can be a standalone filtration system that returns the clean air into the room or it can be one that vents to
- Venting to the atmosphere has its own issues and you need to take into account local environmental laws.
- A fire extinguisher; keep one close to the laser at all times.
Machine Location and Accessibility
Where you will site your laser machine has a huge impact on the physical size of the machine you can consider. Access is also important as the bigger the machine, the more difficult it is to get it through narrow doorways, or even worse, a flight of stairs.
If you have single doorways it may be necessary to dismantle the machine and carry it through on its side. It is very likely that the optics will need to be realigned after such an operation.
When siting a machine, you need to take into account placement of the ancillary equipment such as the air assist pump, water chiller, fume extraction and laptop/PC. I prefer to hang the air assist pump in mid-air, in order to reduce the noise generated from its vibrations. The Water chiller is generally tucked away at the back of the machine and the fume extraction unit (if used) off to one side. The fume extraction unit can make a suitable work area to place a laptop.
I would also recommend that you leave at least 12″ (300mm) space to the back and sides once the machine is in its final working location.
Maximum Sheet Size to be Used
You will obviously want to purchase a machine with a bed size that is capable of cutting the largest component you are likely to want to cut. However, it is also worthwhile checking the standard sheet sizes of the materials you are most likely to want to use. It will be cheaper in the long run if you can buy the standard, off the shelf sheet sizes rather than cut to size sheets. Even if it means paying a little extra upfront.
Choosing a machine with a pass-through port will allow you to process sheets larger than the bed size of the machine, great if you are looking to cut or engrave in the middle of a large sheet, but it’s not the easiest process to line up two sections of a job on an extra-large sheet.
However, using the pass-through port means you are using the machine in laser Class 4 mode and you will need to secure the work area and wear laser safety glasses.
The most commonly used laser powers are 25W, 40W, 50W, 60W, 80W, 100W, 130W and 150W. The higher the power the higher the cost. Don’t forget that these power values relate to the measured power out of the tube. The power at the work surface could be 10~12% lower after passing through the optical system (3 mirrors and a lens).
The most important considerations relating to the choice of laser power is whether cutting or engraving is the most important factor for your application.
- If cutting is the most important, then I would suggest getting a laser tube one level higher than that needed to cut your thickest/most difficult material at a reasonable speed.
- If engraving is the most important, then I would suggest a maximum power of 60 watts, as the lower power tubes give you a level of finesse at a low power output that you will not get with the higher powered tubes.
Unfortunately, things are not always so clear cut and sometimes you need engraving quality plus the ability to cut thicker materials so you will need to go with a higher-powered laser. Luckily there are some control systems on the market that allow you to alter and reduce the power profile for engraving, giving more control for laser engraving with a powerful laser.
So if you do need a 100W plus laser tube and want to do a lot of engraving, you need to consider machines with this engraving feature. On the Ruida controllers using the RDWorks software, it’s known as “Special Mode” and is controlled by the Facula setting of 50~99.
What Else Should You Consider for the Best Laser Cutting Machine for You?
Now that you have the basic specification of your machine sorted out, what else should you be considering?
- Warranty extension: most machines come with a minimum of 12 months warranty, now is the time to consider machines that offer longer warranties or extensions.
- Service contracts: if you are uncomfortable with servicing your machine yourself, check what offers are available when purchasing a machine.
- Auto-focus: while not vital, it is a nice function to have if you are new to laser cutting and engraving. Just make sure it’s set up correctly.
- Different lenses: Having a variety of lenses with different focal lengths can be of benefit if you are cutting a variety of materials and thicknesses. Common focal lengths are 1.5″, 2″, 2.5″ and 4″.
- Z-axis movement: having a powered Z-axis (vital for auto-focus) can be very helpful and the amount of movement (typically between 50 ~ 250 mm) will determine the tallest product you can fit in the machine.
- Rotary unit: these are great for engraving cylindrical objects, just make sure you have sufficient Z-axis clearance to fit one in your machine. It is possible to make your own rotary unit using just your laser machine.
- Cutting beds: you will typically get one or two different types of cutting bed supplied as standard, decide what you need for your applications;
- Slat bed
- Honeycomb bed
- Ventilated flat plate
- Safety glasses: only really needed if you plan to defeat the built-in safety interlocks as all laser systems should be supplied as either Class I or Class II laser safety unless otherwise stated. But safety glasses should be used if carrying out your own beam alignment.
If you are buying a European or US manufactured laser system you should expect it to have sufficient safety features built-in to satisfy current legislation. However, when it comes to laser machines manufactured in China, this is not always the case, even when these machines are sold via distributors or re-sellers. Safety will cover aspects such as electrical safety, laser safety and machine safety (moving parts) and should be a key factor in how to choose the best laser cutting machine for you.
A couple of quick and easy checks to make are as follows:
- Check the type of interlock used on the laser chamber doors. It should not be of the magnetic “reed switch” type or “limit switch” type as these are very easy to defeat. In fact these types of switches should only be used in conjunction with a key lock or if tools are required to open the doors or panels. You should be looking for something similar to a “tongue interlock switch” that needs a special “tongue” to be inserted to make an electrical circuit.
- Check for visibility of the laser nozzle. It should not be possible to see (or shine a light onto) the nozzle or the work surface directly once the doors are closed. I saw one laser machine from China that had a helpful cut-out at the base of the laser chamber door to make it easier to open with your fingers. The perfect height for a small child to peek through!
If the machine you are considering fails these basic checks, it’s probably best to consider another machine as there may be a number of additional safety issues that are not as easy to pick up with a visual inspection.
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