The high speed laser wood engraver is a demand from today’s market and is being catered by galvo CO2 lasers, among other solutions. As with any progressive market, scientific advances are made to address consumer needs and demands. The engraving and marking market faces a similar situation. Diverse requirements and customer-base has led to immense leaps in technological advancements. This was necessary to address the industry’s increased demand of sophisticated solutions for complex tasks.
From the basic hand-held rotary tool to a high-precision, computer controlled laser device; a wide variety is available for consumers to pick from. The answer to ‘which device?’ question is driven by a user’s needs and their budget. We shall be looking into high-speed engraving machines for soft materials. Soft materials can be acrylic and plastics but we will consider wood as our standard.
For extreme precision and high working speed, the market is primarily catered to by galvo CO2 laser markers. These are complemented by 3d galvo CO2 laser engravers. Let’s detour a bit before we dive deep into the dominion of galvo laser engraving and high speed laser wood engravers. A brief look into the world of wood engraving in general and where it stands today is necessary. This will help us appreciate the significance of the domain.
How Did We End Up here?
A brief look into the world of wood engraving
Wood work has been an integral part of human existence. With time, its purpose extended beyond that of just functional use. We started to use them as objects of ornament. Entire industries grew around this concept. As technology stepped in to make human life easier, we let the machines take over the heavy load. This gave us time to explore more meaningful endeavors.
Today, these tools have automated the process and made it extensively simple to execute. Using desktop laser engravers we are now able to customize gifts for loved ones. We can build functional objects on our table-tops. It is like a laser printer for wood. For those of a more curious or artistic inclination, this has opened doors to an all new platform. They can experiment with and express themselves in a new medium. Also, Youtube has a lot to offer if one wants to see laser etchers in action. It is fascinating to see these machines making complex, high precision incisions at lightning speed. People even find the videos therapeutic. From making sign boards to marking serial numbers, the usage of laser printing on wood is now common place.
The wood engraving process revolves around two basic methods. One method involves using rotary mechanical tools. The other is that of high-intensity lasers. The former method has high-torque motors, conventionally with a collet and chuck at the rotational end. The end shreds through wood making way for the required pattern. They do so using specifically designed etching bits. Laser etchers, on the other hand, slice through wood’s surface using a high-intensity light-beam. Each process has its pros and cons.
High Speed Wood Engraver’s Pros and Cons
Knowing the ups and downs helps avoid pitfalls of engraving
For rotary engravers, they come with a handful of practical advantages for a generic user. The technique is suited to almost all materials. These machines are simple to maintain and significantly less expensive than their laser counterparts.
But it does come with a few down sides. They are still slightly complex for a novice user when it comes to actual engraving. Furthermore, their resolution is limited to the size of the engraving tool tip. Also, since the system has significant vibration, a robust setup is needed. This is necessary to sustain the minute jolts and jerks the tool tip may face when coming in contact with the wood surface. Otherwise, the vibrations will translate into an imprecise etch. This consequently results in poor resolution of the markings.
High speed laser wood engravers, on the other hand, is suitable for intricate designs. The adoption of the tech side of things also has a lesser learning curve. To top it off, it is much faster than a conventional rotary setup.
Laser Types For High Speed Laser Wood Engraver
The types of lasers serving the market
Multiple laser sources are available in the market that serves the wood laser marker segment. The fore-runners in the technology that have dominated the market are CO2 lasers, fiber lasers and vandate lasers.
We’ll be discussing CO2 in greater detail below but following is a brief summary of fiber and vandate lasers.
Fiber lasers are solid state lasers that generate a laser beam roughly 100 times higher in intensity to CO2 lasers. Consequently, they are best suited to metal marking and laser etching wood using these is overkill.
Vandate, or crystal lasers, are also solid state lasers. Functionally, they offer the same operational use as that of fiber lasers. However, they comprise of expensive pump diodes that require replacement. Furthermore, the crystal itself has a short life.
CO2 Laser and Galvo Systems
What is a CO2 Laser and what guides it in 2-dimensions
A CO2 laser is a category of lasers known as gas lasers. Electricity is run through a gas-filled tube, exciting gas molecules. Afterwards, the energized particles are cooled down which release this energy in the form of light. This entire process takes place in tubes surrounded by mirrors, reflecting the emitted light multiple times. This results in a beam of light more powerful than a normal light source.
As far as power consumption considerations go, wood laser engraving machines normally operate in a range of 25-100 watts. For comparison purposes, a laser pointer operates at a few thousandths of a watt.
Now how does one get the laser to move and scan a particular path so that it can etch or engrave a piece of wood at high speed? Step in, the galvo system. The system is analogous to conventional rotary cnc where motors for each axis, x,y and z, move the engraver across the work-piece. But here, the motors precisely control a set of mirrors and at high speed. These mirrors orient the laser beam across a surface that needs marking or engraving. There are more enhanced controlling mechanisms available. One example of such a system is that of nano positioners. But their costs overshadow the benefits by quite an extent.
In a word, the Galvo Laser Systems engraving efficiency is much higher than traditional way.
Some technical details
The top contributing factors for machine sales are speed, accuracy, cost, and size. Speed or step response time is inverse in relationship to the galvo-mirror inertia and resonant frequency. It is usually defined as the duration to move to 99% of 0.1° positioning. Maximum RMS frequency is related to both the bandwidth and the capability of the galvo to dissipate the heat. The heat is caused by high currents, rate, and duty cycle. Accuracy is normally measured in terms of short-term repeatability. For users wanting to carry out alpha-numeric character marking, speed can be assessed by calculating characters per second. As discussed earlier, the higher the accuracy within galvo systems, the higher it is bound to cost.
Setting Up A High Speed Laser Wood Engraver The Right Way
Knowing which setting does what when engraving or marking
Most laser etchers have common operational settings which are briefly discussed below:
Power Setting :
• Higher power burns deeper. Too much power leads to sacrifice in detail. However, this has no effect on running time.
• Lower burns shallower. Too little power also sacrifices detail. This also does not contribute to running time.
Speed Setting :
• Higher speed settings will obviously save time. But the burns will be shallower and there will reduction in detail.
• Lower speed increases time but burns deeper. Going too deep may also reduce detail.
PPI Setting :
• Higher PPI increases the burning or melting effect. This produces finer detail if the speed is not too fast. However, this will not affect running time and will have very little effect on depth.
• Lower PPI decreases the burning or melting effect. There will be reduction in image detail if set too low. No effect on running time will take place and very little impact on depth. Very low settings are normally perforate the material.
Rule of Thumb :
• Doubling the power doubles the depth and halving the power halves the depth.
• Halving the speed doubles the depth and doubling the speed halves the depth.
Points To Ponder: Choosing The High Speed Laser Wood Engraver That Works For You
Some factors to consider when selecting a high speed laser wood engraver
Apart from power of the laser, another important consideration when selecting a wood laser machine is its bed-size. A bigger bed allows for larger work area or multiple smaller pieces in a single go. Depending on usage, a movable bed that adjusts in the z-axis is also available in certain models. This helps overcome the issue of being limited to flat materials or objects.
Following are links for some of the machines that are currently available in the market for high speed wood engraving. These are examples of what features are conventionally available and at what price point:
DremelDigiLab LC40-03 CO2 Laser Engraver ; Bed Size: 12×20 in. Laser Power: 40W CO2 Laser
This built-to-last device has high-end tech supporting the basic functions of the machine. High-res smart cameras and a 7” LCD touchscreen allows for a sophisticated experience. Notifications such as project status and similar software functions provide additional efficiency. Devil lies in the details with this unit. It costs around 6000USD per unit.
Heatsign makes multiple types of laser etching machines. Their website also contain useful content on laser engravers. The site, in general, is worth looking into for other information on wood etching process as well. They explain the types of lasers and their uses. Separate articles are also available to guide their customers depending on what industry they belong to. As a company what sets them apart is a strong customer support service.
If building things is what you like to do, here is a link for the DIY community. This brilliant web-page details how anyone can build their own version of a galvo laser engraver:
This is obviously not a CO2 laser as the design considerations for that setup are slightly more complex.
Some Material Process Considerations
Tips and tricks for a good finish on engraved wood
When using wood laser engraving, a brown residue will deposit on the surface of the wood which is normal. It is impossible to eliminate by power, speed or PPI changes. Engraving deeper and/or slower will result in more residues. Residue is easy to remove using water and a sponge. A kitchen sponge with a nylon string mesh wrapped around it is a good home-made tool. Dampen the sponge and wipe off the residue. Despite ease of availability, Paper towels and regular sponges are not the go-to tools as they lodge into the engraved area. Also, wiping them out is extremely difficult.
Another strategy is to avoid cleanup altogether by masking the wood with transfer tape and peeling it off after engraving. Applying spray paint is a good way to color fill the engraved areas before peeling off the tape. For intricate drawings there will be multiple small pieces of tape. It is easier to remove by flooding the mask with water once engraving is complete. This loosens the tape and is easy to remove by rubbing it off by hand.
Final Thoughts: High Speed Laser Wood Engraver
Let’s wrap it up
Simply put, there are a multitude of options when it comes to marking and engraving tools. A variety of technologies offering a diverse range of features are available. For high speed requirements, CO2 based laser etching and engraving machines offer an efficient solution. When it comes down to selecting the right machine, there are tradeoffs. Precision is the most obvious. A close second is speed.
However, to make the appropriate choice when selecting a laser etcher it is imperative to understand one’s requirements. For a hobbyist, a simple 200-300 USD machine would suffice. But for the industry, the figure increases exponentially. On the other hand, the ROI of the service offered using these machines sufficiently compensates for the cost. Increased speeds means more work done in the same amount of time. Reduced maintenance implies less down-time when operating machines.
All in all, laser engravers for wood are a good choice. But selecting the one with the right features is where a user needs to do some homework. Hopefully the above explanation makes taking the jump of buying one, less daunting.