While plywood is an excellent material for laser projects, it can throw up challenges like uneven cuts, generation of heavy smoke, and overburnt edges.
But don't worry! You can overcome these challenges by ensuring optimal parameters and establishing effective process control.
This article discusses the process of laser cutting plywood and various ways to overcome the challenges faced during the process.
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Laser Cutting Plywood: The Basics
Plywood requires high laser power to perform clean cuts with minimal burns along the edge of the cut.
Generally, a CO2 laser with a power rating of around 50W is recommended for laser cutting plywood of various thicknesses.
You can also use a 10W diode laser to cut plywood up to 6mm thick in multiple passes.
However, if your plywood has knots or glue spots under the top layer, a low-powered laser can result in incomplete cuts because knots and glue spots are comparatively more difficult to laser cut than wood.
How to Laser Cut Plywood: Step-by-Step Guide
Step 1: Prepare the Design
When preparing the design for laser cutting plywood, it is important to consider the thickness of the plywood that you plan to use for your project.
Each element of the design should be equal to or larger than the thickness of the plywood to ensure the structural integrity of the workpiece.
Moreover, large and thin sections of plywood are prone to warping and should be avoided unless you plan to provide external backing for the part to hold it straight.
Another important thing to consider is that using a low-powered laser to cut thick plywood requires multiple passes, which can often increase kerf width by overheating the workpiece.
This can often result in the loss of intricate parts of the design due to burning.
To prevent this, set the cut order in such a way that it provides ample time for the cut area to cool down before the next pass.
Step 2: Set The Optimal Parameters
|Type of laser
|CO2 or diode laser
|10W diode for DIY projects and 50W CO2 for Professional projects
|High Speed (Preferable to use multi-pass)
|As small as possible
|Strongly recommended (High pressure)
|Honeycomb or Pin table
|Needed to reduce the accumulation of smoke
Recommended parameters for laser cutting plywood
1. Set the Optimal Speed and Power
A laser cutter with a high power rating can perform through cuts in thicker plywood when compared to a low-powered laser cutter.
However, low-powered lasers can also be used to cut through thick plywood in multiple passes with a significant increase in the kerf width.
Generally, CO2 lasers with a power rating of 50W or above are recommended for plywood as they can cut through plywood of various thicknesses.
For example, with my xTool P2 55W CO2 laser I was able to cut through 10mm plywood in a single pass.
Whereas with the 20W xTool D1 Pro I was able to perform clean cuts in 6mm thick plywood in 3 passes at 500mm/min with a 30 psi air assist.
A low-powered diode laser cutter, such as Snapmaker 2.0 can also perform clean cuts in around 2mm thick plywood at cutting speed of around 300mm/min, and 3 passes.
While you can use these settings as a reference, it is always advised to perform test runs before executing the actual cut because every setup varies from the other.
2. Adjust Your laser Focus
Tight spot size is recommended for laser cutting plywood as it enables the laser to cut through plywood with a fast cutting speed.
However, when cutting thick plywood, it is advised to perform the cut in multiple passes, while adjusting the laser focus to account for the increased depth after each pass.
This ensures minimal kerf width and clean cuts.
If your laser is capable of performing a through cut in a single pass, then it is preferable to set the laser focus at the center of the thickness of the plywood to ensure minimal kerf width and clean cut.
3. Calibrate Your Air Assist
It is strongly recommended to use an air assist when laser cutting plywood to produce cleaner cuts with minimal charring.
Apart from that, air assist also prevents the smoke and debris from accumulating on the laser lens, thus prolonging the life of the laser.
If you plan to laser cut plywood without air assist, it is advised to clean the focusing lens after every cut to remove the accumulated smoke and debris.
4. Ensure Proper Exhaust
Laser-cutting plywood generates a lot of smoke.
This smoke gets trapped between the workpiece and work bed, which creates smoke stains on the back of the workpiece.
Therefore, it is preferable to use a honeycomb bed or use simple supports to elevate the workpiece from the base of the table, providing clearance for the smoke.
Moreover, it is preferable to use a proper enclosure with a good exhaust system that facilitates disposing of this smoke away from the cutting area, thereby enhancing the quality of the cut.
Step 3: Execute the Cut
Once you prepare the design and set the optimal parameters, it is time to execute the cut.
Plywood is a flammable material, so it is strictly advised to monitor the laser throughout the process.
Apart from that, the smoke produced from laser-cutting plywood can be harmful, as it contains formaldehyde-based adhesives.
So, make sure you follow proper safety during the process.
Step 4: Finish the Workpiece
Even after using the air assist, laser cutting plywood can stain the surface of the workpiece.
To remove smoke stains, you can gently sand the surface or clean the workpiece with soapy water.
Moreover, if your project involves engraved patterns, then it is preferable to seal the surface using a clear coat to prevent the engraving from scratching and smudging.
Challenges in Laser Cutting Plywood
Laser cutting plywood can produce excellent results with smooth cuts and high precision, which other traditional cutting processes cannot achieve.
However, it can throw up some challenges that you need to be wary of.
1. Edge Burns
Edge burns are one of the most common challenges in laser cutting plywood.
It leads to charring along the edge of the cut and generally occurs due to high laser power or low cutting speed.
To avoid edge burns, reducing the laser power or increasing the cutting speed, and performing the cut in multiple passes is advised.
Using the multi-pass technique helps avoid edge burns but leads to scorching of the surface.
Scorching occurs due to excessive heat produced due to multiple passes, which increases the heat-affected zone and results in burn marks on the surface of the plywood.
It is advised to use masking tape to cover the area around the cut and prevent it from overburning.
Plywood consists of multiple layers of wood bonded together by an adhesive material.
Laser cutting the layers of wood present in the plywood produces heavy smoke.
The adhesive material burns with harmful fumes and further adds to the smoke generated while laser cutting plywood.
The smoke generated due to the burning of the plywood cannot be avoided, but a good exhaust system can help with the disposal of this smoke away from the cutting area.
Furthermore, using a pin table and high-pressure air assist can improve the quality of the cut by clearing the smoke away from the workpiece.
Types of Plywood Suitable for Laser Cutting
Laser cutting plywood produces excellent results with a brownish edge that adds a bit of contrast to the cut.
Although all types of plywoods can be laser cut, some plywoods produce better results than others.
I personally prefer Birch Plywood due to its availability and laser cutting Birch plywood produces a clean cut with a light brown edge.
Furthermore, many manufacturers have introduced a special plywood series, generally known as "laser ply".
These plywoods are exclusively designed for laser cutting and produce excellent results for laser cutting and engraving.
Laser Cutting and Engraving Other Materials
Check out these guides on laser cutting some popular materials.
|Link to Guide
|Laser Cutting Paper
|Laser Cutting and Engraving Acrylic
|Laser Cutting and Engraving Aluminum
|Laser Cutting and Engraving Leather
|Laser Cutting and Engraving Plastic
|Laser cutting polypropylene
|Laser Engraving Brass
|Laser Cutting Fabric
|Laser Cutting Foam
|Laser Cutting Glass
|Laser Cutting Vinyl
Laser Cutting Guides for other Materials
Frequently Asked Questions (FAQ)
Can we laser cut hardwood?
Yes, we can laser cut hardwood. Laser cutting hardwood requires a moderately powerful CO2 or diode laser to perform clean cuts with minimal edge burns. The burning of wood produces a brownish edge that is generally desirable as it adds contrast to the project.
Can we laser engrave photographs on plywood?
Yes, we can laser engrave photographs on plywood. Laser engraving plywood produces a high-quality engraving with dark contrast, making it ideal for engraving photographs with a good level of detail.
Can we laser cut MDF?
Yes, we can laser cut MDF. Medium Density Fiberboard (MDF) is a durable material made of engineered wood fibers that produce excellent results when laser cut or engraved. Generally, a CO2 laser with a power rating of above 60W is recommended for cutting MDF boards of various thicknesses.