EzCad3 & JCZ

The EzCad3 Dongle, the SDK, and What They Actually Do

The EzCad3 dongle and JCZ SDK are terms you hear, but what do they actually mean for your fiber laser? We break down the hardware, the software, and the real-world implications for your workshop, including how they affect your choice of software and your engraving process.

19 October 2026 · The HagoLaser team · 9 min read

If you own a fiber laser with a JCZ controller, you have probably heard talk of the EzCad3 dongle and the JCZ SDK. These terms can feel a bit abstract, but they define how your machine works and what software you can use. Simply put, the EzCad3 dongle is the physical key that unlocks the EzCad3 software, allowing it to control your JCZ laser board. The JCZ SDK (Software Development Kit) is a separate, licensed toolkit that allows other software developers to create programs that can also talk to and control JCZ boards.

For us in the workshop, understanding this was critical. We spent too long losing sterling silver to problems that boiled down to not fully grasping how EzCad3, the dongle, and the underlying JCZ board all interacted. This article explains what we wish we had known from day one.

The EzCad3 Dongle: Your Machine's Specific Key

Think of the EzCad3 dongle like a very specific car key. You can have the right car (your laser), and you can have the right driving skills (your design and laser knowledge), but without the correct key, you cannot start the engine. The EzCad3 dongle is that key for your EzCad3 software.

What the Dongle Does

The vast majority of affordable galvo fiber lasers ship with a controller board from BJJCZ (often simply called "JCZ"), driven by their own software: EzCad2 for older LMC boards, and EzCad3 for the newer DLC/DLC2 generation. The dongle is what makes EzCad3 work with these boards.

The JCZ board itself is the true brain of your laser. The PC sends a list of vector and marking commands over USB, and the board buffers these commands, then drives the galvos and the laser source in real time. EzCad3 is simply the interface that translates your designs and settings into commands the JCZ board understands.

Remember that EzCad3 keeps your machine's critical configuration data in its PARAM folder. Files like Motors.ini (axis and focus data), MarkParamlib.ini (your parameter/pen library), your galvo correction file (.cor), and LaserPW.ini (the laser source table) are your machine's calibration. These are worth backing up before you ever make changes.

The JCZ SDK: Building Bridges to Other Software

If the EzCad3 dongle is your car key, the JCZ SDK is like a full set of blueprints, specifications, and specialized tools that JCZ provides to other engineering companies. These allow those companies to design and build their own custom engines (software) that can operate your specific car's chassis (the JCZ board).

Why the SDK Matters

It is important to state clearly that HagoLaser is not affiliated with, endorsed by, or connected to Beijing JCZ Technology Co., Ltd., nor with any laser manufacturer. EzCad and EzCad3 are trademarks of their respective owners, used descriptively only. We do not publish files belonging to JCZ/EzCad; we read the user's own installed files on the user's own machine.

Practical Impact on Your Workshop

What does this mean for us, running a jewelry workshop in Málaga, Spain, cutting and engraving sterling silver every working day?

First, it means that your choice of software is generally limited to what ships with your machine. While EzCad3 drives the hardware well, its workflow may not be optimal for everyone, especially for intricate jewelry work. However, swapping it out for another program isn't as simple as downloading a new application – that application needs to have licensed the JCZ SDK.

Second, it reinforces the importance of understanding the hardware you have. Your JCZ board and the configuration files in EzCad3's PARAM folder are the core of your machine's capabilities. Knowing where these files are and what they do is crucial for troubleshooting and consistent results.

A Note on Safety

Before we dive into operational settings, a vital reminder: a fiber marking laser is Class 4. The beam and its reflections cause permanent eye damage instantly and silently. The 1064 nm wavelength is invisible, meaning you never see the beam that blinds you. Laser safety glasses rated for 1064 nm (with an OD suitable for your source power) must be worn by everyone in the room, always. Metal is a mirror, and reflections go everywhere.

Never leave a running job unattended. Metal marking produces metal fume and fine particulate; extraction with a proper filter is health equipment, not an accessory. Physical interlocks and enclosures are the real safety layer. Software interlocks are a convenience and can be switched off – ours can. Never treat software as your protection.

Inside EzCad3: How Settings Control the Laser

Regardless of whether you use EzCad3 or another SDK-licensed program, the underlying parameters that control your laser remain the same. These settings dictate how your JCZ board instructs the galvos and the laser source. Here is a breakdown of the key parameters we use for sterling silver engraving, from our 100 W MOPA fiber laser with its 110 x 110 mm field:

For sterling silver engraving on our machine, we often use a pen with these settings. Remember, these are specific to our setup and material; you must always test on scrap before running a real piece. Test grids are invaluable for this.

Parameter Value (our machine) What it does in practice
Speed 700 mm/s How fast the galvos drag the spot. Slower means more energy per millimetre, leading to deeper and wider marks, up to the point of melting.
Power 95 % The average power output from the laser source. This is not the whole story without considering frequency.
Frequency 40 kHz The number of laser pulses per second. At a fixed average power, a higher frequency means weaker individual pulses. Conversely, a lower frequency delivers more energy per pulse.
Pulse width 200 ns (Only on MOPA sources). This controls the duration of each individual laser pulse. Longer pulses put more energy into each shot and dig deeper; shorter pulses are gentler and are often used for color marking on steel.
Passes / Loops 5 How many times the entire geometry is repeated. This is the most reliable way to achieve depth without overloading a single pass.
Jump speed 2000 mm/s How fast the galvo head travels between marks with the beam off. This is counter-intuitive but critical; if your Laser Off TC is too short, a slow jump speed can still cause faint stray lines.
Laser Off TC 100 µs The delay after the last mark of a segment BEFORE the head jumps away. Its job is to ensure the laser actually switches off. Too short, and the machine starts jumping while the beam is still live, which draws faint lines all over your work.
Polygon TC 100 µs A small settling delay at corners. It trades sharpness of corners against overall marking speed.
Min/Max jump TC 10/85 µs Small settling delays at the start and end of jumps. Like Polygon TC, these trade precision against speed.
Contour pass Enabled An extra outline pass around a filled area. EzCad3 enables it by default. It makes small text crisper and also thickens everything slightly.

Software Interlocks Are Not Real Safety

One critical lesson we learned, which touches on the software's capabilities, is about safety interlocks. On our machine, the door interlock check is enforced by EzCad3 in software, not by the controller board itself. With the door open, EzCad3 simply refuses to send the job. The board itself would have marked. We've written more about this in "Why EzCad3 Blocks Marking with the Door Open (and Why That's Not Real Safety)."

The lesson here is not that interlocks are optional. It is the opposite: if your safety depends on a software checkbox, you do not have safety. Physical enclosures, robust physical interlocks, and properly rated laser safety glasses are what protect you. Software can be reconfigured, replaced, or simply switched off.

Field Size and Power Density

Your F-theta lens sets your field: the square area the galvos can reach without moving the part. Our machine has a 110 x 110 mm field. The trade-off here is simple but crucial to understand before you buy a machine:

The smaller the field, the stronger the machine works. A shorter lens concentrates the same power into a smaller spot, meaning it cuts and engraves better. A bigger field lets you mark larger pieces but spreads the same power over a larger area, making everything weaker and coarser.

For jewelry, a small field is usually the right choice because pieces are small and you want high power density. For marking large plates, you might accept a bigger lens and slower, shallower work. Your field size lives in your own EzCad3 configuration, not just in the marketing sheet – it's worth checking what you actually have rather than what you were told.

Practical Takeaways for Your Workshop

Understanding the EzCad3 dongle and JCZ SDK ultimately comes down to practical implications for your daily work. Here are the actions we would recommend: