I needed a proper enclosure for my bench power supply, and I figured it was the perfect excuse to put the Longer B1 40W diode laser through its paces. The machine was kindly sent to me by Simson Mall, an e-commerce platform that supplies laser engravers, 3D printers, and similar machines. So not only was I building something genuinely useful for my bench, I was also getting a thorough look at what this 40-watt laser can actually do.

If you want to make a purchase with them, you can use code "Taste The Code B1" at checkout for a 20% discount that s valid till June 31st, 2026.

What We Are Building

My existing power supply setup uses an RD6012 DC-to-DC converter, which I had been powering from a single LED power brick rated at 12 amps. The setup worked fine for everyday tasks, but being stuck at a maximum of about 13 volts was becoming a real limitation.

For the new build, I decided to run two 12V power bricks rated at 12.5 amps each, wired in series to produce 24 volts. The RD6012 can handle up to 60 volts on the input, so 24 volts is comfortably within its range and covers everything I typically work on. I also designed a center tap into the output so I can access 12 volts directly from one of the bricks without going through the converter at all, which could be useful for high-current situations where the converter would be a bottleneck.

To house all of this, I designed a wooden box roughly 22 cm wide and 24 cm long. That gives enough room for both power bricks side by side, with extra space if I ever want to add more in the future. The design also allows for vertical mounting if that becomes necessary later.

I used a web-based tool called boxes.py, hosted by the Bamberg Hacker Space, to generate the box outline with finger joints already built in. After exporting the SVG, I brought it into Illustrator to customize it. I added cutouts on the front panel for three output terminals, a slot on the back for the power switch and cable gland, and ventilation holes along the sides to let air circulate and carry away any heat buildup inside.

The Longer B1 40W Laser

Machine Overview

The B1 has a working bed of 450mm by 440mm, which is plenty for most shop projects. There is also an extended rail version available if you need to cut larger pieces. One of the first things I noticed was the integrated air assist pump, a 24V DC unit that connects directly to the machine and is controlled by it automatically. When you enable air assist in the software, the pump turns on with the job and turns off when it finishes. No separate controller needed.

A key safety feature is the key-operated lock on the front panel. The machine cannot fire the laser unless the key is inserted and turned to the green position. There is also a large emergency stop button that kills everything instantly if something goes wrong. To reset it you just rotate the button in the direction the arrows indicate.

Assembly

The B1 does not come pre-assembled, but the process is straightforward. The main steps are connecting the front and back beams to the side rails, then routing the drive belts and tensioning them properly. You want some slack in the belts, but not too much. All of the wiring comes pre-labeled, so plugging each connector into the right socket is easy. The one connector worth double-checking is the Y-axis motor, which sits at the top corner and is easy to overlook. I missed it on my first assembly and spent a moment wondering why the laser was not moving.

Software

The B1 is compatible with LightBurn and LaserGRBL, and also with a proprietary app called LaserBurn developed by Longer for their own machines. LaserBurn lets you select your exact machine and comes loaded with factory material presets. For the 40W module, those presets show it can cut up to 15mm of acrylic, 40mm of basswood, 30mm of pinewood, and 12mm of MDF. You can also specify custom speed and power settings for any material not on the list. It supports line fill, offset fill, and standard cut modes, similar to what LightBurn offers.

The machine is quite loud when running because the laser module requires significant active cooling. I kept the laser off during narrated sections throughout the video to keep the audio usable.

Cutting Tests

MDF and Plywood

I started with a piece of white MDF at 100% power and 1,000mm per minute. The cut was fast and left a clean edge with no issues. Next I tested a piece of birch plywood at 900mm per minute and 100% power. That also produced a clean, well-defined cut. Both tests matched the expected performance based on Longer's published settings.

Cutting Copper

This was the part I was most curious about. On previous machines, any PCB work involved coating the board with emulsion, exposing the design with UV, then etching the copper chemically with acid. Direct laser work on copper was not possible with lower-powered diode lasers.

With the B1, I set the material to the stainless steel profile, which runs at 100mm per minute at 100% power, and focused it onto a copper-clad board. I started the job and then hit the emergency stop when I realized it was cutting far too aggressively. It had gone completely through both the copper layer and the board backing underneath.

I backed off and ran a material test with a grid of small squares at different settings. At 200mm per minute and 100% power, it was still nearly cutting through. The charring left behind can remain electrically conductive, which is a problem for PCB work. So I switched to an engraving pass, using 1,500mm per minute at 50% power across a wider patch. After cleaning with isopropyl alcohol, most of the copper in the engraved area was gone, but a thin sliver remained in one spot that was only charred rather than fully removed. With some more testing, this could potentially work for direct PCB trace creation without any chemicals. I plan to explore the settings further off camera.

Building the Enclosure

Cutting the Parts

With the material tests done, I moved on to cutting the actual enclosure pieces. For the front panel engraving, I used 30% power at 10,000mm per minute, which is the setting Longer recommends for this type of work on this material. For the cuts themselves, I stayed with 100% power at 1,000mm per minute. Because the laser produces significant smoke, I used the enclosure I had already built for my previous machine to contain it, with smoke extraction running in the corner.

One mistake I made was loading the wrong file for the engraving step. I ended up without the voltage labels on the front panel. I will fix that in a future pass with the correct file.

Assembling the Box

After cutting, I did a dry fit and all the pieces went together perfectly. I started gluing from the sides, working around the box and applying wood glue to each joint. For the lid, which consists of two pieces, I used a stapler placed inside the box as a weight to press the panels flat while the glue set. Once fully assembled, I applied a coat of clear lacquer to seal and protect the wood.

Wiring the Power Supplies

While the lacquer dried, I got started on the wiring. Each power brick has two positive output terminals and two negative output terminals, which are bridged internally. To wire both bricks in series, I connected the positive output of one to the negative output of the other using a short jumper wire. I added ferrule crimps to the ends of all wires for a solid, vibration-resistant connection.

For the mains wiring, I used red for live and black for neutral, with a separate green wire for earth. I used slightly thinner wire on the mains side since the higher voltage means the current is lower for the same power. Even though the enclosure is made of wood, I still ran an earth connection to the metal bodies of both power supplies.

On the output side, I installed three banana-plug-style post terminals on the front panel. The left terminal is the negative, the middle is the center tap at 12 volts, and the right is the full 24-volt positive. Each terminal was secured with a washer and tightened down firmly. The mains input cable uses a plug from a PC power supply, routed through a cable gland on the back panel. The live wire passes through the power switch, then connects to both live terminals. The neutral and earth go directly to the corresponding terminals on both bricks.

Testing It Out

I plugged everything in for the first time and nothing blew up, which is always a good start. I turned the switch on and the RD6012 display lit up showing 23.77 volts. I confirmed the outputs with a multimeter: 11.9 volts between the negative and the center tap, and 23.9 volts across the full output. The small difference from the display reading is within normal tolerance. I then set a preset on the converter for 12 volts and measured exactly 12 volts at the output. Everything is working exactly as planned.

Conclusion

The Longer B1 40W laser is a capable machine that exceeded my expectations in several areas. Cutting MDF and plywood was clean and straightforward, and the copper test surprised me with how much power this machine has on tap. The finger-jointed box came together perfectly on the first cut, and the whole enclosure assembly went smoothly. The integrated air assist and safety key are both practical features I appreciate in a machine this powerful.

If you want to follow along with future builds, make sure to subscribe to the Taste The Code YouTube channel so you do not miss the next one.

Links and Resources

• Simpson Mall (Sponsor): https://simsonmall.com/
• Longer B1 40W Laser: https://simsonmall.com/products/longer-b1-laser-engraver?variant=46099991462129
• RD6012 DC-to-DC Converter: https://s.click.aliexpress.com/e/_c3sX3RPd
• 12V LED Power Brick: https://s.click.aliexpress.com/e/_c4Vvsukb
• boxes.py Box Generator: https://boxes.hackerspace-bamberg.de/
• LaserBurn Software: https://www.longer3d.com/pages/longer-app
• Banana Plug Post Terminals: https://s.click.aliexpress.com/e/_c3iqMFnl
• Cable Gland: https://s.click.aliexpress.com/e/_c4lBRefD
• Bench Power Supply: https://s.click.aliexpress.com/e/_c3BKy0aP
• Multimeter: https://s.click.aliexpress.com/e/_c3iDkk7h
• Soldering Station: https://s.click.aliexpress.com/e/_c43b2ZsB