Mean Well LRS-350-24 Silent PSU - Bottom Power Switch

thingiverse

This is my remix of a remix of the silent PSU mod for the Mean Well LRS-350-24 power supply, tailored specifically for Ender 3 Pros and standard Ender 3 models with an upgrade in mind. The PSU is commonly used in these printers, and I wanted to relocate it to the side of a cabinet for easy access outside of the enclosure. However, most (if not all) PSU covers that accommodate 92mm fans still have the switch and plug on the side of the unit, putting extra strain on the cord by bending it downward. By relocating the power to the bottom of the unit, the cord hangs straight down, minimizing stress on it. The large open honeycomb area allows for more efficient cooling, which I've found to be effective even without the fan kicking in during my last print. Once I attach the PSU up against my metal cabinet, cooling will become a non-issue. I made a few key modifications to this mod that differ from the original remix: - The most notable change is moving the switch cutout to the bottom end of the unit. - I extended the cover slightly longer to accommodate more wire room. - Since I couldn't modify the honeycomb, I recreated it by matching the original size and density of the pattern from the upper half of the cover. - The back cover was lengthened to fit over the new larger opening. - A hole in the back cover allows power wires to pass through into the enclosure. This hole is large enough for a rubber grommet approximately 25mm in diameter, ensuring the PSU sits flat against the enclosure. - To prevent the power cord from falling out of the socket due to gravity, I added a cable restraint component with similar honeycomb patterning. I've also included an alternative version without this feature. I encountered some issues during printing, which are visible in the photos. The slot for the cable restraint was too tight, requiring me to shave off material for it to fit properly. Similarly, the slots for alignment tabs between the two cover components were too tight as well. I've adjusted clearance in the model to ensure a better fit, but haven't printed another copy of everything to test this adjustment yet. Please let me know if the components fit together or still require adjustments so I can update the model accordingly. The cable restraint should securely clip around the cord, preventing it from slipping out. The size was measured using the original Ender 3 power cord. I used a Noctua fan (92mm NF-B9 Redux-1600 3-pin) for this project. Note that this fan does not come with a 2-pin adapter like some of the premium Noctua fans do. However, I had an adapter on hand and used it to connect to the PSU board. If you don't have one, you'll need to modify the connector or purchase an adapter. I added mesh as a filter to keep pet hair and dust out of the power supply. I picked up some 92mm fan mesh on Amazon and sandwiched one sheet between the cover and the fan. The other sheet was super-glued along the edges to the inside of the second part. The original cover screws were reused, as well as the switch and switch screws. The fan came with screws for attaching it to the PSU cover. I didn't rebuild the model for the upper half of the cover, but I would recommend adding a countersink to the screw holes so the screws sit flush with the top. If you plan to relocate your PSU to the side of a cabinet, keep in mind that the unit has mounting holes matching the socket head cap screws originally used to mount the PSU to the Ender 3 frame. These are M4 x 0.7mm screws and can be found at most hardware stores. I used shorter ones since my metal cabinet doesn't require long screws. #BIG NOTE: **I experienced issues getting the lower half (the black cover part in the images) to slice correctly in Fusion 360. If you encounter this problem, know that I had it too, and I've reported the issue to Autodesk for review. However, Cura will slice that part without any issues. No idea about other slicers.**