Magnetic Self-Centering Panel Door Opener

thingiverse

This mechanism enables two adjacent panel doors to swing open without requiring a knob on each door. It allows for precise adjustment to ensure flush fitting of the doors, while also returning to their center position with considerable force thanks to powerful magnets. I encountered an unusual challenge when rebuilding my daughter's mantle. Above the mantle, there was a recessed area that she didn't want to see anymore because it looked unattractive. We decided to frame it out and install two panel doors that were flush with the surrounding structure. The doors are mounted using soft-close hinges specifically designed for inset mounting. However, we didn't want to compromise the aesthetic by requiring a knob on each door. We opted for a magnetic closure (push to open and push again to close), but unfortunately, it didn't work well in conjunction with the soft-close hinges. We decided that the correct approach was to design a system where one door would be pushed in, causing the other door to pop out enough to allow users to grasp finger grooves on the side of the panel and open the door. This requirement presented a unique challenge, and I couldn't find any hardware specifically designed for this purpose. Therefore, I decided to create an opener that met these specifications. Instead of using springs, which seemed unrefined, I chose to utilize magnets to center the latch and provide the necessary force when one of the doors is pushed in. Surprisingly, this design resulted in maximum force at both open and closed positions, something not achievable with a spring closure. Moreover, I wanted to avoid the added friction caused by a spring-loaded ball mechanism. This solution worked out perfectly. The opener consists of three magnets in the base, which is mounted approximately 5/8 inch behind the panel doors. A single magnet in the hinge arm is positioned to attract the central base magnet and repel the side magnets, thus providing the centering force. The arms are offset from the center by 1.25 inches, allowing for flush adjustment of the panels using screws and an embedded nylox nut to prevent slipping. The end caps serve as a protective measure to avoid damaging the panel surface. The screws and nuts used are all #6-32 and 1.5 inches long. The magnets employed are 1/4 inch diameter x 1/4 inch long rings from K&J Magnetics (R424). When one of the doors is pushed back, the central column acts as a stop, causing the other door to be pushed forward by 1/2 inch, resulting in a total difference of 1 inch. This allows for sufficient clearance to open the other door completely. The maximum deflection angle of the hinge arm is 23 degrees, positioning the center hinge magnet at its maximum repelling distance from the side base magnet. I know this may seem like excessive detail for such a simple mechanism, but I thoroughly enjoyed designing and building it. The opener was printed using semi-transparent PETG on a Prusa I3 MK2 3D printer. I used three shells and 20% infill to ensure its strength would withstand multiple earthquakes.