Big Lev Horizontal Ultrasonic Acoustic Levitator

thingiverse

This is my version of the Big Lev ultrasonic acoustic levitator: https://www.instructables.com/id/Acoustic-Levitator/ Thanks to Twitter: @AsierMarzo for making this possible. The hole spacing on various brands of transducers varies - mine have 10mm between pins (center-to-center). The diameter is 16mm and the height is 12mm. Pins are about 9mm long. A section of a sphere will have focal points for each row of transducers resulting in three distinct focal points. I adjusted the angles of the transducers to get one focal point - unsure if this improves or complicates things. The legs are designed to allow adjustment of the space between spheres. A wide range of spacings seem to work. I placed a receiver at the center of each sphere, allowing waveforms to be viewed on a scope. (I use the DSO 2250 USB by Hantek). I utilized an old Dell laptop power brick to power this setup. So I employed a DROK DC buck converter to lower the voltage to approximately 19 volts. All other components are per the instructable. There are some lines of code that need to be commented or uncommented to make the transducers visible, allowing focal points to be observed. I used $fn=180 to achieve smooth prints but be aware that rendering time for me was over four hours at this number of facets (on a fast desktop). Side note: computers with more cores do not speed up rendering in OpenSCAD as the CGAL engine is a sequential process - and cannot be parsed out to multiple processors. The spheres should be rotated in the slicer so that legs are flat on the print table and sphere is vertical, requiring no support. The caps can be printed open end up. The electronic components were mounted on Adafruit breadboards and will fit into the included tray. I added a 5v 40mm fan to cool the driver chip: at 20V and 1.2A the heat sink remains cool enough to touch.