I created this nifty little keyboard stand for my own personal use, but it was too good to keep it to myself. It holds up to 4 keyboards securely and has been tested with keyboards ranging in size from 40% up to massive 122-key IBMs. The stand is 3D printed in black PLA plastic and comes with four rubber feet attached, so it won't slide around on your desk or shelf. The bottom of each keyboard slot is lined with soft EPA foam, so your boards won't slide around either.
The unit measures 10.63" x 6.25" x 4". (270x160x102mm)