I decided to build my own piano stand, but I needed a bracket to fit the mounting holes in the piano. This bracket will fit a Yamaha P71 and P45 digital piano (possibly others). It was designed to fit two inches from the side of the stand to the center of the mounting holes on the piano, though there is a little leeway.
I used M5 x 30 mm screws to connect the bracket to the bottom of the piano and wood screws to connect it to the stand.
The bracket does not hold the weight of the piano, just stabilizes it on the stand.