Roland RPU-3 piano pedal characteristics mod

thingiverse

Update: added hi-res STL with lower trajectory (9.5mm at highes point) due to the problem still persisting for one of my pedals. The Roland RPU-3 is a very well built, triple piano pedal, supporting half pedalling. Unlinke many other triple pedals, it's connected via three separate TRS connectors, one for each pedal, making it suitable for use on generic keyboards, such as Kurzweil Forte. One drawback is the logarithmic characteristics (most of the resistive range applies to the first millimeters of the pedal way), and a kind of glitch at the end stop, where the resistance doesn't stay at maximum, but drops again; in my case, the MIDI value raises to 127, and then goes back again to ~108 - very annoying! Maybe Roland handles this by software in their keyboards, but that's not applicable for any generic keyboard. I therefore modified the inlays determining the potentiometers' trajectory to a slight curve and a limited actuation of the potentiometers, without limiting the pedal way. One problem still left: on Kurzweil Forte, fully pressing two pedals down the same time will cause the keyboard to do some readaption, never reaching 127 again. Will file a support request, as this doesn't look like an issue of the pedal hardware. WARNING: I don't have any long time experience concerning wear etc. By modifying your pedal, warranty will be void - therefore: do on your own risk! Important: please have a look at the post-printing section!