I'm working for UMBC lab peoples; they needed a means of attaching specialized grips to a PlayStation controller they rigged for their wheelchair. I designed this replacement joystick with attachments. The center post is lower than it should be in order to be printed properly; it needs to be sanded/cut by about 3mm (or just look at the actual joystick and reduce the printed one by the same amount). If the model fits too snugly in the controller, try smoothing the rounded spherical part, and reducing the center pillar on the bottom.