This RDS (Rotary Drive System) adapter is 12mm long and fits servos equipped with the 5mm-25T ISO micro-size spline. It attaches to our servos (8mm thick ProModeler DS115CLHV) with an M2 machine thread screw.
How do you use this thing? Common practice for using these is to glue in a short length of pultruded carbon fiber tubing (using JB Weld steel-filled epoxy), to form the basis of the linkage. From there the limits are your imagination!
Note1: micro-25T 5mm spline RDS will not fit 25T standard class servos with a 6mm spline shaft - too small.
Note2: micro-25T will not fit MKS micro-spline - ours is a touch larger.
Note3: a larger RDS is PDRS25RDS-25T for servos with ø6mm splines (sub-micro, micro, mini, and standard).