SummaryThis one is a bit taller (one on the right in the photo) for more control than the one on the left at http://www.thingiverse.com/thing:603882
Added retainer to lock knob in place. InstructionsPrinted with no support .3mm 80% infill. Retainer can be squeezed oblong to fit over controller knob before inserting extension, then pressed into the extension to lock it in place. A dab of ABS glue if you want to make it permanent.