a friend of mine asked for a race style gear shifter that he could put weights in, it is fully knurled across the whole length and the knurls are the exact same size and pitch and can line up when the cap is screwed on, the only post print processing required is to run a M10 tap through it (i used a full set of starter, medium and full threaded taps as to not break the plastic) i printed mine out of Eryone Galaxy PETG and have heard no issues i also reinforced the walls towards the thread just in case, i would also like to say print at your own risk and i am also not liable for your gearstick breaking if mishandled i recommend adding supports but only applying them to the bottom taper since its footprint is so small, and just support blocking out the top thread support, i also recommend adding another support blocker and changing the per model settings on the M10 thread and increase its wall thickness