About this 3D model

I wanted to improve this joint component for a better fit on rods. This thing has an internal taper which allows you to slide the rod in straight for a certain distance, then it tapers towards the top for a tighter friction fit. There is now an opening in the top, so that if you want to fasten your rod into the sleeve, you can easily just poor a bit of epoxy into the opening. The exposure to air should make for a better epoxy cure than if there were no hole. This one mates perfectly with this other thing: http://www.thingiverse.com/thing:8130 The two combined form a fairly tight joint with very little wiggle.