More Tube Joints!

Updates for previous models made by us; the spools (TubeSpoolIdler and TubeSpoolDriver) replace the previous concave spool we made in driving our belt chain. TubeJointBasic4 is an updated version of our previous TubeJointBasic models; it now has a more rounded inner face as well as a beveled inner edge to more easily fit onto the tubes it was designed for. Both models additionally have holes for TETRIX connection, although you will need to use a wood screw for the spools.