Create slider joints on two parallel shafts

[SGoldthwaite]

I'm trying to create a slider joint on the Z-axis of a desktop CNC model I iimported from Solidworks.  There are two parallel shafts and a lead screw for the z-axis.  When I make a slider joint on one of the shafts, the z-axis head rotates a bit, but that kind of makes sense since I haven't constrained it to the 2nd shaft yet.  But when I try to add a slider joint to the second axis it fails.   What's the best way to do this?

[schneik-adsk · Accepted solution]

Sliders only have one open degree of freedom, a slide along the shaft.
Change the constraint to cylindrical, so that is can slide AND rotate.

Cylindrical joints have two open degrees of freedom, translation and rotation.

[SGoldthwaite]

Thanks.  I made the two joints cylindrical and now it works.