Trickle Vent

I've not yet printed this version, but previously tried making this as an assembly, printed in place, the tolerances were too tight, so I've reworked it into this solution.

The slider should be placed into the body with the knob through the hole, then the thin rails should clip into the end slots, there will be a little play to help with movement, but the slider should then slide with the rails as a support behind it.