This is a Nema17 Stepper motor mounted rack and pinion.
It's part of a prototype automated IHC stainer for biomedical research.
The top piece holds the rack in place against the pinion gear.
You can add as many segments onto the rack as needed.
The second set of mounting bolts are inset under the rack.
Control interface developed in Megunolink.
Designed in TrueSpace 7.6