Hi All,

I am trying to create a self-centering rack and pinion jig. I know nothing about gears so my trials have not been good. I think I have the basic concept worked out. Use two racks with a pinion at the center. I can probably maintain the rack in a parallel by using some nylon or other plastic material as spacer blocks and have other strapping (of a sort) to help create a channel for each rack to slide through. I can add a block on the end of each end to catch the sides of the extrusion I want to place a central hole in using the jig. I need to span extrusion lengths of about 48" up to about 84". I figured  that the rack segment would need to be about 48" long and the rack could be still longer without the gear travelling the full length at the ends. Hope that makes sense.

Would someone be willing to design a gear and a rack about the size of the one attached and mate them so they travel in opposite directions when the pinion is turned. I would be very grateful. I can add all the other block and strapping afterwards.