I'm considering to build a slab flattening rig using V-slots. If you don't know what slab flattening rig, think of it as a human powered CNC router. The router rides in a bridge that spans two side rails. Typically everything is made from wood. The goal is to be able to flatten wood slabs that are 30" x 96" (~2.5m) and then break down the gear for storage. The 30" is not a problem. It looks like I would have to join to 1.5m pieces to get my desired length. My main ideas so far is to use side plates to secure the sections of v-slot and a plate on the bottom to register the the bottom face. Has anyone else created a gantry using v-slots longer than the stock lengths? If so how did you join the rails? did it work? I'm sure someone has already tackled this problem.
There are several other threads on the subject including: Slab Flattening Table Need help with x large build for slab flattening