Was just a thought after watching that video, i know i will be needing straight edges and engineer squares but most of these videos on youtube are just some guy pointing his camera at an engineer square and going up and down which lasts 20 seconds long lol. i am still reading on here and watching other people tips and tricks but all i can picture in my head is getting one rail on and have it as straight as possible on one side and bolt it down and then use the gantry to slide up and down to get the second rail inline and then bolt that down and then just use engineer squares against the aluminium beam and side plates to make sure thats square