Interesting, yeah its a 1m stick of 40x20, but I oriented the 40x20 long side up to help reduce sag from gravity. Sounds like I could benefit from it being oriented the other way to help reduce flex under belt tension. I'm going to stick with V-slot just for ease of use. At the end of the day its running a 1mm nozzle or larger, so I'm not looking for ultra precision.