If I'm reading this graph correctly the lower belt should be tensioned in order to achieve the same tension as the upper belt. But doing so results in a skewed gantry. Could something else be at play or are the differences in peak heights normal?
#vc4 500: What am I looking at?
lethal condor
lethal condor
tight grove
your shaper numbers look great which is the most important graphs. You can leave it as is and move on if you want. Otherwise you could try to tighten the lower belt one tooth. Just loosen that block just enough to be able to pull the belt and feel the one tooth "bump" through the block. I am not sure if its worth chasing with those numbers. I think most people are getting low 3k on y for 500s.