I've been looking at the JGRO for some time now, and will probably build one after I finish my CNC foam wire cutter. I have a question about the gantry uprights. On both sides of the gantry there is a 1" diameter hole that is shown on drawings dtl16 and dtl17. For the life of me I can't see what is the purpose of that hole. It is located 11" from the bottom of the gantry and 1.75" from the forward edge. It isn't for either of the x guide pipes or the x axis lead screw. Does anyone know what that hole is for?