I've got a Mun Base with a string of 12 pylons connecting smelter, auger, telescope parts converter, launchpad and Interstellar ISRU. They are mostly linear, with the launchpads branching off from the string midway through. Each pylon has 2 pipe ends and 2 strut ends. There is some vibration in the system and some of the pylons are hovering a little, but they don't seem about to explode right away. I guess the object of building an extraplanetary launchpad is to eventually replace your Mun base with another base somewhere else. I think I can rely on KAS to support the current base until I can use Launchpads to build parts for a new base that is more planned, and that can be more mobile. Connecting 2.5m modules with rover wheels and Clampotron Sr.'s might be even less vulnerable to physics than KAS... then I can move the new base out of render range of the pylon base, except for top-ups. What is the maximum safe number of pylons?