Quote Originally Posted by curious aardvark View Post
Platform on my knp is anything but loose.
How would the size of the screw effect that ?

Other than that - yep.
Not the screw, the rods. They are a component with a major impact upon the build platform's rigidity. Larger dia Z-Axis rods (10-12mm) are more rigid, provide more surface for the (also larger) Z-Axis bearings to grab, and will not flex / sag to the same degree. I have an early version of the QiDi Tech 1. It originally came w/ 8mm rods, and when small zig-zag patterns were printed the build platform would occasionally resonate and shimmy back and forth with the extruder's motion. The extruder's X-Axis motion seemed particularly easily coupled into the build platfporm. I replaced the Z-Axis rods & bearings w/ 10mm dia and shifted to a carbon fiber print platform. No more shimmy, reduced reflection ripples in prints, and even better, I only RARELY have to re-level the platform. Here is a link for a similar upgrade kit. http://store.wmdproducts.com/index.p...&product_id=67