Similar to frame used for this printer but much improved: https://www.youtube.com/watch?v=K8644j4ouwgUses printed 6-32 threads and 10-24 or similar threaded rod for post tensioning and assembly. Very strong and rigid. Print at .3mm layer height or smaller for best quality. Printed 6-32 threads seem quite strong but do not over torque. Seems to work well enough with m4 screws as well. I may add more parts if I develop this idea further. Standard and extra strong corners and corner covers are provided.