Want a practical, ready-to-print 150mm f/5 telescope ? Check out this project instead, that uses commonly available parts and is thought for ease of use : https://www.printables.com/model/1325533-smallest-telescope-kit-for-150750

This clip allows to pre-constrain a pair of carbon rods to add stiffness to a truss telescope. It is printed in ASA. You can use four of it, or eight, to constrain all possible pairs.