KillerBee Linear rail issue - Am i being fussy?

[m_c]

If the rails are preloaded (which they should be for CNC use), then they should feel a bit tight, but smooth when they move.

[ravihotwok]

Hi m_c,
the rails slide fine when they are on their own without anything bolted to them its just when everything is assembled, i think the c beams may be bent, or the steel side brackets may be slightly out or something. Was wondering if there was any tips and tricks