help with changing skybox material and character material

I am making a Endless Runner and i have a delay for when the character speeds up and as he speeds up i want to change the Material for the skybox and my character.
So How do i set a delay for when i want to switch material for the skybox and character in blueprint?
I have tried to set it up like this but it does not work.

you ll need to connect the delay to something overwise it won t trigger. try to connect it to the on begin play event.