I am currently rebuilding my wheelchair ramp. I am using all pressure treated lumber of course. My question is, when I install the top and bottom rails, do I cut each spindle at the angle or degree? I measured only a 10 degree angle from the main 6x6 to the middle 4x4 post. Should I cut all spindles at 10 degrees ( after cutting all to correct lenght ), or can the spindles simply be installed straight, without any angle?