What would be the smartest way to solve this? (Rotation on an arched structure)

[cagosi4788]

I need to rotate the beams that are on this arched structure so that they are 90 degrees on the arched surface. In picture they're almost 90 degrees, but off by 1 or 2 degrees, my problem is that its hard for me to get them to be exactly 90 degrees. Only way I can get them to rotate is by using the "Rotation" function, but I find this clunky as I cant use XY,XZ or YZ plane to rotate since its an arched structure. I can use the nodes around the beam to get axis beginning and axis end points, but that still becomes a bit inaccurate. Do you guys have any suggestions on how I could solve this problem to get the beams to stand 90 degrees or very close to 90 degrees?

Edit: I have tried the "GAMMA Angle" function, but it does not rotate the actual beam geometry which is what I need.

[Rafacascudo]

You will never have a perfect arch in Robot or on any similar structural software.

What you really get is a polygon. It gets closer to a circle as you increase thenumber of edges/segments

So ,Having the center of the circle ,you can draw lines to the endpoints of the arch segments.These lines will never be perpendicular to the panel surface ,for the reasons I explained above.

[cagosi4788]

I understand, what do you think about these angles? Does it look acceptable to you? I have measure the angle to the few closest nodes to the bar - seems at most its off 1.1 deg (91.1), and with one node its almost perfect 90 deg.