'I cannot draw elements with large radii in Revit'
(MEP, Architecture & Structures)
This problem came up fairly recently in a conversation, in that drawing a section of curved beam or wall with a very large radius of 18km or so. Revit would not let you enter the data saying that the maximum limit is 9144000mm! This is true however there are a couple of workarounds to this. We could get into a debate about the ability to manufacture and construct such a part to a meaningful accuracy. But I will not go there and offer the necessary suggestions instead!
The first one is Revit will let you stretch the object beyond this limit (but you cannot type the desired value in) However what you can do is stretch it to within a metre or so of the desired radius, and then offset your wall or beam by the difference, giving you the correct element parameters.
Another workaround is to go back to our old standby product of AutoCAD (or Microstation) draw the curve in that program and then import the dwg into your revit project and create your wall or beam from the pick line tool.
Although this is not ideal it is a workflow that will serve for those odd elements that have extreme values. I hope that this tip is of help and you still find Revit riveting :P