I’m running into a bizarre issue with this Rhino file, and I could use some help. In the layout, the hole-to-hole dimensions don’t add up to the overall dimension, which is 4".
I somehow missed this during the drawing phase, and it didn’t come up until we laser cut the part. My QC guy pointed out that the part itself has the correct dimensions, but the drawing shows impossible numbers for the hole-to-hole dimensions.
Has anyone seen something like this before? Did the laws of physics change in 2025? What gives?
Dimension objects have their own internal scale. When you pull a dimension from objects in a viewport, the dimension gets its scale from the viewport scale. If you don’t attach the dimension to an object, then it just uses the 1:1 paper scale, and if you change the viewport scale, the dimensions will no longer match the scale.
I usually start with one dimension that I know has the right scale, and then copy/paste it and adjust afterward. You can use this python script to change your dimensions scale to match your detail.
import Rhino
import rhinoscriptsyntax as rs
import scriptcontext as sc
def set_dim_scale():
def dim_filter(obj, geo, ci): return rs.IsDimension(obj)
dims = rs.GetObjects("Dimension objects", preselect=True, custom_filter="dim_filter")
if not dims:
print("Cancel")
return
detail = rs.GetObject("Detail to match", filter=32768)
if not detail:
print("Cancel")
return
detail_scale = rs.DetailScale(detail)
for dim in dims:
obj = sc.doc.Objects.Find(dim)
geo = obj.Geometry
geo.DistanceScale = 1/detail_scale
obj.CommitChanges()
if __name__ == "__main__":
set_dim_scale()
I’ve attached a modified version of your file just to demo a different approach. This might be painful or you might like it better. This utilizes Named Views and Named CPlanes, the later only being necessary in certain situations.
There’s a few strange things going on that I can’t quite decipher. The holes aren’t registering proper centers but they are allowing me to place centermarks (in model space only - I guess centermarks don’t work in layout space?). I can’t snap anything to their centers in layout space. The slot holes seem to have center snaps.
Like you I’ve been trying to find a fool-proof way to not get a bogus dimension. Luckily, the scale of my projects is so that if I accidentally dimension in layout space my dimension will be ridiculously small like 2 inches instead of 10 feet.
I’ve been leaning towards creating “reference” geometry in model space and using that to ensure I have something to snap to. I ran into this issue when trying to dimension the gauge of these holes using reference lines in layout space:
This means that I basically have to create the reference geometry for each CPlane where I am likely to encounter these issues (meaning I just take up the habit of creating it). It’s an extra step but I think once I come up with a process, including what layer to place it on (because the layer will need to be hidden often), it won’t be so bad.
