Dimensions unexpected on scaled cylindrical section


#1

I extruded (Push/Pull) a circle into a vertical (parallel to the blue axis) cylinder.
I Offset the top circle and extruded that to a cylinder
I repeated several times
I used the Dimensions tool to indicate the diameters
Realizing that some of my offsets were inaccurate I selected a section and used the Scale tool to scale in the Red/Green directions.
When I go to the Dimensions tool the circles with the scaled sizes light up blue but I no longer get a diameter measurement but the length of a segment of the circular curve.
When the entire circle (which SketchUp still calls a curve) lights up I expect the dimension to be the circle’s diameter
In the attached .skp the 51.5mm dimension is one of the segments the other diameters are as expected.
Rings_mandrill.skp (45.6 KB)


#2

I can’t replicate your problem with the circle.
This is what I did.

  • draw circle > extrude face (result is a circle) > scale circle by green corner grip (result is still a circle) > scale circle in x (=green) direction (result is a curve) > scale curve in y (=red) direction (result is a circle again, thanks to SketchUp’s memory) etc.
    Somewhere along the sequence of many extrucions and scaling I also applied offset, on just the circular face as well as on a preselected circle. The result always came out as being a circle again.

I don’t know what went wrong in your model. But in SketchUp only arc entities and circle entities do have diameters or radii that can be changed in ‘Entity Info’.


#3

Hi,

I don’t know how the circle flipped into being seen as a curve by SU.

But I do wonder about the choice of scaling a circle to adjust it’s radius. It seems more reliable to me to use the radius box within the Entity Info Panel – Type in a new value there and SU adjusts things very nicely.

I also wonder if the results would have been different if the stepped cylinder was centered upon the origin point, and extruded directly along the blue axis from that position.


EDIT:

I apologize for repeating any comments already made by, Wo3Dan. I didn’t realize there was another post added to this thread… I guess I didn’t refresh the page on my browser for that to show up.


#4

Good idea I’m not accustomed to using the Entity Info box to change
dimensions so I used the Scale tool the edge control point and Ctrl then
entered values into the edit field.