Dimension a spline lenght in a sketch?

martin_kopplow

I am currently taking Catia curses (wasn't actually my idea ...) and while I am at it, I try to do all excercises from the course again, but in Onshape, just to see how they compare. I went quite well and got as far as this one:

Task at hand is to design a simple bicycle saddle shape. One point for a profile curve is given as the curve length along the center guide spline (Pic 1). I know I can dimension an arc in an Onshape sketch (Pic 2), but even though the manual says "arc length / curve length", and I managed to create a linked copy of the spline and trimmed it, to get a point I can interactively move along the center guide spline, thereby changing the remaining spline curve lenght just nicely, I can't seem to dimension it as a curve lenght, only as a chord lenght (Pic 3). There are some more points like this in this excercise.

Did I miss somethimg here, or is it just not possible?

The latter would be a pity indeed, especially since Onshape can obviously display the curve lenght in the lower right corner of the screen (Pic 4).

If it is possible, I'd appreciate a hint.

If it is not possible yet, I'd like to request this as a feature of the dimension tool, please: "Enable driving dimension for curve lenght in sketches."

Best,

Martin

S1mon

You can dimension arc length, but not spline length. 

There's a general path length improvement request, but nothing specifically about splines (although they should be covered by this):
https://forum.onshape.com/discussion/9259/path-length-dimension

EvanReese

Actually you can also dimension sketch splines, just not paths made of many edges yet, which would rock. Just click the spline with the dimension tool.

S1mon

Ugh. I thought that had been added at some point, but somehow searching didn't get me a good answer.