Big round component with multiple edges and surfaces

Kai_himself

Hallo,
im trying to draw a big round component. I would like to cut holes in the surface, therefore i need to take messurements. 
If i try to project edges from the rounding to a new sketch, i will get mutliple edges and surfaces. 
I the illsuatration of the rounding ? 

How i should deal with it ? 

Here ist the project link.
Rinne | industrielgebiet Copy 3 (onshape.com)

dirk_van_der_vaart

Is this something for you?
https://cad.onshape.com/help/Content/projectedcurve.htm?Highlight=projected curve

Kai_himself

Thank you for your answer dirk. I dont know if thats halp me at my problem.

I made two 3-Point-Row's on my sketch and extrude it (Bild_1).

If i zoom in, the curve is divided into linearsegments (Bild_2).

I woud like to cut a hole in the bottom of the grey geoemtry. I made a new sketch on the top of the geometry, and project the two outside edges through it.

To make the meassurements i use 3-point-rows, the endpoint fits on the projected line, but it doenst fit with the outline (Bild_3).

How i insert a snapping point to that outline ?

NeilCooke

It does fit, it’s just a graphical approximation. You can increase the tessellation by changing the appearance of the part. 

dirk_van_der_vaart

Just for your inspiration.
Please check the new Part Studio, with a lot less features.
https://cad.onshape.com/documents/30d6bca4e8a257e5b0f2e4e9/w/0b8f5201cb8aee793d6cb1ea/e/55e9003c67d9e04d8c0f327f