Relate sketch entity to internal edge of a shell?

lars_busack

Hi everyone! I'm new here!

I am a CAD teacher with a SolidWorks background and I'm looking for a CAD tool that offers similar functionality, but runs on Linux Mint... ;-)
So far, onshape looks very promising to me, but I stumbled upon a 'missing feature' that is crucial in my opinion.

In short: I want to 'snap' a line to the internal edge of a pipe (the yellow lines in the picture).
It was created with the 'shell' feature, so I don't have any sketch geometry i could snap my new entites to:

I haven't found an exact answer to my quesion in the forum search, but from what I have read so far,
this function might have been left out on purpose. But I'm not sure if I'm mistaken...

Would I have to re-draw the inner edge with construction lines? If so, what about nonlinear edges?
In onshape, there seem to be no selectable edges...

This is what it would look like in SolidWorks, shift-click both lines (light blue) and set a collinear relation:

I hope I am just missing something here, this functionality would be extremely useful...

Thank you for helping me out!

Best regards,
Lars

bruce_williams

@lars_busack aka Bob Ross.

Welcome to Onshape and the forum!

You are correct - some contoured surfaces will not be selectable in the sketch.  The tools to try -  select other, use, intersect.  And of course coincident constraint once you have selectable geometry. To me the explicit construction geometry is comforting.  

bruce_williams

@lars_busack aka Bob Ross.

Welcome to Onshape and the forum!

You are correct - some contoured surfaces will not be selectable in the sketch.  The tools to try -  select other, use, intersect.  And of course coincident constraint once you have selectable geometry. To me the explicit construction geometry is comforting.  

lars_busack

Thanks for welcome and the quick answer! The 'Use' command works quite well.

I read about that in the forums, I just couldn't find it in the german Version,
but I figured out once I looked closely at the names of the features...

Again, thanks a lot!

bruce_williams

Our pleasure - this is an amazing forum of helpful people.  Glad you found the method that works; Onshape often has a different way to approach things and once you figure it out generally better.