For reference. With daily build. Single gear after implementing noted steps. OS: Ubuntu 19.04 (XFCE/ubuntustudio) Word size of OS: 64-bit Word size of FreeCAD: 64-bit Version: 0.19. Build type: Release Python version: 3.7.3 Qt version: 5.12.2 Coin version: 4.0.0a OCC version: 7.3.0 Locale: English/U...

I admit I'm having trouble visualizing what you describe.

But do you mean something like this:

So, I was following this tutorial because I can't just give up on this stuff (https://www.youtube.com/watch?v=vaAkivnTq10) and found that the diameter of the helix can not be the same as the diameter of the cylinder (for sure, nothing better than making all in approximations). And that's how you ca...

So, can't give up, but doesn't have the patience...to not give up.

Also, to answer your question about drilling them separately. Depends on your preference and the complexity of the design. :roll: Less "stuff" in a sketch is less busy and easier to see what you're doing. (less dimensions, constraint icons, etc.) For something like this it's probably a toss up, but,...

When the lines of a sketch are blue, that means they are construction geometry. Choose to toggle from/to construction mode.

The guy I was talking with wanted to design a lens and apply glass as the material...

I see this is an old post...but, I was asked this very question yesterday.

I had never tried, I have no good answer.

The reason you are stuck is many of the end points of your geometry were not coincident and thus were not constrained as yet. I would recommend you use the rectangle tool to draw rectangles, it will produce rectangles with coincident corners. I have attached my take on what you are attempting, just ...

The number/word "16 degrees" is clickable.

When you click on it, the objects that are not constrained are highlighted in green.