Sketch quibbles

When you project bodies to make sketch lines, shouldn’t the lines be locked? I think so.

You can’t lock the diameter of a circle unless you give it a dimension (or constraint). That means if you lock all of a sketch before adding new lines with constraints, the solver can still mess with it.

You can’t lock the control points of a fit-point spline. You can’t give them symmetry constraints either.

I think you should be able to give two points a horizontal/vertical constraint without drawing a line between them.

The solver does a bad job of reading my mind. When I add a constraint, it will try every possible way to satisfy it except the one I want. I know how dumb that sounds, but it must have some way of choosing between solutions, and I wonder about its biases. Try this:

Add a tangent constraint between the line and circle.

  1. First try, it moves the circle.
  2. Lock the center point. Second try, it shifts the line, keeping its length and orientation.
  3. Lock the free end of the line. Now it resizes the circle.
  4. Lock the circle’s diameter. Now it does what I expected.

Constraint-based drawing has always sounded a lot better than it works. I usually end up adding constraints just to place things, then removing them and locking everything to keep them there. Sometimes I miss the old 2D CAD approach with snap points and everything stays where you put it.

Constraints are too limited.
Locking coordinates of constraints is a must
Locking parameters of constraints is a must
Locking single coordinate is a must
Picking and placing custom constraint points is a must
Selecting faces and custom measurement tools
Ie special circle tool for fast cimcumfriencial* coordinates is a must
That’s quite a bit but a start…

In your example:
Lock the Circle Centre
Lock the Circle Radius Dimension
Lock the Line at one end