Unable to edit sketch dimensions?

[eliJUZP6]

Hello, I am trying to change the highlighted dimension in the picture below from 4.285 in to 3.285 in, but I keep getting an error. I have also attached the .f3z file 

[HughesTooling]

You have fixed points at both ends of the dimension. Personally I'd never used a fix constraint in a sketch, I'd always dimension the points.

[HughesTooling]

Here's one way to fully constrain the sketch by adding a few horizontal and vertical constraints plus a couple of missing tangent constraints and an angle.

[HughesTooling · Accepted solution]

You've also made a mistake using a surface revolve rather than a solid revolve. Although it creates what looks like a solid body Fusion actually see it as a surface body. This might cause problems later in the design with cuts and joins.

[eliJUZP6]

How do you dimension points?

[HughesTooling]

Here's a simplified example.

Using a vertical constraint between the origin and a point then a horizontal constraint between the origin and the other point. Then just add 2 dimensions. This will work just the same using the endpoints of lines, arcs etc. This is what I did in the image above after removing the fixed constraints you had.

Edit. To remove the fixed constraints, just right click the green points and select Fix\UnFix to toggle.

[HughesTooling · Accepted solution]

You actually have some pretty big problems with this design later in the timeline.

I would use a sketch and revolve to cut the holes in the part then use a joint to position the inserted parts. Capture positions are not parametric so edits to the design will not update, unlike joints.

So create a sketch something like this using points projected in from sketch1 for references.

Then use a revolve cut to make the hole then a joint to position the part.

Now if I edit the hole position the other component will update its position to match.

I've broken the links to the inserted parts to make it easier to share the design. I've only created one hole and joint for one component. I also recreated the revolve at the start of the timeline as a solid body. This has deleted some dependant features from the timeline. You might be better off starting again rather than trying to fix this design.