Why can't I set polygon side dimension ?

[Anonymous]

In the figure below you can see a two concentric polygons. I want to set the side of the inner one to 55. So I try to dimension it. In stead of doing that, Fusion 360 complains : “Adding this dimension will overconstraint the sketch. Choose OK to create a driven dimension”.

Then I can still change the polygon size by moving one of the sides. Hence I can make that side 55 by zooming in and carefully moving that side up and down. Hence, why does that have to be a driven dimension ? Why can't I just type in the correct value ?

Cannot set dimension

[HughesTooling]

It looks like you have used offset, are you trying to dimension the offset? Pretty sure Fusion will not let you dimension the offset copy. An offset curve can not drive its source curve.

Didn't download your f3z file as they can be problem trying to delete from my hub. In the future try temporarily breaking the links to external parts and export as an f3d.

Thanks Mark

[Anonymous]

Correct. I was mistaken. One of the polygons is an offset of the other. So, Fusion 360 is simply incapable of setting the dimensions of offsets. So I will have to replace it with a real polygon.

There are no links to external parts to delete as all the external parts have been deleted. How can one export as a f3d file ?

[HughesTooling]

Try right click on the top component in the browser and select export. If you have no external links this should let you save as an f3d.

Mark

[TheCADWhisperer]

I would have only one polygon, create feature and then Shell or Thicken or whatever to get the offset.

(Keeps the sketch simple.)

(Actually I would probably have only one line and then do above and Pattern feature(s).)

[Anonymous]

Indeed. Via a right-click menu exporting as a f3d-file is possible. Via the unnamed menu that looks like a page with a bent corner, it is not.

@TheCADWhisperer :

I don't understand what you mean.

The inner polygon is a helper polygon. It is not used as the boundary for any feature. Maybe it should have the construction line linetype.

Apparently deleting the offsetted polygon is not possible and I have to select all sections to delete them.

Now I discover that double-clicking a side selects all sides of a polygon, even when it is just an offset.

[davebYYPCU]

You can set edge length for the size of a polygon by using option 3 in the Create Polygon menu.

Might help....