Fusion 360 – Sheet metal over non-uniform planes


Sheet metal capabilities on Autodesk products have improved greatly over the years, and while it is still easier than ever to create standard designs, more complex tasks require clever workarounds to achieve the desired result.

One such case is using form modelling workspace to create a sheet metal part that sits on a non-uniform plane i.e all 4 edges of your sheet are at different angles. See below:

If we were to put a cover on the above It is not possible to create a sketch from which we can extrude or create a flange from, thus we will have to get creative to draw a correctly sized sheet of metal that covers the top of our design.

So how can we achieve this?

Start by creating a new sheet metal component.

Then move into the form modelling workspace.


Select the face tool from the ribbon and pick any angled edge as the starting plane. In this case, I have chosen the right edge.

Notice the settings I have used in the dialogue box below. Ensure that “multiple sides” option is selected and draw a rough shape to match the number of sides of your design.

Draw you face according to how many corresponding sides exist on the design you want to match.


Under the modify section (still in form model workspace), find the match tool.

When using the match tool, the aim is to “match” an edge on the face we’ve created with an edge on the main design.

  • T-spline edge – select edge of the face that we just drew
  • Target edge – select the corresponding edge of the design to which you want it fixed to
  • Click OK

Repeat the above steps for all sides.

At this point, you should have the desired fit of your cover. See below:You can now select finish form. Of course, this is only the desired face, there is no thickness associated with this face. So we can go to the solid modelling tab select create>thicken.



Select the cover face, type in your desired thickness and select OK. Ensure that it is set to create a new body and not join it to existing bodies.

And there you have it! you have created a cover for a non-uniform plane from scratch.

You can still create a flat pattern from these components, however, this will be covered in another blog in the future.