Reply To: Chest Top E -> Alt S Different result

This is happening because the ’rounded planks’ are connected to the sides. But you scale them separately.

Try this: in edge select mode select the rounded edge loops like this:

Then press V.

Now you can select the rounded planks by hovering over one of the edges and press L.

Go ahead and do what you tried before: E right click (or Escape) and then Alt S.

Extrude the sides separate…