Help needed to modify size of extrusion
I am 100% convinced that the course did not instruct you to design the things the way you did.
The sketches are not fully defined and it looks like you copy/pasted identical sketch items on top of each other.
I'd start from scratch!
I did not have time yesterday to continue to respond to this. Hopefully, his does not sound too negative. Making good tutorials is a lot of work. I appreciate his clear explanations and the work he put into these tutorials.
However, enthusiasm does not indicate subject matter expertise!
Due to Fusion 360s accessibility, many make well-meaning people tutorials. Many of them also use less than ideal techniques.
Before even firing up any CAD software you should start thinking about the end goal. Do you just want a digital model for visualization and rendering, or do you want to make "the thing"?
IF you do want to make it, how?
does your end product consist of different discrete parts?
Like, in this case, a box and a lid are different discrete parts and should be different components.
Once you've done that, then the next thing is to think about symmetries and patterns. Both of these considerations can help considerably reducing sketch and modeling work.
Then you might start sketching. The purpose of a sketch in CAD software is to create base geometry. As little as possible! Fewer sketch objects mean fewer constraints and dimensions are needed. This results in more stable behavior and faster performing designs, aside from being much less work.
If the part is symmetric, you might only sketch half of it and the mirror.
But don't mirror the sketch, but 3D geometry.
