Cannot edit a sketch

[Anonymous]

I purchased a Fusion 36o model of a Les Paul style guitar that I am attempting to cut on the CNC. One thing the model is missing is a binding channel. My thought was to edit the sketch of the body shape, offset inward 2mm (thickness of binding) then extrude downward 6mm (width of binding) and somehow project this onto the 3d curved surface of the guitar's top surface. The ultimate goal is to create a tool path so I can cut it.
First the sketches are not editable. There is no saved history. I began saving history from the point I started working on it but that doesn't help me go back and edit the original sketches. I'm sure there is a way to achieve what I'm trying to do, but I am at my wit's end. I have attached the project file and an image of a rendering of a similar guitar showing what the binding is (the white border going around the guitar body). I know not everyone is familiar with what guitar binding is!

[davebYYPCU]

Not clear if you want the cut to conform to the 3d surface, or the current top outside edge.

In cam select the outside edge and set depth of cut into the body direction.

In Design, Use Sweep, Set profile to cutter shape, and select path.  

New sketch, Offset outside edge, then project it to contour surface, (second sketch) use it as Path for a varying height cut.

Might help....

[Anonymous]

I can't select the outside edge without also selecting the edges of the neck pocket and neck pickup cavity. This was the first thing I tried using a trace toolpath. That's why I went back to the sketch to try to create an offset and try to toolpath from there.

[jeff_strater · Accepted solution]

I assume the sketches you are referring to are those in the "3deg Neck Pitch ver" component.  Those sketches are owned by the Base Feature here:

You have to edit that base feature in order to edit those sketches.  See the screencast below.  Whoever created this design, did so as a "direct modeling" design, so those sketches are not associated with any features.  But, you should be able to edit them and do an offset, if that is the method you want to use for the binding.

[Anonymous · Accepted solution]

Hi Jeff, I think I can work with this now. I am able to edit the sketch and make extrudes. Thank you so much!