flattening vector drawings

[KishZera]

Hi, 
I made the drawing below using many vector shapes, some filled shapes and some curves.  At the base layer there are some black and white circles that on top of each other give the right black and white pattern I want. I tried to export this as SVG and use it in a CNC machine to carve this out of wood, but that machine is not carving what's black in the composition, but anything black in any layer. So I need to collapse this into a single layer shape. How do I do that?
... also, the drawing is too detailed as the drill bit is wider than what I have here as minimum line width. I can't think of a good way to do that. I'll probably have to retrace it with the pen tool set to a width that matches the drill?
Thank you for your time.

[Ldina]

@KishZera I'm assuming you are using Affinity Designer for this design. I'm not an expert in this area, but I think this is correct.

You can combine all black elements into a single layer using the Boolean Add button in the top toolbar. You'd first need to convert all your text, strokes and shapes to Curves and make sure they have all been "expanded" because Boolean operations do not work on strokes (strokes will disappear if not expanded first). When you combine them, they are all given the same color, so I don't think you can have both black and white on the same layer.

I'd practice on a scrap document first to get the drill down. If you use the design you posted, I'd first put all your layers into a Group and then duplicate the Group. Lock and hide your original Group to retain it as a backup and work on the duplicate group.

Your Strokes (which have no fill....they are just paths) will need to be expanded so they have a stroke and a fill. Select one of your strokes (curves), then from the menu, Select > Select Object > Curves. With them all selected, go to Layer > Expand Stroke. This should take any strokes and covert them so they all have strokes AND fills. You will need to Expand Stoke on shapes too (ellipses, rectangles, etc). I'm not sure, but you may be able to select ALL elements in your design and do an Expand Stroke. Experiment with a test document, or perhaps someone who does more of this will weigh in..

Once all you elements have been expanded (i.e., they all have individual strokes AND fills, (even if some are set to "No fill color or No stroke color), then you can combine them into a single layer using Boolean Add. Select one of your black objects, then from the top menu, Select > Select Same > Fill Color. This will select ALL objects that have exactly the same fill color. Once they are all selected, Click on Boolean Add in the upper right of the Toolbar. All your black objects should now be combined as a single object on a single layer.

As far as I know, you cannot put the white, gray or other color elements in that same black layer. They all need to share the same properties (stroke, fill, etc), so if you were to select white and black layers and do a Boolean Add, they'd all end up being the same color (either Black or White).

You can have all Black elements on one layer, all white elements on another layer, all gray elements on another layer, etc. I'm not sure if that works with you CNC machine or not. Others may have better ideas and direct experience. I hope this at least points you in the right direction.