I use inventor fusion to create my master models then import into 123d for finale tweeks (can't get the same control in 123d hence the odd way to do things)
I have a part finished and I have started on the second piece but I have a confusion (still learning cad work.) Can I use Part 1 to cut a hole into Part 2?

Can do it with Blender
[youtu.be]

Here i have a link that will solve your problem definitely...

http://www.wikihow.com/Cut-a-Hole-in-an-Object-in-Adobe-Illustrator

I use OnShape.com rather than Inventor Fusion or 123D, but this is a fairly typical operation for CAD, so I'd expect any decent CAD system to support it.

Try a Boolean operation to difference one object from another.

In OnShape, there's also an operation to take one object and split it into two, along some arbitrary surface.

The OpenSCAD "difference" function is exactly this.

Use SketchUp free or Pro. Intersect faces or Boolean operations. Use x10 or x100 scale to avoid problems. Not always 100% solid, but easy to use. Diggolike, Adobe illustrator? Not for 3D I think?

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Prusa i3, Ramps 1.4. Catnozzle 0.4mm
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