Yes. There's really no such thing as a 2.5D router, unless the Z axis is not CNC controlled.Is it all about the code you feed it?
You just said the driving force is perimeter routing, which would be X and Y at the same time. If you're not doing carvings, the majority of what you do will fall under your "not much good" label.I can't imagine a 2.5 axis being much good...unless you can move say X and Z, or, Y and Z at the same time.
When you say 2.5D, you're talking about software. And 2.5D software is all about X and Y. Can you jump through some hoops and cheat a little. Probably, but I'm not going to go there now, because you'd really need to know what your doing.
No. Technically, it is possible, but realistically, no.If you're still with me, can I create a seat contour using software that creates 2.5axis code?
Think of 2.5D as cutting parts out of a sheet, and 3D as shaping parts. I occasionally make mouldings using 2.5D CAM, but it can be slow, tedious process. Carving a seat would be an order of magnitude harder.
2.5D CAM programs import 2D line drawings. in order to cut 3D shapes with a 2.5D CAM program, you have two complex, and important steps.
One. You need to actually draw all of your toolpaths in your 2D CAD program.
Two. You need to import that 2D drawing into a CAM program, and tell it how deep to cut each toolpath you drew, one at a time. And keep in mind that these toolpaths are X and Y only.
One thing your leaving out, which is probably the most difficult part, is that you need to create a 3D CAD model of your carved seat. Can you do that? It's not as simple as buying a CAD program and just doing it. Modeling complex shapes can take a lot of skill and experience to do.
But, once you have you're CAD model, it's a very simple process to load it into a CAM program, and create the code to carve it. And it doesn't have to be terribly expensive. programs like MeshCAM and Vectrics Cut3D can do it with no problems.
Be aware that it won't be a fast process. If you want a finished part to come off the machine, expect it to take up to an hour or more. A lot of factors can come into play, though, so time can vary by a large amount.
Anything that's not flat.Can you think of a part that can't be made with a 2.5 axis router, but can with a full 3 axis?
Unless you're very, very skilled, at both the CAD and CAM programs you're using, then you need a 3 axis CAM program.