I usually avoid these threads because it’s such a complicated subject but here’s my 2 cents as an overview of sorts.
First is the answer to why this isn’t a common thing. Most probably know this by now, but the hard part of using CNC to make custom parts is you have to be able to model the parts in the computer before you can make them on the machine. Learning the software is the hardest part.
This section needs the caveat that I’m not even going to attempt to list all the cad options the ones mentioned are ones I really know or use. My answer to what is the best software? is always the one you know how to use. Also there are tons of exceptions to what is below but this is generally true.
That leads to your first question about the software. In the CNC world there’s really kind of 3 classes of modeling software or different types of cad. It’s not that one is better than the others it’s just that they serve different purposes. That being said they aren’t exclusive. Meaning you can absolutely cut a simple profile from Solidworks. But if that’s all you’re doing you don’t need a $7000 program.
You can use primarily 2D software like Audocad, Turbocad, or basically any program that will draw a line and export it in vector format. If all you want to do is cut shapes from a flat sheet. Vector programs store a line as two points with a definition telling it is a line. That’s a key for CNC work. Raster files like jpg pdf etc have to be converted to vector files. They are just stored as a collection of dots basically.
A lot of cad programs like turbocad and autocad also have some 3d capability, but usually not nearly as efficient to use as the focused 3D software. I’m not big on making recommendations, but if you don’t mind spending some money. There is a program called ActCad that is an exact copy of autocad but much cheaper and doesn’t require a subscription. It used to be $100 for the basic version (CORRECTION: it's $249US now). Nice thing about using that is it’s exactly like autocad so if you know how to use it you know autocad. This is vector 2d drafting software in general.
Here's a couple parts that were created by drawing a couple closed polylines in autocad and then exporting to simple cam software for my 3018.
Next is 3D Modeling software that is geared toward engineering. Here were talking about like Fusion 360 or Solidworks types of programs. These programs are great for drawing like mechanical parts to exact dimensions and even more complex parts that are more mathematically defined. As an example I drew all the parts to 3D print a model of the Knox tractor shown below. This isn't the completed model but about 75%
Here are some of the parts.
These programs store objects in a 3d version of vector format that defines the part mechanically.
The third is 3D sculpting software (I’m just calling it that). What I’m talking about are programs like Blender, Z-Brush and Mudbox. These programs are used for sculpting odd shaped objects. If you want to sculpt a figurehead or other decoration you need one of these programs. You can sculpt in Fusion 360, but it’s really clunky and difficult. Whereas; Blender for instance is totally designed for sculpting. (also animation and a creating video game characters etc). The sculpting software works and stores the information as a 3 dimensional mesh. Think like a ball of chicken wire.
This Lion was sculpted in Blender and added to the wall panel in Fusion 360 then machined on my 3018 Beast.
The way you go from a paper or inert plan like pdf png etc to a cnc machine is by first converting it to a vector file of some sort. The easiest way is usually to import the file into a 2d program like autocad and redraw over the plan. You can then export the vector drawing and send it to the CAM software. There is software that will convert a pdf to a vector drawing etc, but the drawings typically aren’t accurate enough to produce anything usable for machining.
You will typically find the plan is pretty distorted and you have to make a lot of tweaks to get things to fit together. You can’t just trace over the lines and expect things to fit. It’s a long involved process getting things sized so they all fit together for a model ship. Once you draw a frame you like as a closed object you can export it for the CAM software. This could then be cut out of a sheet with vertical sides.
This is a screenshot of my drawing for the Danish Bomb Vessel Den Gloende. Things like the bulkheads can be easily exported and cut on a 3018.
Here's the hull after planking.
Another option is to use a program like Fusion and take measurements from the drawing and create the model in the 3D software. If the part is fully defined in 3d you can export it to CAM software. CAM software takes the model and set up the tool paths. This software is the serious and often very expensive magic in CNC work. This is where the feeds and speeds, types of tooling and toolpaths are created. For something like just cutting flat sided shaped out of a sheet there are lots of cheap programs that will work. For true 4 axis machining the software is usually thousands of dollars.
I use Fusion 360 for my 3D modeling Software. The main reason is the approximately $500 per year subscription gives me access to professional level 3 axis and 3+1 axis CAM. 3+1 Axis is not exactly 4 axis, but it allows indexing the part on a 4th axis to you can pretty much machine anything with 3+1 axis that you can with 4 axis. The price is pretty cheap IMO for the capability you get. Most 3+1 axis or 4 axis software is crazy expensive without the high end 3D modeling software included. There's more info about the 3+1 and 4 axis stuff in the 3018 Beast thread I linked below.
Here are some parts I did in full 3d in Fusion360.
Mike Shanks machined these for the Waeslworks Fubbs project. Along with the fashion pieces wing transom etc.
For carvings I used to use mudbox, but have transitioned to Blender. Blender is free, but it’s a beast to learn to use. Partly because it does so many things that you don’t need, and partly because it just kind of works different from the engineering software I’m used to. There are a lot of good youtube tutorials for both Fusion and Blender. Once I have a mesh file sculpted in Blender I import it into Fusion 360 and use the CAM software to create the G-code.
This is far from a comprehensive explanation of what is needed, but hopefully gives an idea what is involved. I didn’t even go into machine control and types of machines and those issues. There are machines out there for around the 2K price point that will do everything a person would likely want, but there’s nothing simple about it. It isn’t really all that hard, it’s just complex.
There is a thread on here about my 3018 Beast that will give some more insight on machines.
So I decided I should just do a thread on this little project that got way out of control instead of hijacking Shota's thread. This will take several posts to get a long story up here. I’d like to preface this with a little note about me. I have an electronics background, a machining...
shipsofscale.com
, is it:
