Radial Engine, 1/32 scale 3D print

[DCulp]

Just finished this 1/32 scale Pratt & Whitney Wasp Jr. radial engine. All parts shown are 3d printed on an Elegoo Mars 2 Pro. Slicing was done using Chitubox 1.9.1.










-- Dave Culp

[Andy]

That's amazing Dave. It's great to design something and then handle a real object. Must dust down my old CR10 3D printer...

[DCulp]

Thanks Andy. I really like using using AC3D for my printing work. I started using AC3D years ago for flight simulator models, so the switch to 3D printing was easy.

Most of the people in the 3D printing world are using parametric CAD, but I prefer using AC3D still. I've been using linux as my OS exclusively since the 1990's, so AC3D is perfect for me. My only real CAD option for me in the parametric CAD space is FreeCAD, which tends to be buggy. The only advantage I see to using parametric CAD is the fillets, which isn't nearly enough to get me to switch.

I do mostly resin printing, which is a good tool for making small scale model parts. One thing I discovered is that when using Chitubox as my slicer (which is free) my mesh doesn't have to be "valid". As an example I can stick a cylinder into a cube and call it done. Chitubox will slice it and I can resin print it fine. The mesh is not "valid" in that the surfaces of the cylinder don't intersect the surface of the cube with proper vertices and edges. Chitubox doesn't care about this for resin printing because all it has to do is figure out what is inside (gets resin) and what is outside (doesn't get resin). This feature saves me countless hours of CAD work.

When I print on my FDM printer it's a different story. Apparently calculating a tool path requires a "valid" mesh.

One more trick: if using the cylinder-in-a-cube example above I invert all the surfaces in the cylinder and delete the outside end cap of the cylinder, Chitubox will know I want a hole. Again, countless hours saved.


-- Dave