Excellent! Just what I had in mind putting out the Github repo. Thanks, reminds me to add those files to the Makefile.  Now I'm using scadmake, a OpenSCAD-specific make program I wrote, and it computes the dependencies at every invocation, so I lose track of the old Makefile.  If you want to try that, you can get here: https://github.com/butcherg/SCADMake Just source-code compile right now; if you're using the DRG_168 Makefile, building scadmake will be trivial. +1 on manifold.  I couldn't use my anemic tablet to do OpenSCAD work if I didn't have a version with manifold.  Hope they make a release with it soon... On 11/1/2023 2:23 PM, Curt McDowell wrote: > > Glenn, that's amazing! What a complicated and beautiful model. My dad > will love to see this. He's into model steam engines and locomotives. > I got him an Ender-3 at the age of 81 and he immediately took to OpenSCAD. > > Version 2021.01 on my Linux box took 2h 15m to build this. I had to > add rules for pilot_truck.stl and wheel_set.stl to stl/Makefile, then > was able to open stl_integration.scad in the GUI. > > Version 2023.10.31 on my Linux box with --enable=manifold took 37.4 > seconds to build the same thing. Now if 215x speedup isn't a game > changer, I don't know what is. --enable=lazy-union did not speed it up > further. > > Cheers, > Curt >