I have four machines:
1.) Favourite - Ancient commercial Singer. Motor mounts on the ceiling, to reverse, figure eight the belt. Probably could sew planks of wood. I have used it through four layers of heavy leather, without even a hint of effort.
2.) White Jeans Machine. Nice small machine that sews well through six or seven layers of denim, canvas, or almost anything else. has button hole, zig-zag and a few other bells and whistles.
3.) Fairly modern Singer home machine. About 1985 or so. has many bells and whistles, a bunch of cams and assorted gadgets. Used mostly for light weight projects as it doesn't like more than three layers of fabric.
4.) My hands with needle and thread. Reserved for wool tartan kilts.
Slainte