I am close to retirement and so I am trying to finish building my toys to occupy my time, I have a grizzly 3617 vertical milling machine that I converted to CNC about 15 years ago. I am in the process of upgrading it to closed loop steppers , an additional 24000 rpm water cooled spindle,  and a 20watt laser head. The original conversion included class C0 precision ball screws on axis. Most of the electronics and major mechanical work is done but now I am into the details.    I purchased my first 3d printer (ender 3 max neo) about a month ago. It has been a tremendous time and cost saver on this project. I am printing everything from timing belt pulleys for the upgraded spindle motors (it has 3 spindles)  to limit switch mounts to encoder mounts.     Not sure why I waited so long to get a 3d printer. I realize now that many, many of the parts I have machined out of metal over the years could have been printed at a fraction  of the cost and been just as durable and serviceable. A good example is the spindle timing belt drive pulleys (L100 series). The pulleys for the horizontal spindle would have cost about $125 used on ebay or $300 new. I printed them with 100% infill for $20 in filament after prototyping for about $4 with 5% infill.    That is the other advantage of 3d printing . You can rapidly prototype parts for minimal investment to refine your design before making the investment on the final piece.   On top of that you can do lithophanes. :)