Beaut pen, Roy !!
If only Santa had brought me a 3-D printer for Xmas !!!
They've really gotten cheap over the past year or so (mine was like $250). And the new resin based ones have enough precision that you don't get those lines in everything you print. What's not cheap, though, is the learning curve and time suck with all the relatively immature software bits that you have to use to do get something to print. Clearly that's not yet to a point where most would be comfortable. I guess you could sort of say the same thing with CNC routers also. And I guess that's always been said of kitless stuff - 80% of it is done off the lathe beforehand. And patience... I probably went through four iterations on these parts until everything fit like I wanted. Each one of those took 3 hours to print, which means I probably did each one of those on a different day (do the design revisions in the evening and start the print, then check the results the next morning). Oh, and the resin and part cleanup afterwords is supper messy, though does get a bit cleaner after you get the hang of it.
Another thing is that I've been spoiled by all the great people and advice on this forum. I feel like here, there's generally a pretty high standard to what people post, as far as it being good advice and accurate. By comparison, I found the various 3D resin printing communities to have way more flawed advice, flawed experiments, etc.
One cool thing I did that dawned on me midway through this one, was to print some bushings, too. Sometimes I don't use them, but generally I prefer bushings for work holding while I'm turning. I usually just whip up something temporary in maple or aluminum. But it occurred to me that I could just print them along with the parts (head slap)... and they actually worked pretty well. I did both a .25" through hole and a 60 degree cone on the end, and ended up using the 60 degree cone directly on the dead and live center. So add custom, disposable TBC bushings to the list of things you can do with a 3D printer.