I am restoring a 1947 Admiral television, but the knobs were missing when I got it. So, I started working on 3D printing replacement knobs. When I was about half way done, I managed to source some original knobs, but I wanted to finish the 3D project anyway. I have posted plenty of photos, including comparisons with the genuine ones. But the photos don't do the 3D prints justice, because the glare of the flash accentuates the flaws. In normal light, they actually look quite good. I will probably use the genuine ones, except perhaps for the channel knob, because the "genuine" one is actually from a slightly different model with a darker color. For all of the inner knobs, I used metal D-shaft inserts that can be purchased online. For the outer channel knob, I included a slanted flat printed feature as a spring-lever to give the proper tension (so it doesn't just fall off of the shaft).
I speculate that perhaps if someone really wanted to push this to the limit, they could print these, coat them with a smoothing material, and then use them to make molds for resin molding. That would really come close to the original in appearance! Or, of course, if you have genuine knobs like I do, then you could just use them to make the molds.

Update: Meanwhile, I purchased a Halot One resin printer, which will be perfect for making these knobs. I already tried printing one test knob (0.01mm resolution), and it is as smooth as glass. So, when I find time, I will re-print these knobs using the Halot One, and I'll upload photos. Interesting note - UV resin apparently does not shrink as much as PLA, so I will need to either re-render the knobs or slightly scale them so that the D-shaft springs are held in tightly. Here is the link to the shaft springs: https://www.tubesandmore.com/products/knob-springs-half-moon-d-shafts

JGAurora

JGAurora JGMaker Magic

Yes

.1

Printed at 200 degrees C. 0.1mm resolution., Everything else pretty standard PLA. Used hair spray on glass to get very smooth lower surface for inner knobs. The inner channel knob and both of the outer knobs need support. the inner non-channel knob doesn't. When using support, exclude support from the central shaft opening.