For as big, bulky, and power-hungry as they were, CRTs were an analog joy of the early days of TV, video games, and computers. The crackling high-voltage, the occasional whiff of ozone, the whizzing electrons lancing through a vacuum to excite a phosphorescent image — by comparison, thin-film LCDs are sterile and boring.
Sadly, CRTs are getting harder to come by these days, and at the extreme ends of the size spectrum, may never have been available at all. Thankfully, if your project demands a retro CRT look, fitting your LCD with a custom lens might just do the trick. The link leads to the first article in a series by [jamhamster] on the travails of lensmaking, which even when not practiced for precision lens production can still be tricky. After going through the basics of material selection — acrylic, but not cold-formed, please; such sheets have internal stresses that tend to express themselves as cracks while grinding. The grinding method is as ingenious as it is simple: a blank is fitted to a flat arbor and ground down by spinning it against a belt sander, on the side without the platen. A little WD40 for lubrication and thermal management helped while progressing to finer grit belts, with a final treatment using plastic polish yielded a shape very reminiscent of an old CRT face. There’s a Twitter video that shows the simulated CRT.
Further installments of the series detail the optical properties of these lenses, options for bonding them to an LCD, and tying all the steps into a coherent method. We think the results speak for themselves, and suspect that these “emulated” CRTs often draw a double-take.
Thanks to [John] for the tip.