3 ms·
Float glass is pretty flat, but I'm not sure regular glass is temperature-stable enough for the task (and of course, it's fragile). Temperature-stable glass (e.
by Turing_Machine 5y ago
Float glass is pretty flat, but I'm not sure regular glass is temperature-stable enough for the task (and of course, it's fragile). Temperature-stable glass (e.g., Pyrex) usually requires a lengthy annealing stage.
Granite surface plates are pretty popular, though. Maybe glass would be okay for light duty.
Speaking of glass, amateur telescope makers can grind mirrors accurate to within 1/4 wavelength of light, using nothing but abrasive powders and patience, but they start out with a pre-cast and annealed Pyrex blank.
- Turing_Machine 5y agoI do use a piece of float glass on my 3D printer bed, and it works well enough. Maybe I'll see if I can figure out how much it distorts when heated (not enough to cause a noticeable problem with the relatively low-precision stuff I've been making thus far). Some people do use borosilicate glass (like Pyrex) for this, but I've been satisfied so far with a piece of regular float glass window stock I had cut to size at Lowes.
- jacquesm 5y agoThere are glass compositions that are very thermally stable, this is a very well researched area because so many pieces of the science puzzle depend on it.
- jacquesm 5y agoNo, but it can get you a pretty good starting point to make something that is really flat. For instance, three pieces of float glass alternated using successively finer grains will get you insane levels accuracy in a relatively short time. To the point where you'd need a laser interferometer to detect where you still have high spots.