Modern window glass is cheap and usually flat enough for 3D printing. Mirrors need to be flatter to avoid reflective distortions and a pack of 12"X12" mirror wall tiles are a cheap optically flat surface. I recommended borosilicate glass because it's formulated to have a very low coefficient of thermal expansion. It's used in labware that can be placed directly over a burner, and it's used in furnace doors that don't break from thermal expansion over a very wide range of temperatures. The borosilicate sheets I get at McMaster-Carr are very flat.
Glass is a solid. It's an amorphous solid. There's no crystalline lattice structure but it's definitely a solid, now, and a thousand years from now. It only flows as the glass transition temperature is approached and a 3D printer won't get anywhere near that temperature. Some people get a piece of glass that's frosted on one side so they can 3D print with reportedly better adhesion and a matte finish on the frosted side and turn the glass over to get a glass smooth finish on the bottom of their prints when printing on the smooth side. I'm intrigued when I see videos where people pull their spring steel sheet off the magnetic bed and flex it to pop the prints loose, but these are covered in some polymer finish and there is some wear to the surface. They're replaceable parts, so I assume the adhesion gradually decreases over time and the build plate is replaced when the prints start failing. I don't like processes like that. Glass is forever, unless you drop it and break it. I leave mine on the printer so that's not a problem. This virtual community is great and there are many fabulous ideas shared, but it's a shame we can't meet in meat space. Chris or I, and probably many others on this list, could have your 3D printing problems sorted in no time. Much is lost in my lengthy posts. In the real world, I could show you how easy it is to print on glass, and how reliable the process is once it's dialed in and working. I CAD my parts in FreeCAD, slice the STL file in Simplify123, copy the file to the microSD card (no root privileges required), plug the card into the printer, put a thin film of glue on the glass where the part will be printed and I select the file from the front panel menu to 3D print it. No gnashing of teeth. No babysitting the printer. No parts failing to adhere to the print bed. No parts stuck to the bed after printing. Just like it ought to be. Again, if you need to apply violence when removing a part from the print bed, the bed probably isn't level after that which will cause the next print to fail. Once the process starts downhill, it's a race to the bottom after that. If you truly grok how the process works, it's not difficult to get the printer in its happy place and keep it there. On 6/15/20 8:04 PM, Gene Heskett wrote: > The glass idea seems like a good one, but is it flat enough? Glass as > you should know isn't a solid, but a supercooled liquid and will flow > sorta by the same mechanism that lets a glacier move over time, often > being twice as thick at the bottom of a light as it is at the top after > hanging vertically for 100 years. Or is that why you said borosilicate? > Its more stable? _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
